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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-30 09:22:00 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-30 09:22:00 -0700 |
| commit | 034dd340b08be1f2f0477ad16131d609f9dbd53c (patch) | |
| tree | 2536f4b2d7893ccd916b5abdf3c454ad6edc03c2 /security/selinux | |
| download | linux-stable-034dd340b08be1f2f0477ad16131d609f9dbd53c.tar.gz linux-stable-034dd340b08be1f2f0477ad16131d609f9dbd53c.zip | |
Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted
Pull tracing fixes from Steven Rostedt:
- Fix error output of boot instance creation failure
Currently if a boot instance creation fails, instead of printing out
the name of the instance that failed, it prints "(null)". That is
because it prints "cur_str" that had already been processed by
strsep(). Print the saved name instead.
While at it, print the error code of the failure.
- Fix use-after-free for same named historgrams
Histograms can be named so that they can be used in multiple events.
But if the named histogram has a variable attached, the second event
that uses the named histogram which duplicates it and needs to free
the original after duplication leaves the old variable in place and
still visible. If another histogram uses than variable, it will use
the stale one which will try to reference the freed duplicate
histogram and crash the kernel.
Free the duplicate variables along with the duplicated histogram
data.
- Check return value of kthread_run() in event self test
The events self tests uses a kthread for testing but does not check
if it succeeded in creating a kthread. If the kthread creation were
to fail, the code will still try to call kthread_stop() on the error
returned.
- Fix race between reading trace_pipe and updating subbuffer size
If a user is reading the trace_pipe file at the same time they update
the ring buffer sub-buffer size, can cause the trace_pipe read to
read stale data. Add trace_access_lock() around updating the ring
buffer sub-buffer size.
- Fix eventfs_inode on failure path in creation of the events directory
In the creation of the "events" directory, if after allocating the
eventfs_inode a failure is detected, it calls cleanup_ei() which
calls free_ei(). The free_ei() will test if eventfs_inode being freed
has no children. It is a bug if it does. But on the failure case of
the creation of the "events" directory, the children lists have not
yet been initialized and the free will trigger a warning because
list_empty() on an uninitialized list returns false.
Move the initialization into init_ei() where it makes more sense and
makes sure that a created eventfs_inode has its lists initialized
upon creation.
- Check return value of kthread_run() in ftrace direct sample code
The sample code that shows how to use the ftrace direct calls does
not test the return of kthread_run() to see if it succeeds. Return a
failure if the kthread_run() doesn't succeed.
- Clear user events state on fork in case of alloc failure
On fork, the child gets a pointer to the parent's user events state.
It makes a copy of it then updates the child's pointer to it. But if
the allocation fails, the duplication function leaves the child with
a pointer to its parent's descriptor. When the child cleans up its
data, it will free the parent's descriptor while the parent is still
using it.
In the duplication function, set the child's user_event_mm to NULL
before testing if the allocation succeeded, and when it exits it will
not free the parent's descriptor.
- Fix retry exhaustion in simple ring buffer reader swap
simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
post-decrements it only after a failed link replacement. On the final
attempt, a successful replacement leaves retry at zero, while a
failed replacement leaves it at -1.
But the check for success expects the retry value to be non-zero and
exits with an error on zero. This is the opposite result. Fix it.
- Fail nicely when the remote swap_reader_page() returns an error
Currently, if the swap_reader_page() of a remote buffer fails, it
triggers a WARN_ON_ONCE() and continues normally. Instead, have it
exit with an error and a pr_warn() print instead of a full WARNING.
* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
ring-buffer: Stop remote reader update when page swap fails
tracing: Fix retry exhaustion in simple ring buffer reader swap
tracing/user_events: Clear copied tracing state before fork duplication
samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
eventfs: Initialize ei->children and ei->list in init_ei()
tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
tracing: Fix crash passing ERR_PTR to kthread_stop()
tracing: Fix use-after-free with same-name named triggers
tracing: Fix logged instance name on creation failure
Diffstat (limited to 'security/selinux')
59 files changed, 29349 insertions, 0 deletions
diff --git a/security/selinux/.gitignore b/security/selinux/.gitignore new file mode 100644 index 000000000..01c0df8ab --- /dev/null +++ b/security/selinux/.gitignore @@ -0,0 +1,4 @@ +# SPDX-License-Identifier: GPL-2.0-only +av_permissions.h +flask.h +/genheaders diff --git a/security/selinux/Kconfig b/security/selinux/Kconfig new file mode 100644 index 000000000..5588c4d57 --- /dev/null +++ b/security/selinux/Kconfig @@ -0,0 +1,100 @@ +# SPDX-License-Identifier: GPL-2.0-only +config SECURITY_SELINUX + bool "SELinux Support" + depends on SECURITY_NETWORK && AUDIT && NET && INET + select NETWORK_SECMARK + default n + help + This selects Security-Enhanced Linux (SELinux). + You will also need a policy configuration and a labeled filesystem. + If you are unsure how to answer this question, answer N. + +config SECURITY_SELINUX_BOOTPARAM + bool "SELinux boot parameter" + depends on SECURITY_SELINUX + default n + help + This option adds a kernel parameter 'selinux', which allows SELinux + to be disabled at boot. If this option is selected, SELinux + functionality can be disabled with selinux=0 on the kernel + command line. The purpose of this option is to allow a single + kernel image to be distributed with SELinux built in, but not + necessarily enabled. + + If you are unsure how to answer this question, answer N. + +config SECURITY_SELINUX_DEVELOP + bool "SELinux Development Support" + depends on SECURITY_SELINUX + default y + help + This enables the development support option of SELinux, + which is useful for experimenting with SELinux and developing + policies. If unsure, say Y. With this option enabled, the + kernel will start in permissive mode (log everything, deny nothing) + unless you specify enforcing=1 on the kernel command line. You + can interactively toggle the kernel between enforcing mode and + permissive mode (if permitted by the policy) via + /sys/fs/selinux/enforce. + +config SECURITY_SELINUX_AVC_STATS + bool "SELinux AVC Statistics" + depends on SECURITY_SELINUX + default y + help + This option collects access vector cache statistics to + /sys/fs/selinux/avc/cache_stats, which may be monitored via + tools such as avcstat. + +config SECURITY_SELINUX_SIDTAB_HASH_BITS + int "SELinux sidtab hashtable size" + depends on SECURITY_SELINUX + range 8 13 + default 9 + help + This option sets the number of buckets used in the sidtab hashtable + to 2^SECURITY_SELINUX_SIDTAB_HASH_BITS buckets. The number of hash + collisions may be viewed at /sys/fs/selinux/ss/sidtab_hash_stats. If + chain lengths are high (e.g. > 20) then selecting a higher value here + will ensure that lookups times are short and stable. + +config SECURITY_SELINUX_SID2STR_CACHE_SIZE + int "SELinux SID to context string translation cache size" + depends on SECURITY_SELINUX + default 256 + help + This option defines the size of the internal SID -> context string + cache, which improves the performance of context to string + conversion. Setting this option to 0 disables the cache completely. + + If unsure, keep the default value. + +config SECURITY_SELINUX_AVC_HASH_BITS + int "SELinux avc hashtable size" + depends on SECURITY_SELINUX + range 9 14 + default 9 + help + This option sets the number of buckets used in the AVC hash table + to 2^SECURITY_SELINUX_AVC_HASH_BITS. A higher value helps maintain + shorter chain lengths especially when expanding AVC nodes via + /sys/fs/selinux/avc/cache_threshold. + +config SECURITY_SELINUX_DEBUG + bool "SELinux kernel debugging support" + depends on SECURITY_SELINUX + default n + help + This enables debugging code designed to help SELinux kernel + developers, unless you know what this does in the kernel code you + should leave this disabled. + + To fine control the messages to be printed enable + CONFIG_DYNAMIC_DEBUG and see + Documentation/admin-guide/dynamic-debug-howto.rst for additional + information. + + Example usage: + + echo -n 'file "security/selinux/*" +p' > \ + /proc/dynamic_debug/control diff --git a/security/selinux/Makefile b/security/selinux/Makefile new file mode 100644 index 000000000..72d3baf79 --- /dev/null +++ b/security/selinux/Makefile @@ -0,0 +1,44 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# Makefile for building the SELinux module as part of the kernel tree. +# + +# NOTE: There are a number of improvements that can be made to this Makefile +# once the kernel requires make v4.3 or greater; the most important feature +# lacking in older versions of make is support for grouped targets. These +# improvements are noted inline in the Makefile below ... + +obj-$(CONFIG_SECURITY_SELINUX) := selinux.o + +ccflags-y := -I$(srctree)/security/selinux -I$(srctree)/security/selinux/include + +ccflags-$(CONFIG_SECURITY_SELINUX_DEBUG) += -DDEBUG + +selinux-y := avc.o hooks.o selinuxfs.o netlink.o nlmsgtab.o netif.o \ + netnode.o netport.o status.o initcalls.o \ + ss/ebitmap.o ss/hashtab.o ss/symtab.o ss/sidtab.o ss/avtab.o \ + ss/policydb.o ss/services.o ss/conditional.o ss/mls.o ss/context.o + +selinux-$(CONFIG_SECURITY_NETWORK_XFRM) += xfrm.o +selinux-$(CONFIG_NETLABEL) += netlabel.o +selinux-$(CONFIG_SECURITY_INFINIBAND) += ibpkey.o +selinux-$(CONFIG_IMA) += ima.o + +genhdrs := flask.h av_permissions.h + +# see the note above, replace the dependency rule with the one below: +# $(addprefix $(obj)/,$(selinux-y)): $(addprefix $(obj)/,$(genhdrs)) +$(addprefix $(obj)/,$(selinux-y)): $(obj)/flask.h + +quiet_cmd_genhdrs = GEN $(addprefix $(obj)/,$(genhdrs)) + cmd_genhdrs = $< $(addprefix $(obj)/,$(genhdrs)) + +targets += $(genhdrs) + +# see the note above, replace the 'flask.h' rule with the line below: +# $(addprefix $(obj)/,$(genhdrs)) &: $(obj)/genheaders FORCE +$(obj)/flask.h: $(obj)/genheaders FORCE + $(call if_changed,genhdrs) + +hostprogs := genheaders +HOST_EXTRACFLAGS += -I$(srctree)/security/selinux/include diff --git a/security/selinux/avc.c b/security/selinux/avc.c new file mode 100644 index 000000000..a9401d6c2 --- /dev/null +++ b/security/selinux/avc.c @@ -0,0 +1,1207 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Implementation of the kernel access vector cache (AVC). + * + * Authors: Stephen Smalley, <stephen.smalley.work@gmail.com> + * James Morris <jmorris@redhat.com> + * + * Update: KaiGai, Kohei <kaigai@ak.jp.nec.com> + * Replaced the avc_lock spinlock by RCU. + * + * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com> + */ +#include <linux/types.h> +#include <linux/stddef.h> +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/fs.h> +#include <linux/dcache.h> +#include <linux/init.h> +#include <linux/skbuff.h> +#include <linux/percpu.h> +#include <linux/list.h> +#include <net/sock.h> +#include <linux/un.h> +#include <net/af_unix.h> +#include <linux/ip.h> +#include <linux/audit.h> +#include <linux/ipv6.h> +#include <net/ipv6.h> +#include "avc.h" +#include "avc_ss.h" +#include "classmap.h" +#include "hash.h" + +#define CREATE_TRACE_POINTS +#include <trace/events/avc.h> + +#define AVC_CACHE_SLOTS (1 << CONFIG_SECURITY_SELINUX_AVC_HASH_BITS) +#define AVC_DEF_CACHE_THRESHOLD AVC_CACHE_SLOTS +#define AVC_CACHE_RECLAIM 16 + +#ifdef CONFIG_SECURITY_SELINUX_AVC_STATS +#define avc_cache_stats_incr(field) this_cpu_inc(avc_cache_stats.field) +#else +#define avc_cache_stats_incr(field) do {} while (0) +#endif + +struct avc_entry { + u32 ssid; + u32 tsid; + u16 tclass; + struct av_decision avd; + struct avc_xperms_node *xp_node; +}; + +struct avc_node { + struct avc_entry ae; + struct hlist_node list; /* anchored in avc_cache->slots[i] */ + struct rcu_head rhead; +}; + +struct avc_xperms_decision_node { + struct extended_perms_decision xpd; + struct list_head xpd_list; /* list of extended_perms_decision */ +}; + +struct avc_xperms_node { + struct extended_perms xp; + struct list_head xpd_head; /* list head of extended_perms_decision */ +}; + +struct avc_cache { + struct hlist_head slots[AVC_CACHE_SLOTS]; /* head for avc_node->list */ + spinlock_t slots_lock[AVC_CACHE_SLOTS]; /* lock for writes */ + atomic_t lru_hint; /* LRU hint for reclaim scan */ + atomic_t active_nodes; + u32 latest_notif; /* latest revocation notification */ +}; + +struct avc_callback_node { + int (*callback) (u32 event); + u32 events; + struct avc_callback_node *next; +}; + +#ifdef CONFIG_SECURITY_SELINUX_AVC_STATS +DEFINE_PER_CPU(struct avc_cache_stats, avc_cache_stats) = { 0 }; +#endif + +struct selinux_avc { + unsigned int avc_cache_threshold; + struct avc_cache avc_cache; +}; + +static struct selinux_avc selinux_avc; + +void selinux_avc_init(void) +{ + int i; + + selinux_avc.avc_cache_threshold = AVC_DEF_CACHE_THRESHOLD; + for (i = 0; i < AVC_CACHE_SLOTS; i++) { + INIT_HLIST_HEAD(&selinux_avc.avc_cache.slots[i]); + spin_lock_init(&selinux_avc.avc_cache.slots_lock[i]); + } + atomic_set(&selinux_avc.avc_cache.active_nodes, 0); + atomic_set(&selinux_avc.avc_cache.lru_hint, 0); +} + +unsigned int avc_get_cache_threshold(void) +{ + return selinux_avc.avc_cache_threshold; +} + +void avc_set_cache_threshold(unsigned int cache_threshold) +{ + selinux_avc.avc_cache_threshold = cache_threshold; +} + +static struct avc_callback_node *avc_callbacks __ro_after_init; +static struct kmem_cache *avc_node_cachep __ro_after_init; +static struct kmem_cache *avc_xperms_data_cachep __ro_after_init; +static struct kmem_cache *avc_xperms_decision_cachep __ro_after_init; +static struct kmem_cache *avc_xperms_cachep __ro_after_init; + +static inline u32 avc_hash(u32 ssid, u32 tsid, u16 tclass) +{ + return av_hash(ssid, tsid, (u32)tclass, (u32)(AVC_CACHE_SLOTS - 1)); +} + +/** + * avc_init - Initialize the AVC. + * + * Initialize the access vector cache. + */ +void __init avc_init(void) +{ + avc_node_cachep = KMEM_CACHE(avc_node, SLAB_PANIC); + avc_xperms_cachep = KMEM_CACHE(avc_xperms_node, SLAB_PANIC); + avc_xperms_decision_cachep = KMEM_CACHE(avc_xperms_decision_node, SLAB_PANIC); + avc_xperms_data_cachep = KMEM_CACHE(extended_perms_data, SLAB_PANIC); +} + +int avc_get_hash_stats(char *page) +{ + int i, chain_len, max_chain_len, slots_used; + struct avc_node *node; + struct hlist_head *head; + + rcu_read_lock(); + + slots_used = 0; + max_chain_len = 0; + for (i = 0; i < AVC_CACHE_SLOTS; i++) { + head = &selinux_avc.avc_cache.slots[i]; + if (!hlist_empty(head)) { + slots_used++; + chain_len = 0; + hlist_for_each_entry_rcu(node, head, list) + chain_len++; + if (chain_len > max_chain_len) + max_chain_len = chain_len; + } + } + + rcu_read_unlock(); + + return scnprintf(page, PAGE_SIZE, "entries: %d\nbuckets used: %d/%d\n" + "longest chain: %d\n", + atomic_read(&selinux_avc.avc_cache.active_nodes), + slots_used, AVC_CACHE_SLOTS, max_chain_len); +} + +/* + * using a linked list for extended_perms_decision lookup because the list is + * always small. i.e. less than 5, typically 1 + */ +static struct extended_perms_decision * +avc_xperms_decision_lookup(u8 driver, u8 base_perm, + struct avc_xperms_node *xp_node) +{ + struct avc_xperms_decision_node *xpd_node; + + list_for_each_entry(xpd_node, &xp_node->xpd_head, xpd_list) { + if (xpd_node->xpd.driver == driver && + xpd_node->xpd.base_perm == base_perm) + return &xpd_node->xpd; + } + return NULL; +} + +static inline unsigned int +avc_xperms_has_perm(struct extended_perms_decision *xpd, + u8 perm, u8 which) +{ + unsigned int rc = 0; + + if ((which == XPERMS_ALLOWED) && + (xpd->used & XPERMS_ALLOWED)) + rc = security_xperm_test(xpd->allowed->p, perm); + else if ((which == XPERMS_AUDITALLOW) && + (xpd->used & XPERMS_AUDITALLOW)) + rc = security_xperm_test(xpd->auditallow->p, perm); + else if ((which == XPERMS_DONTAUDIT) && + (xpd->used & XPERMS_DONTAUDIT)) + rc = security_xperm_test(xpd->dontaudit->p, perm); + return rc; +} + +static void avc_xperms_allow_perm(struct avc_xperms_node *xp_node, + u8 driver, u8 base_perm, u8 perm) +{ + struct extended_perms_decision *xpd; + security_xperm_set(xp_node->xp.drivers.p, driver); + xp_node->xp.base_perms |= base_perm; + xpd = avc_xperms_decision_lookup(driver, base_perm, xp_node); + if (xpd && xpd->allowed) + security_xperm_set(xpd->allowed->p, perm); +} + +static void avc_xperms_decision_free(struct avc_xperms_decision_node *xpd_node) +{ + struct extended_perms_decision *xpd; + + xpd = &xpd_node->xpd; + if (xpd->allowed) + kmem_cache_free(avc_xperms_data_cachep, xpd->allowed); + if (xpd->auditallow) + kmem_cache_free(avc_xperms_data_cachep, xpd->auditallow); + if (xpd->dontaudit) + kmem_cache_free(avc_xperms_data_cachep, xpd->dontaudit); + kmem_cache_free(avc_xperms_decision_cachep, xpd_node); +} + +static void avc_xperms_free(struct avc_xperms_node *xp_node) +{ + struct avc_xperms_decision_node *xpd_node, *tmp; + + if (!xp_node) + return; + + list_for_each_entry_safe(xpd_node, tmp, &xp_node->xpd_head, xpd_list) { + list_del(&xpd_node->xpd_list); + avc_xperms_decision_free(xpd_node); + } + kmem_cache_free(avc_xperms_cachep, xp_node); +} + +static void avc_copy_xperms_decision(struct extended_perms_decision *dest, + struct extended_perms_decision *src) +{ + dest->base_perm = src->base_perm; + dest->driver = src->driver; + dest->used = src->used; + if (dest->used & XPERMS_ALLOWED) + memcpy(dest->allowed->p, src->allowed->p, + sizeof(src->allowed->p)); + if (dest->used & XPERMS_AUDITALLOW) + memcpy(dest->auditallow->p, src->auditallow->p, + sizeof(src->auditallow->p)); + if (dest->used & XPERMS_DONTAUDIT) + memcpy(dest->dontaudit->p, src->dontaudit->p, + sizeof(src->dontaudit->p)); +} + +/* + * similar to avc_copy_xperms_decision, but only copy decision + * information relevant to this perm + */ +static inline void avc_quick_copy_xperms_decision(u8 perm, + struct extended_perms_decision *dest, + struct extended_perms_decision *src) +{ + /* + * compute index of the u32 of the 256 bits (8 u32s) that contain this + * command permission + */ + u8 i = perm >> 5; + + dest->base_perm = src->base_perm; + dest->used = src->used; + if (dest->used & XPERMS_ALLOWED) + dest->allowed->p[i] = src->allowed->p[i]; + if (dest->used & XPERMS_AUDITALLOW) + dest->auditallow->p[i] = src->auditallow->p[i]; + if (dest->used & XPERMS_DONTAUDIT) + dest->dontaudit->p[i] = src->dontaudit->p[i]; +} + +static struct avc_xperms_decision_node + *avc_xperms_decision_alloc(u8 which) +{ + struct avc_xperms_decision_node *xpd_node; + struct extended_perms_decision *xpd; + + xpd_node = kmem_cache_zalloc(avc_xperms_decision_cachep, GFP_NOWAIT); + if (!xpd_node) + return NULL; + + xpd = &xpd_node->xpd; + if (which & XPERMS_ALLOWED) { + xpd->allowed = kmem_cache_zalloc(avc_xperms_data_cachep, + GFP_NOWAIT); + if (!xpd->allowed) + goto error; + } + if (which & XPERMS_AUDITALLOW) { + xpd->auditallow = kmem_cache_zalloc(avc_xperms_data_cachep, + GFP_NOWAIT); + if (!xpd->auditallow) + goto error; + } + if (which & XPERMS_DONTAUDIT) { + xpd->dontaudit = kmem_cache_zalloc(avc_xperms_data_cachep, + GFP_NOWAIT); + if (!xpd->dontaudit) + goto error; + } + return xpd_node; +error: + avc_xperms_decision_free(xpd_node); + return NULL; +} + +static int avc_add_xperms_decision(struct avc_node *node, + struct extended_perms_decision *src) +{ + struct avc_xperms_decision_node *dest_xpd; + + dest_xpd = avc_xperms_decision_alloc(src->used); + if (!dest_xpd) + return -ENOMEM; + avc_copy_xperms_decision(&dest_xpd->xpd, src); + list_add(&dest_xpd->xpd_list, &node->ae.xp_node->xpd_head); + node->ae.xp_node->xp.len++; + return 0; +} + +static struct avc_xperms_node *avc_xperms_alloc(void) +{ + struct avc_xperms_node *xp_node; + + xp_node = kmem_cache_zalloc(avc_xperms_cachep, GFP_NOWAIT); + if (!xp_node) + return xp_node; + INIT_LIST_HEAD(&xp_node->xpd_head); + return xp_node; +} + +static int avc_xperms_populate(struct avc_node *node, + struct avc_xperms_node *src) +{ + struct avc_xperms_node *dest; + struct avc_xperms_decision_node *dest_xpd; + struct avc_xperms_decision_node *src_xpd; + + if (src->xp.len == 0) + return 0; + dest = avc_xperms_alloc(); + if (!dest) + return -ENOMEM; + + memcpy(dest->xp.drivers.p, src->xp.drivers.p, sizeof(dest->xp.drivers.p)); + dest->xp.len = src->xp.len; + dest->xp.base_perms = src->xp.base_perms; + + /* for each source xpd allocate a destination xpd and copy */ + list_for_each_entry(src_xpd, &src->xpd_head, xpd_list) { + dest_xpd = avc_xperms_decision_alloc(src_xpd->xpd.used); + if (!dest_xpd) + goto error; + avc_copy_xperms_decision(&dest_xpd->xpd, &src_xpd->xpd); + list_add(&dest_xpd->xpd_list, &dest->xpd_head); + } + node->ae.xp_node = dest; + return 0; +error: + avc_xperms_free(dest); + return -ENOMEM; + +} + +static inline u32 avc_xperms_audit_required(u32 requested, + struct av_decision *avd, + struct extended_perms_decision *xpd, + u8 perm, + int result, + u32 *deniedp) +{ + u32 denied, audited; + + denied = requested & ~avd->allowed; + if (unlikely(denied)) { + audited = denied & avd->auditdeny; + if (audited && xpd) { + if (avc_xperms_has_perm(xpd, perm, XPERMS_DONTAUDIT)) + audited = 0; + } + } else if (result) { + audited = denied = requested; + } else { + audited = requested & avd->auditallow; + if (audited && xpd) { + if (!avc_xperms_has_perm(xpd, perm, XPERMS_AUDITALLOW)) + audited = 0; + } + } + + *deniedp = denied; + return audited; +} + +static inline int avc_xperms_audit(u32 ssid, u32 tsid, u16 tclass, + u32 requested, struct av_decision *avd, + struct extended_perms_decision *xpd, + u8 perm, int result, + struct common_audit_data *ad) +{ + u32 audited, denied; + + audited = avc_xperms_audit_required( + requested, avd, xpd, perm, result, &denied); + if (likely(!audited)) + return 0; + return slow_avc_audit(ssid, tsid, tclass, requested, + audited, denied, result, ad); +} + +static void avc_node_free(struct rcu_head *rhead) +{ + struct avc_node *node = container_of(rhead, struct avc_node, rhead); + avc_xperms_free(node->ae.xp_node); + kmem_cache_free(avc_node_cachep, node); + avc_cache_stats_incr(frees); +} + +static void avc_node_delete(struct avc_node *node) +{ + hlist_del_rcu(&node->list); + call_rcu(&node->rhead, avc_node_free); + atomic_dec(&selinux_avc.avc_cache.active_nodes); +} + +static void avc_node_kill(struct avc_node *node) +{ + avc_xperms_free(node->ae.xp_node); + kmem_cache_free(avc_node_cachep, node); + avc_cache_stats_incr(frees); + atomic_dec(&selinux_avc.avc_cache.active_nodes); +} + +static void avc_node_replace(struct avc_node *new, struct avc_node *old) +{ + hlist_replace_rcu(&old->list, &new->list); + call_rcu(&old->rhead, avc_node_free); + atomic_dec(&selinux_avc.avc_cache.active_nodes); +} + +static inline int avc_reclaim_node(void) +{ + struct avc_node *node; + int hvalue, try, ecx; + unsigned long flags; + struct hlist_head *head; + spinlock_t *lock; + + for (try = 0, ecx = 0; try < AVC_CACHE_SLOTS; try++) { + hvalue = atomic_inc_return(&selinux_avc.avc_cache.lru_hint) & + (AVC_CACHE_SLOTS - 1); + head = &selinux_avc.avc_cache.slots[hvalue]; + lock = &selinux_avc.avc_cache.slots_lock[hvalue]; + + if (!spin_trylock_irqsave(lock, flags)) + continue; + + rcu_read_lock(); + hlist_for_each_entry(node, head, list) { + avc_node_delete(node); + avc_cache_stats_incr(reclaims); + ecx++; + if (ecx >= AVC_CACHE_RECLAIM) { + rcu_read_unlock(); + spin_unlock_irqrestore(lock, flags); + goto out; + } + } + rcu_read_unlock(); + spin_unlock_irqrestore(lock, flags); + } +out: + return ecx; +} + +static struct avc_node *avc_alloc_node(void) +{ + struct avc_node *node; + + node = kmem_cache_zalloc(avc_node_cachep, GFP_NOWAIT); + if (!node) + return NULL; + + INIT_HLIST_NODE(&node->list); + avc_cache_stats_incr(allocations); + + if (atomic_inc_return(&selinux_avc.avc_cache.active_nodes) > + selinux_avc.avc_cache_threshold) + avc_reclaim_node(); + + return node; +} + +static void avc_node_populate(struct avc_node *node, u32 ssid, u32 tsid, u16 tclass, struct av_decision *avd) +{ + node->ae.ssid = ssid; + node->ae.tsid = tsid; + node->ae.tclass = tclass; + memcpy(&node->ae.avd, avd, sizeof(node->ae.avd)); +} + +static inline struct avc_node *avc_search_node(u32 ssid, u32 tsid, u16 tclass) +{ + struct avc_node *node, *ret = NULL; + u32 hvalue; + struct hlist_head *head; + + hvalue = avc_hash(ssid, tsid, tclass); + head = &selinux_avc.avc_cache.slots[hvalue]; + hlist_for_each_entry_rcu(node, head, list) { + if (ssid == node->ae.ssid && + tclass == node->ae.tclass && + tsid == node->ae.tsid) { + ret = node; + break; + } + } + + return ret; +} + +/** + * avc_lookup - Look up an AVC entry. + * @ssid: source security identifier + * @tsid: target security identifier + * @tclass: target security class + * + * Look up an AVC entry that is valid for the + * (@ssid, @tsid), interpreting the permissions + * based on @tclass. If a valid AVC entry exists, + * then this function returns the avc_node. + * Otherwise, this function returns NULL. + */ +static struct avc_node *avc_lookup(u32 ssid, u32 tsid, u16 tclass) +{ + struct avc_node *node; + + avc_cache_stats_incr(lookups); + node = avc_search_node(ssid, tsid, tclass); + + if (node) + return node; + + avc_cache_stats_incr(misses); + return NULL; +} + +static int avc_latest_notif_update(u32 seqno, int is_insert) +{ + int ret = 0; + static DEFINE_SPINLOCK(notif_lock); + unsigned long flag; + + spin_lock_irqsave(¬if_lock, flag); + if (is_insert) { + if (seqno < selinux_avc.avc_cache.latest_notif) { + pr_warn("SELinux: avc: seqno %d < latest_notif %d\n", + seqno, selinux_avc.avc_cache.latest_notif); + ret = -EAGAIN; + } + } else { + if (seqno > selinux_avc.avc_cache.latest_notif) + selinux_avc.avc_cache.latest_notif = seqno; + } + spin_unlock_irqrestore(¬if_lock, flag); + + return ret; +} + +/** + * avc_insert - Insert an AVC entry. + * @ssid: source security identifier + * @tsid: target security identifier + * @tclass: target security class + * @avd: resulting av decision + * @xp_node: resulting extended permissions + * + * Insert an AVC entry for the SID pair + * (@ssid, @tsid) and class @tclass. + * The access vectors and the sequence number are + * normally provided by the security server in + * response to a security_compute_av() call. If the + * sequence number @avd->seqno is not less than the latest + * revocation notification, then the function copies + * the access vectors into a cache entry. + */ +static void avc_insert(u32 ssid, u32 tsid, u16 tclass, + struct av_decision *avd, struct avc_xperms_node *xp_node) +{ + struct avc_node *pos, *node = NULL; + u32 hvalue; + unsigned long flag; + spinlock_t *lock; + struct hlist_head *head; + + if (avc_latest_notif_update(avd->seqno, 1)) + return; + + node = avc_alloc_node(); + if (!node) + return; + + avc_node_populate(node, ssid, tsid, tclass, avd); + if (avc_xperms_populate(node, xp_node)) { + avc_node_kill(node); + return; + } + + hvalue = avc_hash(ssid, tsid, tclass); + head = &selinux_avc.avc_cache.slots[hvalue]; + lock = &selinux_avc.avc_cache.slots_lock[hvalue]; + spin_lock_irqsave(lock, flag); + hlist_for_each_entry(pos, head, list) { + if (pos->ae.ssid == ssid && + pos->ae.tsid == tsid && + pos->ae.tclass == tclass) { + avc_node_replace(node, pos); + goto found; + } + } + hlist_add_head_rcu(&node->list, head); +found: + spin_unlock_irqrestore(lock, flag); +} + +/** + * avc_audit_pre_callback - SELinux specific information + * will be called by generic audit code + * @ab: the audit buffer + * @a: audit_data + */ +static void avc_audit_pre_callback(struct audit_buffer *ab, void *a) +{ + struct common_audit_data *ad = a; + struct selinux_audit_data *sad = ad->selinux_audit_data; + u32 av = sad->audited, perm; + const char *const *perms; + u32 i; + + audit_log_format(ab, "avc: %s ", sad->denied ? "denied" : "granted"); + + if (av == 0) { + audit_log_format(ab, " null"); + return; + } + + perms = secclass_map[sad->tclass-1].perms; + + audit_log_format(ab, " {"); + i = 0; + perm = 1; + while (i < (sizeof(av) * 8)) { + if ((perm & av) && perms[i]) { + audit_log_format(ab, " %s", perms[i]); + av &= ~perm; + } + i++; + perm <<= 1; + } + + if (av) + audit_log_format(ab, " 0x%x", av); + + audit_log_format(ab, " } for "); +} + +/** + * avc_audit_post_callback - SELinux specific information + * will be called by generic audit code + * @ab: the audit buffer + * @a: audit_data + */ +static void avc_audit_post_callback(struct audit_buffer *ab, void *a) +{ + struct common_audit_data *ad = a; + struct selinux_audit_data *sad = ad->selinux_audit_data; + char *scontext = NULL; + char *tcontext = NULL; + const char *tclass = NULL; + u32 scontext_len; + u32 tcontext_len; + int rc; + + rc = security_sid_to_context(sad->ssid, &scontext, + &scontext_len); + if (rc) + audit_log_format(ab, " ssid=%d", sad->ssid); + else + audit_log_format(ab, " scontext=%s", scontext); + + rc = security_sid_to_context(sad->tsid, &tcontext, + &tcontext_len); + if (rc) + audit_log_format(ab, " tsid=%d", sad->tsid); + else + audit_log_format(ab, " tcontext=%s", tcontext); + + tclass = secclass_map[sad->tclass-1].name; + audit_log_format(ab, " tclass=%s", tclass); + + if (sad->denied) + audit_log_format(ab, " permissive=%u", sad->result ? 0 : 1); + + trace_selinux_audited(sad, scontext, tcontext, tclass); + kfree(tcontext); + kfree(scontext); + + /* in case of invalid context report also the actual context string */ + rc = security_sid_to_context_inval(sad->ssid, &scontext, + &scontext_len); + if (!rc && scontext) { + if (scontext_len && scontext[scontext_len - 1] == '\0') + scontext_len--; + audit_log_format(ab, " srawcon="); + audit_log_n_untrustedstring(ab, scontext, scontext_len); + kfree(scontext); + } + + rc = security_sid_to_context_inval(sad->tsid, &scontext, + &scontext_len); + if (!rc && scontext) { + if (scontext_len && scontext[scontext_len - 1] == '\0') + scontext_len--; + audit_log_format(ab, " trawcon="); + audit_log_n_untrustedstring(ab, scontext, scontext_len); + kfree(scontext); + } +} + +/* + * This is the slow part of avc audit with big stack footprint. + * Note that it is non-blocking and can be called from under + * rcu_read_lock(). + */ +noinline int slow_avc_audit(u32 ssid, u32 tsid, u16 tclass, + u32 requested, u32 audited, u32 denied, int result, + struct common_audit_data *a) +{ + struct common_audit_data stack_data; + struct selinux_audit_data sad; + + if (WARN_ON(!tclass || tclass >= ARRAY_SIZE(secclass_map))) + return -EINVAL; + + if (!a) { + a = &stack_data; + a->type = LSM_AUDIT_DATA_NONE; + } + + sad.tclass = tclass; + sad.requested = requested; + sad.ssid = ssid; + sad.tsid = tsid; + sad.audited = audited; + sad.denied = denied; + sad.result = result; + + a->selinux_audit_data = &sad; + + common_lsm_audit(a, avc_audit_pre_callback, avc_audit_post_callback); + return 0; +} + +/** + * avc_add_callback - Register a callback for security events. + * @callback: callback function + * @events: security events + * + * Register a callback function for events in the set @events. + * Returns %0 on success or -%ENOMEM if insufficient memory + * exists to add the callback. + */ +int __init avc_add_callback(int (*callback)(u32 event), u32 events) +{ + struct avc_callback_node *c; + int rc = 0; + + c = kmalloc_obj(*c); + if (!c) { + rc = -ENOMEM; + goto out; + } + + c->callback = callback; + c->events = events; + c->next = avc_callbacks; + avc_callbacks = c; +out: + return rc; +} + +/** + * avc_update_node - Update an AVC entry + * @event : Updating event + * @perms : Permission mask bits + * @driver: xperm driver information + * @base_perm: the base permission associated with the extended permission + * @xperm: xperm permissions + * @ssid: AVC entry source sid + * @tsid: AVC entry target sid + * @tclass : AVC entry target object class + * @seqno : sequence number when decision was made + * @xpd: extended_perms_decision to be added to the node + * @flags: the AVC_* flags, e.g. AVC_EXTENDED_PERMS, or 0. + * + * if a valid AVC entry doesn't exist,this function returns -ENOENT. + * if kmalloc() called internal returns NULL, this function returns -ENOMEM. + * otherwise, this function updates the AVC entry. The original AVC-entry object + * will release later by RCU. + */ +static int avc_update_node(u32 event, u32 perms, u8 driver, u8 base_perm, + u8 xperm, u32 ssid, u32 tsid, u16 tclass, u32 seqno, + struct extended_perms_decision *xpd, u32 flags) +{ + u32 hvalue; + int rc = 0; + unsigned long flag; + struct avc_node *pos, *node, *orig = NULL; + struct hlist_head *head; + spinlock_t *lock; + + node = avc_alloc_node(); + if (!node) { + rc = -ENOMEM; + goto out; + } + + /* Lock the target slot */ + hvalue = avc_hash(ssid, tsid, tclass); + + head = &selinux_avc.avc_cache.slots[hvalue]; + lock = &selinux_avc.avc_cache.slots_lock[hvalue]; + + spin_lock_irqsave(lock, flag); + + hlist_for_each_entry(pos, head, list) { + if (ssid == pos->ae.ssid && + tsid == pos->ae.tsid && + tclass == pos->ae.tclass && + seqno == pos->ae.avd.seqno){ + orig = pos; + break; + } + } + + if (!orig) { + rc = -ENOENT; + avc_node_kill(node); + goto out_unlock; + } + + /* + * Copy and replace original node. + */ + + avc_node_populate(node, ssid, tsid, tclass, &orig->ae.avd); + + if (orig->ae.xp_node) { + rc = avc_xperms_populate(node, orig->ae.xp_node); + if (rc) { + avc_node_kill(node); + goto out_unlock; + } + } + + switch (event) { + case AVC_CALLBACK_GRANT: + node->ae.avd.allowed |= perms; + if (node->ae.xp_node && (flags & AVC_EXTENDED_PERMS)) + avc_xperms_allow_perm(node->ae.xp_node, driver, base_perm, xperm); + break; + case AVC_CALLBACK_TRY_REVOKE: + case AVC_CALLBACK_REVOKE: + node->ae.avd.allowed &= ~perms; + break; + case AVC_CALLBACK_AUDITALLOW_ENABLE: + node->ae.avd.auditallow |= perms; + break; + case AVC_CALLBACK_AUDITALLOW_DISABLE: + node->ae.avd.auditallow &= ~perms; + break; + case AVC_CALLBACK_AUDITDENY_ENABLE: + node->ae.avd.auditdeny |= perms; + break; + case AVC_CALLBACK_AUDITDENY_DISABLE: + node->ae.avd.auditdeny &= ~perms; + break; + case AVC_CALLBACK_ADD_XPERMS: + rc = avc_add_xperms_decision(node, xpd); + if (rc) { + avc_node_kill(node); + goto out_unlock; + } + break; + } + avc_node_replace(node, orig); +out_unlock: + spin_unlock_irqrestore(lock, flag); +out: + return rc; +} + +/** + * avc_flush - Flush the cache + */ +static void avc_flush(void) +{ + struct hlist_head *head; + struct avc_node *node; + spinlock_t *lock; + unsigned long flag; + int i; + + for (i = 0; i < AVC_CACHE_SLOTS; i++) { + head = &selinux_avc.avc_cache.slots[i]; + lock = &selinux_avc.avc_cache.slots_lock[i]; + + spin_lock_irqsave(lock, flag); + /* + * With preemptible RCU, the outer spinlock does not + * prevent RCU grace periods from ending. + */ + rcu_read_lock(); + hlist_for_each_entry(node, head, list) + avc_node_delete(node); + rcu_read_unlock(); + spin_unlock_irqrestore(lock, flag); + } +} + +/** + * avc_ss_reset - Flush the cache and revalidate migrated permissions. + * @seqno: policy sequence number + */ +int avc_ss_reset(u32 seqno) +{ + struct avc_callback_node *c; + int rc = 0, tmprc; + + avc_flush(); + + for (c = avc_callbacks; c; c = c->next) { + if (c->events & AVC_CALLBACK_RESET) { + tmprc = c->callback(AVC_CALLBACK_RESET); + /* save the first error encountered for the return + value and continue processing the callbacks */ + if (!rc) + rc = tmprc; + } + } + + avc_latest_notif_update(seqno, 0); + return rc; +} + +/** + * avc_compute_av - Add an entry to the AVC based on the security policy + * @ssid: subject + * @tsid: object/target + * @tclass: object class + * @avd: access vector decision + * @xp_node: AVC extended permissions node + * + * Slow-path helper function for avc_has_perm_noaudit, when the avc_node lookup + * fails. Don't inline this, since it's the slow-path and just results in a + * bigger stack frame. + */ +static noinline void avc_compute_av(u32 ssid, u32 tsid, u16 tclass, + struct av_decision *avd, + struct avc_xperms_node *xp_node) +{ + INIT_LIST_HEAD(&xp_node->xpd_head); + security_compute_av(ssid, tsid, tclass, avd, &xp_node->xp); + avc_insert(ssid, tsid, tclass, avd, xp_node); +} + +static noinline int avc_denied(u32 ssid, u32 tsid, u16 tclass, u32 requested, + u8 driver, u8 base_perm, u8 xperm, + unsigned int flags, struct av_decision *avd) +{ + if (flags & AVC_STRICT) + return -EACCES; + + if (enforcing_enabled() && + !(avd->flags & AVD_FLAGS_PERMISSIVE)) + return -EACCES; + + avc_update_node(AVC_CALLBACK_GRANT, requested, driver, base_perm, + xperm, ssid, tsid, tclass, avd->seqno, NULL, flags); + return 0; +} + +/* + * The avc extended permissions logic adds an additional 256 bits of + * permissions to an avc node when extended permissions for that node are + * specified in the avtab. If the additional 256 permissions is not adequate, + * as-is the case with ioctls, then multiple may be chained together and the + * driver field is used to specify which set contains the permission. + */ +int avc_has_extended_perms(u32 ssid, u32 tsid, u16 tclass, u32 requested, + u8 driver, u8 base_perm, u8 xperm, + struct common_audit_data *ad) +{ + struct avc_node *node; + struct av_decision avd; + u32 denied; + struct extended_perms_decision local_xpd; + struct extended_perms_decision *xpd = NULL; + struct extended_perms_data allowed; + struct extended_perms_data auditallow; + struct extended_perms_data dontaudit; + struct avc_xperms_node local_xp_node; + struct avc_xperms_node *xp_node; + int rc = 0, rc2; + + xp_node = &local_xp_node; + if (WARN_ON(!requested)) + return -EACCES; + + rcu_read_lock(); + + node = avc_lookup(ssid, tsid, tclass); + if (unlikely(!node)) { + avc_compute_av(ssid, tsid, tclass, &avd, xp_node); + } else { + memcpy(&avd, &node->ae.avd, sizeof(avd)); + xp_node = node->ae.xp_node; + } + /* if extended permissions are not defined, only consider av_decision */ + if (!xp_node || !xp_node->xp.len) + goto decision; + + local_xpd.allowed = &allowed; + local_xpd.auditallow = &auditallow; + local_xpd.dontaudit = &dontaudit; + + xpd = avc_xperms_decision_lookup(driver, base_perm, xp_node); + if (unlikely(!xpd)) { + /* + * Compute the extended_perms_decision only if the driver + * is flagged and the base permission is known. + */ + if (!security_xperm_test(xp_node->xp.drivers.p, driver) || + !(xp_node->xp.base_perms & base_perm)) { + avd.allowed &= ~requested; + goto decision; + } + rcu_read_unlock(); + security_compute_xperms_decision(ssid, tsid, tclass, driver, + base_perm, &local_xpd); + rcu_read_lock(); + avc_update_node(AVC_CALLBACK_ADD_XPERMS, requested, driver, + base_perm, xperm, ssid, tsid, tclass, avd.seqno, + &local_xpd, 0); + } else { + avc_quick_copy_xperms_decision(xperm, &local_xpd, xpd); + } + xpd = &local_xpd; + + if (!avc_xperms_has_perm(xpd, xperm, XPERMS_ALLOWED)) + avd.allowed &= ~requested; + +decision: + denied = requested & ~(avd.allowed); + if (unlikely(denied)) + rc = avc_denied(ssid, tsid, tclass, requested, driver, + base_perm, xperm, AVC_EXTENDED_PERMS, &avd); + + rcu_read_unlock(); + + rc2 = avc_xperms_audit(ssid, tsid, tclass, requested, + &avd, xpd, xperm, rc, ad); + if (rc2) + return rc2; + return rc; +} + +/** + * avc_perm_nonode - Add an entry to the AVC + * @ssid: subject + * @tsid: object/target + * @tclass: object class + * @requested: requested permissions + * @flags: AVC flags + * @avd: access vector decision + * + * This is the "we have no node" part of avc_has_perm_noaudit(), which is + * unlikely and needs extra stack space for the new node that we generate, so + * don't inline it. + */ +static noinline int avc_perm_nonode(u32 ssid, u32 tsid, u16 tclass, + u32 requested, unsigned int flags, + struct av_decision *avd) +{ + u32 denied; + struct avc_xperms_node xp_node; + + avc_compute_av(ssid, tsid, tclass, avd, &xp_node); + denied = requested & ~(avd->allowed); + if (unlikely(denied)) + return avc_denied(ssid, tsid, tclass, requested, 0, 0, 0, + flags, avd); + return 0; +} + +/** + * avc_has_perm_noaudit - Check permissions but perform no auditing. + * @ssid: source security identifier + * @tsid: target security identifier + * @tclass: target security class + * @requested: requested permissions, interpreted based on @tclass + * @flags: AVC_STRICT or 0 + * @avd: access vector decisions + * + * Check the AVC to determine whether the @requested permissions are granted + * for the SID pair (@ssid, @tsid), interpreting the permissions + * based on @tclass, and call the security server on a cache miss to obtain + * a new decision and add it to the cache. Return a copy of the decisions + * in @avd. Return %0 if all @requested permissions are granted, + * -%EACCES if any permissions are denied, or another -errno upon + * other errors. This function is typically called by avc_has_perm(), + * but may also be called directly to separate permission checking from + * auditing, e.g. in cases where a lock must be held for the check but + * should be released for the auditing. + */ +inline int avc_has_perm_noaudit(u32 ssid, u32 tsid, + u16 tclass, u32 requested, + unsigned int flags, + struct av_decision *avd) +{ + u32 denied; + struct avc_node *node; + + if (WARN_ON(!requested)) + return -EACCES; + + rcu_read_lock(); + node = avc_lookup(ssid, tsid, tclass); + if (unlikely(!node)) { + rcu_read_unlock(); + return avc_perm_nonode(ssid, tsid, tclass, requested, + flags, avd); + } + denied = requested & ~node->ae.avd.allowed; + memcpy(avd, &node->ae.avd, sizeof(*avd)); + rcu_read_unlock(); + + if (unlikely(denied)) + return avc_denied(ssid, tsid, tclass, requested, 0, 0, 0, + flags, avd); + return 0; +} + +/** + * avc_has_perm - Check permissions and perform any appropriate auditing. + * @ssid: source security identifier + * @tsid: target security identifier + * @tclass: target security class + * @requested: requested permissions, interpreted based on @tclass + * @auditdata: auxiliary audit data + * + * Check the AVC to determine whether the @requested permissions are granted + * for the SID pair (@ssid, @tsid), interpreting the permissions + * based on @tclass, and call the security server on a cache miss to obtain + * a new decision and add it to the cache. Audit the granting or denial of + * permissions in accordance with the policy. Return %0 if all @requested + * permissions are granted, -%EACCES if any permissions are denied, or + * another -errno upon other errors. + */ +int avc_has_perm(u32 ssid, u32 tsid, u16 tclass, + u32 requested, struct common_audit_data *auditdata) +{ + struct av_decision avd; + int rc, rc2; + + rc = avc_has_perm_noaudit(ssid, tsid, tclass, requested, 0, + &avd); + + rc2 = avc_audit(ssid, tsid, tclass, requested, &avd, rc, + auditdata); + if (rc2) + return rc2; + return rc; +} + +u32 avc_policy_seqno(void) +{ + return selinux_avc.avc_cache.latest_notif; +} diff --git a/security/selinux/genheaders.c b/security/selinux/genheaders.c new file mode 100644 index 000000000..3834d7eb0 --- /dev/null +++ b/security/selinux/genheaders.c @@ -0,0 +1,154 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> +#include <string.h> +#include <errno.h> +#include <ctype.h> + +struct security_class_mapping { + const char *name; + const char *perms[sizeof(unsigned) * 8 + 1]; +}; + +#include "classmap.h" +#include "initial_sid_to_string.h" + +const char *progname; + +static void usage(void) +{ + printf("usage: %s flask.h av_permissions.h\n", progname); + exit(1); +} + +static char *stoupperx(const char *s) +{ + char *s2 = strdup(s); + char *p; + + if (!s2) { + fprintf(stderr, "%s: out of memory\n", progname); + exit(3); + } + + for (p = s2; *p; p++) + *p = toupper(*p); + return s2; +} + +int main(int argc, char *argv[]) +{ + int i, j; + int isids_len; + FILE *fout; + + progname = argv[0]; + + if (argc < 3) + usage(); + + fout = fopen(argv[1], "w"); + if (!fout) { + fprintf(stderr, "Could not open %s for writing: %s\n", + argv[1], strerror(errno)); + exit(2); + } + + fprintf(fout, "/* This file is automatically generated. Do not edit. */\n"); + fprintf(fout, "#ifndef _SELINUX_FLASK_H_\n#define _SELINUX_FLASK_H_\n\n"); + + for (i = 0; secclass_map[i].name; i++) { + char *name = stoupperx(secclass_map[i].name); + + fprintf(fout, "#define SECCLASS_%-39s %2d\n", name, i+1); + free(name); + } + + fprintf(fout, "\n"); + + isids_len = sizeof(initial_sid_to_string) / sizeof(char *); + for (i = 1; i < isids_len; i++) { + const char *s = initial_sid_to_string[i]; + if (s) { + char *sidname = stoupperx(s); + + fprintf(fout, "#define SECINITSID_%-39s %2d\n", sidname, i); + free(sidname); + } + } + fprintf(fout, "\n#define SECINITSID_NUM %d\n", i-1); + fprintf(fout, "\nstatic inline bool security_is_socket_class(u16 kern_tclass)\n"); + fprintf(fout, "{\n"); + fprintf(fout, "\tbool sock = false;\n\n"); + fprintf(fout, "\tswitch (kern_tclass) {\n"); + for (i = 0; secclass_map[i].name; i++) { + static char s[] = "SOCKET"; + int len, l; + char *name = stoupperx(secclass_map[i].name); + + len = strlen(name); + l = sizeof(s) - 1; + if (len >= l && memcmp(name + len - l, s, l) == 0) + fprintf(fout, "\tcase SECCLASS_%s:\n", name); + free(name); + } + fprintf(fout, "\t\tsock = true;\n"); + fprintf(fout, "\t\tbreak;\n"); + fprintf(fout, "\tdefault:\n"); + fprintf(fout, "\t\tbreak;\n"); + fprintf(fout, "\t}\n\n"); + fprintf(fout, "\treturn sock;\n"); + fprintf(fout, "}\n"); + + fprintf(fout, "\n#endif\n"); + + if (fclose(fout) != 0) { + fprintf(stderr, "Could not successfully close %s: %s\n", + argv[1], strerror(errno)); + exit(4); + } + + fout = fopen(argv[2], "w"); + if (!fout) { + fprintf(stderr, "Could not open %s for writing: %s\n", + argv[2], strerror(errno)); + exit(5); + } + + fprintf(fout, "/* This file is automatically generated. Do not edit. */\n"); + fprintf(fout, "#ifndef _SELINUX_AV_PERMISSIONS_H_\n#define _SELINUX_AV_PERMISSIONS_H_\n\n"); + + for (i = 0; secclass_map[i].name; i++) { + const struct security_class_mapping *map = &secclass_map[i]; + int len; + char *name = stoupperx(map->name); + + len = strlen(name); + for (j = 0; map->perms[j]; j++) { + char *permname; + + if (j >= 32) { + fprintf(stderr, "Too many permissions to fit into an access vector at (%s, %s).\n", + map->name, map->perms[j]); + exit(5); + } + permname = stoupperx(map->perms[j]); + fprintf(fout, "#define %s__%-*s 0x%08xU\n", name, + 39-len, permname, 1U<<j); + free(permname); + } + free(name); + } + + fprintf(fout, "\n#endif\n"); + + if (fclose(fout) != 0) { + fprintf(stderr, "Could not successfully close %s: %s\n", + argv[2], strerror(errno)); + exit(6); + } + + exit(0); +} diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c new file mode 100644 index 000000000..035aaf113 --- /dev/null +++ b/security/selinux/hooks.c @@ -0,0 +1,8008 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Security-Enhanced Linux (SELinux) security module + * + * This file contains the SELinux hook function implementations. + * + * Authors: Stephen Smalley, <stephen.smalley.work@gmail.com> + * Chris Vance, <cvance@nai.com> + * Wayne Salamon, <wsalamon@nai.com> + * James Morris <jmorris@redhat.com> + * + * Copyright (C) 2001,2002 Networks Associates Technology, Inc. + * Copyright (C) 2003-2008 Red Hat, Inc., James Morris <jmorris@redhat.com> + * Eric Paris <eparis@redhat.com> + * Copyright (C) 2004-2005 Trusted Computer Solutions, Inc. + * <dgoeddel@trustedcs.com> + * Copyright (C) 2006, 2007, 2009 Hewlett-Packard Development Company, L.P. + * Paul Moore <paul@paul-moore.com> + * Copyright (C) 2007 Hitachi Software Engineering Co., Ltd. + * Yuichi Nakamura <ynakam@hitachisoft.jp> + * Copyright (C) 2016 Mellanox Technologies + */ + +#include <linux/init.h> +#include <linux/kd.h> +#include <linux/kernel.h> +#include <linux/kernel_read_file.h> +#include <linux/errno.h> +#include <linux/sched/signal.h> +#include <linux/sched/task.h> +#include <linux/lsm_hooks.h> +#include <linux/xattr.h> +#include <linux/capability.h> +#include <linux/unistd.h> +#include <linux/mm.h> +#include <linux/mman.h> +#include <linux/slab.h> +#include <linux/pagemap.h> +#include <linux/proc_fs.h> +#include <linux/swap.h> +#include <linux/spinlock.h> +#include <linux/syscalls.h> +#include <linux/dcache.h> +#include <linux/file.h> +#include <linux/fdtable.h> +#include <linux/namei.h> +#include <linux/mount.h> +#include <linux/fs_context.h> +#include <linux/fs_parser.h> +#include <linux/netfilter_ipv4.h> +#include <linux/netfilter_ipv6.h> +#include <linux/tty.h> +#include <net/icmp.h> +#include <net/ip.h> /* for local_port_range[] */ +#include <net/tcp.h> /* struct or_callable used in sock_rcv_skb */ +#include <net/inet_connection_sock.h> +#include <net/net_namespace.h> +#include <net/netlabel.h> +#include <linux/uaccess.h> +#include <asm/ioctls.h> +#include <linux/atomic.h> +#include <linux/bitops.h> +#include <linux/interrupt.h> +#include <linux/netdevice.h> /* for network interface checks */ +#include <net/netlink.h> +#include <linux/tcp.h> +#include <linux/udp.h> +#include <linux/sctp.h> +#include <net/sctp/structs.h> +#include <linux/quota.h> +#include <linux/un.h> /* for Unix socket types */ +#include <net/af_unix.h> /* for Unix socket types */ +#include <linux/parser.h> +#include <linux/nfs_mount.h> +#include <net/ipv6.h> +#include <linux/hugetlb.h> +#include <linux/personality.h> +#include <linux/audit.h> +#include <linux/string.h> +#include <linux/mutex.h> +#include <linux/posix-timers.h> +#include <linux/syslog.h> +#include <linux/user_namespace.h> +#include <linux/export.h> +#include <linux/msg.h> +#include <linux/shm.h> +#include <uapi/linux/shm.h> +#include <linux/bpf.h> +#include <linux/kernfs.h> +#include <linux/stringhash.h> /* for hashlen_string() */ +#include <uapi/linux/mount.h> +#include <linux/fsnotify.h> +#include <linux/fanotify.h> +#include <linux/io_uring/cmd.h> +#include <uapi/linux/lsm.h> +#include <linux/memfd.h> +#include <uapi/linux/inet_diag.h> + +#include "initcalls.h" +#include "avc.h" +#include "objsec.h" +#include "netif.h" +#include "netnode.h" +#include "netport.h" +#include "ibpkey.h" +#include "xfrm.h" +#include "netlabel.h" +#include "audit.h" +#include "avc_ss.h" +#include "ima.h" + +#define SELINUX_INODE_INIT_XATTRS 1 + +struct selinux_state selinux_state; + +/* SECMARK reference count */ +static atomic_t selinux_secmark_refcount = ATOMIC_INIT(0); + +#ifdef CONFIG_SECURITY_SELINUX_DEVELOP +static int selinux_enforcing_boot __initdata; + +static int __init enforcing_setup(char *str) +{ + unsigned long enforcing; + if (!kstrtoul(str, 0, &enforcing)) + selinux_enforcing_boot = enforcing ? 1 : 0; + return 1; +} +__setup("enforcing=", enforcing_setup); +#else +#define selinux_enforcing_boot 1 +#endif + +int selinux_enabled_boot __initdata = 1; +#ifdef CONFIG_SECURITY_SELINUX_BOOTPARAM +static int __init selinux_enabled_setup(char *str) +{ + unsigned long enabled; + if (!kstrtoul(str, 0, &enabled)) + selinux_enabled_boot = enabled ? 1 : 0; + return 1; +} +__setup("selinux=", selinux_enabled_setup); +#endif + +static int __init checkreqprot_setup(char *str) +{ + unsigned long checkreqprot; + + if (!kstrtoul(str, 0, &checkreqprot)) { + if (checkreqprot) + pr_err("SELinux: checkreqprot set to 1 via kernel parameter. This is no longer supported.\n"); + } + return 1; +} +__setup("checkreqprot=", checkreqprot_setup); + +/** + * selinux_secmark_enabled - Check to see if SECMARK is currently enabled + * + * Description: + * This function checks the SECMARK reference counter to see if any SECMARK + * targets are currently configured, if the reference counter is greater than + * zero SECMARK is considered to be enabled. Returns true (1) if SECMARK is + * enabled, false (0) if SECMARK is disabled. If the always_check_network + * policy capability is enabled, SECMARK is always considered enabled. + * + */ +static int selinux_secmark_enabled(void) +{ + return (selinux_policycap_alwaysnetwork() || + atomic_read(&selinux_secmark_refcount)); +} + +/** + * selinux_peerlbl_enabled - Check to see if peer labeling is currently enabled + * + * Description: + * This function checks if NetLabel or labeled IPSEC is enabled. Returns true + * (1) if any are enabled or false (0) if neither are enabled. If the + * always_check_network policy capability is enabled, peer labeling + * is always considered enabled. + * + */ +static int selinux_peerlbl_enabled(void) +{ + return (selinux_policycap_alwaysnetwork() || + netlbl_enabled() || selinux_xfrm_enabled()); +} + +static int selinux_netcache_avc_callback(u32 event) +{ + if (event == AVC_CALLBACK_RESET) { + sel_netif_flush(); + sel_netnode_flush(); + sel_netport_flush(); + synchronize_net(); + } + return 0; +} + +static int selinux_lsm_notifier_avc_callback(u32 event) +{ + if (event == AVC_CALLBACK_RESET) { + sel_ib_pkey_flush(); + call_blocking_lsm_notifier(LSM_POLICY_CHANGE, NULL); + } + + return 0; +} + +/* + * initialise the security for the init task + */ +static void cred_init_security(void) +{ + struct cred_security_struct *crsec; + + /* NOTE: the lsm framework zeros out the buffer on allocation */ + + crsec = selinux_cred(unrcu_pointer(current->real_cred)); + crsec->osid = crsec->sid = SECINITSID_KERNEL; +} + +/* + * get the security ID of a set of credentials + */ +static inline u32 cred_sid(const struct cred *cred) +{ + const struct cred_security_struct *crsec; + + crsec = selinux_cred(cred); + return crsec->sid; +} + +static void __ad_net_init(struct common_audit_data *ad, + struct lsm_network_audit *net, + int ifindex, struct sock *sk, u16 family) +{ + ad->type = LSM_AUDIT_DATA_NET; + ad->u.net = net; + net->netif = ifindex; + net->sk = sk; + net->family = family; +} + +static void ad_net_init_from_sk(struct common_audit_data *ad, + struct lsm_network_audit *net, + struct sock *sk) +{ + __ad_net_init(ad, net, 0, sk, 0); +} + +static void ad_net_init_from_iif(struct common_audit_data *ad, + struct lsm_network_audit *net, + int ifindex, u16 family) +{ + __ad_net_init(ad, net, ifindex, NULL, family); +} + +/* + * get the objective security ID of a task + */ +static inline u32 task_sid_obj(const struct task_struct *task) +{ + u32 sid; + + rcu_read_lock(); + sid = cred_sid(__task_cred(task)); + rcu_read_unlock(); + return sid; +} + +static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry); + +/* + * Try reloading inode security labels that have been marked as invalid. The + * @may_sleep parameter indicates when sleeping and thus reloading labels is + * allowed; when set to false, returns -ECHILD when the label is + * invalid. The @dentry parameter should be set to a dentry of the inode. + */ +static int __inode_security_revalidate(struct inode *inode, + struct dentry *dentry, + bool may_sleep) +{ + if (!selinux_initialized()) + return 0; + + if (may_sleep) + might_sleep(); + else + return -ECHILD; + + /* + * Check to ensure that an inode's SELinux state is valid and try + * reloading the inode security label if necessary. This will fail if + * @dentry is NULL and no dentry for this inode can be found; in that + * case, continue using the old label. + */ + inode_doinit_with_dentry(inode, dentry); + return 0; +} + +static struct inode_security_struct *inode_security_novalidate(struct inode *inode) +{ + return selinux_inode(inode); +} + +static inline struct inode_security_struct *inode_security_rcu(struct inode *inode, + bool rcu) +{ + int rc; + struct inode_security_struct *isec = selinux_inode(inode); + + /* check below is racy, but revalidate will recheck with lock held */ + if (data_race(likely(isec->initialized == LABEL_INITIALIZED))) + return isec; + rc = __inode_security_revalidate(inode, NULL, !rcu); + if (rc) + return ERR_PTR(rc); + return isec; +} + +/* + * Get the security label of an inode. + */ +static inline struct inode_security_struct *inode_security(struct inode *inode) +{ + struct inode_security_struct *isec = selinux_inode(inode); + + /* check below is racy, but revalidate will recheck with lock held */ + if (data_race(likely(isec->initialized == LABEL_INITIALIZED))) + return isec; + __inode_security_revalidate(inode, NULL, true); + return isec; +} + +static inline struct inode_security_struct *backing_inode_security_novalidate(struct dentry *dentry) +{ + return selinux_inode(d_backing_inode(dentry)); +} + +/* + * Get the security label of a dentry's backing inode. + */ +static inline struct inode_security_struct *backing_inode_security(struct dentry *dentry) +{ + struct inode *inode = d_backing_inode(dentry); + struct inode_security_struct *isec = selinux_inode(inode); + + /* check below is racy, but revalidate will recheck with lock held */ + if (data_race(likely(isec->initialized == LABEL_INITIALIZED))) + return isec; + __inode_security_revalidate(inode, dentry, true); + return isec; +} + +static void inode_free_security(struct inode *inode) +{ + struct inode_security_struct *isec = selinux_inode(inode); + struct superblock_security_struct *sbsec; + + if (!isec) + return; + sbsec = selinux_superblock(inode->i_sb); + /* + * As not all inode security structures are in a list, we check for + * empty list outside of the lock to make sure that we won't waste + * time taking a lock doing nothing. + * + * The list_del_init() function can be safely called more than once. + * It should not be possible for this function to be called with + * concurrent list_add(), but for better safety against future changes + * in the code, we use list_empty_careful() here. + */ + if (!list_empty_careful(&isec->list)) { + spin_lock(&sbsec->isec_lock); + list_del_init(&isec->list); + spin_unlock(&sbsec->isec_lock); + } +} + +struct selinux_mnt_opts { + u32 fscontext_sid; + u32 context_sid; + u32 rootcontext_sid; + u32 defcontext_sid; +}; + +static void selinux_free_mnt_opts(void *mnt_opts) +{ + kfree(mnt_opts); +} + +enum { + Opt_error = -1, + Opt_context = 0, + Opt_defcontext = 1, + Opt_fscontext = 2, + Opt_rootcontext = 3, + Opt_seclabel = 4, +}; + +#define A(s, has_arg) {#s, sizeof(#s) - 1, Opt_##s, has_arg} +static const struct { + const char *name; + int len; + int opt; + bool has_arg; +} tokens[] = { + A(context, true), + A(fscontext, true), + A(defcontext, true), + A(rootcontext, true), + A(seclabel, false), +}; +#undef A + +static int match_opt_prefix(char *s, int l, char **arg) +{ + unsigned int i; + + for (i = 0; i < ARRAY_SIZE(tokens); i++) { + size_t len = tokens[i].len; + if (len > l || memcmp(s, tokens[i].name, len)) + continue; + if (tokens[i].has_arg) { + if (len == l || s[len] != '=') + continue; + *arg = s + len + 1; + } else if (len != l) + continue; + return tokens[i].opt; + } + return Opt_error; +} + +#define SEL_MOUNT_FAIL_MSG "SELinux: duplicate or incompatible mount options\n" + +static int may_context_mount_sb_relabel(u32 sid, + struct superblock_security_struct *sbsec, + const struct cred *cred) +{ + const struct cred_security_struct *crsec = selinux_cred(cred); + int rc; + + rc = avc_has_perm(crsec->sid, sbsec->sid, SECCLASS_FILESYSTEM, + FILESYSTEM__RELABELFROM, NULL); + if (rc) + return rc; + + rc = avc_has_perm(crsec->sid, sid, SECCLASS_FILESYSTEM, + FILESYSTEM__RELABELTO, NULL); + return rc; +} + +static int may_context_mount_inode_relabel(u32 sid, + struct superblock_security_struct *sbsec, + const struct cred *cred) +{ + const struct cred_security_struct *crsec = selinux_cred(cred); + int rc; + rc = avc_has_perm(crsec->sid, sbsec->sid, SECCLASS_FILESYSTEM, + FILESYSTEM__RELABELFROM, NULL); + if (rc) + return rc; + + rc = avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM, + FILESYSTEM__ASSOCIATE, NULL); + return rc; +} + +static int selinux_is_genfs_special_handling(struct super_block *sb) +{ + /* Special handling. Genfs but also in-core setxattr handler */ + return !strcmp(sb->s_type->name, "sysfs") || + !strcmp(sb->s_type->name, "pstore") || + !strcmp(sb->s_type->name, "debugfs") || + !strcmp(sb->s_type->name, "tracefs") || + !strcmp(sb->s_type->name, "rootfs") || + (selinux_policycap_cgroupseclabel() && + (!strcmp(sb->s_type->name, "cgroup") || + !strcmp(sb->s_type->name, "cgroup2"))) || + (selinux_policycap_functionfs_seclabel() && + !strcmp(sb->s_type->name, "functionfs")); +} + +static int selinux_is_sblabel_mnt(struct super_block *sb) +{ + struct superblock_security_struct *sbsec = selinux_superblock(sb); + + /* + * IMPORTANT: Double-check logic in this function when adding a new + * SECURITY_FS_USE_* definition! + */ + BUILD_BUG_ON(SECURITY_FS_USE_MAX != 7); + + switch (sbsec->behavior) { + case SECURITY_FS_USE_XATTR: + case SECURITY_FS_USE_TRANS: + case SECURITY_FS_USE_TASK: + case SECURITY_FS_USE_NATIVE: + return 1; + + case SECURITY_FS_USE_GENFS: + return selinux_is_genfs_special_handling(sb); + + /* Never allow relabeling on context mounts */ + case SECURITY_FS_USE_MNTPOINT: + case SECURITY_FS_USE_NONE: + default: + return 0; + } +} + +static int sb_check_xattr_support(struct super_block *sb) +{ + struct superblock_security_struct *sbsec = selinux_superblock(sb); + struct dentry *root = sb->s_root; + struct inode *root_inode = d_backing_inode(root); + u32 sid; + int rc; + + /* + * Make sure that the xattr handler exists and that no + * error other than -ENODATA is returned by getxattr on + * the root directory. -ENODATA is ok, as this may be + * the first boot of the SELinux kernel before we have + * assigned xattr values to the filesystem. + */ + if (!(root_inode->i_opflags & IOP_XATTR)) { + pr_warn("SELinux: (dev %s, type %s) has no xattr support\n", + sb->s_id, sb->s_type->name); + goto fallback; + } + + rc = __vfs_getxattr(root, root_inode, XATTR_NAME_SELINUX, NULL, 0); + if (rc < 0 && rc != -ENODATA) { + if (rc == -EOPNOTSUPP) { + pr_warn("SELinux: (dev %s, type %s) has no security xattr handler\n", + sb->s_id, sb->s_type->name); + goto fallback; + } else { + pr_warn("SELinux: (dev %s, type %s) getxattr errno %d\n", + sb->s_id, sb->s_type->name, -rc); + return rc; + } + } + return 0; + +fallback: + /* No xattr support - try to fallback to genfs if possible. */ + rc = security_genfs_sid(sb->s_type->name, "/", + SECCLASS_DIR, &sid); + if (rc) + return -EOPNOTSUPP; + + pr_warn("SELinux: (dev %s, type %s) falling back to genfs\n", + sb->s_id, sb->s_type->name); + sbsec->behavior = SECURITY_FS_USE_GENFS; + sbsec->sid = sid; + return 0; +} + +static int sb_finish_set_opts(struct super_block *sb) +{ + struct superblock_security_struct *sbsec = selinux_superblock(sb); + struct dentry *root = sb->s_root; + struct inode *root_inode = d_backing_inode(root); + int rc = 0; + + if (sbsec->behavior == SECURITY_FS_USE_XATTR) { + rc = sb_check_xattr_support(sb); + if (rc) + return rc; + } + + sbsec->flags |= SE_SBINITIALIZED; + + /* + * Explicitly set or clear SBLABEL_MNT. It's not sufficient to simply + * leave the flag untouched because sb_clone_mnt_opts might be handing + * us a superblock that needs the flag to be cleared. + */ + if (selinux_is_sblabel_mnt(sb)) + sbsec->flags |= SBLABEL_MNT; + else + sbsec->flags &= ~SBLABEL_MNT; + + /* Initialize the root inode. */ + rc = inode_doinit_with_dentry(root_inode, root); + + /* Initialize any other inodes associated with the superblock, e.g. + inodes created prior to initial policy load or inodes created + during get_sb by a pseudo filesystem that directly + populates itself. */ + spin_lock(&sbsec->isec_lock); + while (!list_empty(&sbsec->isec_head)) { + struct inode_security_struct *isec = + list_first_entry(&sbsec->isec_head, + struct inode_security_struct, list); + struct inode *inode = isec->inode; + list_del_init(&isec->list); + spin_unlock(&sbsec->isec_lock); + inode = igrab(inode); + if (inode) { + if (!IS_PRIVATE(inode)) + inode_doinit_with_dentry(inode, NULL); + iput(inode); + } + spin_lock(&sbsec->isec_lock); + } + spin_unlock(&sbsec->isec_lock); + return rc; +} + +static int bad_option(struct superblock_security_struct *sbsec, char flag, + u32 old_sid, u32 new_sid) +{ + char mnt_flags = sbsec->flags & SE_MNTMASK; + + /* check if the old mount command had the same options */ + if (sbsec->flags & SE_SBINITIALIZED) + if (!(sbsec->flags & flag) || + (old_sid != new_sid)) + return 1; + + /* check if we were passed the same options twice, + * aka someone passed context=a,context=b + */ + if (!(sbsec->flags & SE_SBINITIALIZED)) + if (mnt_flags & flag) + return 1; + return 0; +} + +/* + * Allow filesystems with binary mount data to explicitly set mount point + * labeling information. + */ +static int selinux_set_mnt_opts(struct super_block *sb, + void *mnt_opts, + unsigned long kern_flags, + unsigned long *set_kern_flags) +{ + const struct cred *cred = current_cred(); + struct superblock_security_struct *sbsec = selinux_superblock(sb); + struct dentry *root = sb->s_root; + struct selinux_mnt_opts *opts = mnt_opts; + struct inode_security_struct *root_isec; + u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0; + u32 defcontext_sid = 0; + int rc = 0; + + /* + * Specifying internal flags without providing a place to + * place the results is not allowed + */ + if (kern_flags && !set_kern_flags) + return -EINVAL; + + mutex_lock(&sbsec->lock); + + if (!selinux_initialized()) { + if (!opts) { + /* Defer initialization until selinux_complete_init, + after the initial policy is loaded and the security + server is ready to handle calls. */ + if (kern_flags & SECURITY_LSM_NATIVE_LABELS) { + sbsec->flags |= SE_SBNATIVE; + *set_kern_flags |= SECURITY_LSM_NATIVE_LABELS; + } + goto out; + } + rc = -EINVAL; + pr_warn("SELinux: Unable to set superblock options " + "before the security server is initialized\n"); + goto out; + } + + /* + * Binary mount data FS will come through this function twice. Once + * from an explicit call and once from the generic calls from the vfs. + * Since the generic VFS calls will not contain any security mount data + * we need to skip the double mount verification. + * + * This does open a hole in which we will not notice if the first + * mount using this sb set explicit options and a second mount using + * this sb does not set any security options. (The first options + * will be used for both mounts) + */ + if ((sbsec->flags & SE_SBINITIALIZED) && (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA) + && !opts) + goto out; + + root_isec = backing_inode_security_novalidate(root); + + /* + * parse the mount options, check if they are valid sids. + * also check if someone is trying to mount the same sb more + * than once with different security options. + */ + if (opts) { + if (opts->fscontext_sid) { + fscontext_sid = opts->fscontext_sid; + if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid, + fscontext_sid)) + goto out_double_mount; + sbsec->flags |= FSCONTEXT_MNT; + } + if (opts->context_sid) { + context_sid = opts->context_sid; + if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid, + context_sid)) + goto out_double_mount; + sbsec->flags |= CONTEXT_MNT; + } + if (opts->rootcontext_sid) { + rootcontext_sid = opts->rootcontext_sid; + if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid, + rootcontext_sid)) + goto out_double_mount; + sbsec->flags |= ROOTCONTEXT_MNT; + } + if (opts->defcontext_sid) { + defcontext_sid = opts->defcontext_sid; + if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid, + defcontext_sid)) + goto out_double_mount; + sbsec->flags |= DEFCONTEXT_MNT; + } + } + + if (sbsec->flags & SE_SBINITIALIZED) { + /* previously mounted with options, but not on this attempt? */ + if ((sbsec->flags & SE_MNTMASK) && !opts) + goto out_double_mount; + rc = 0; + goto out; + } + + sbsec->creator_sid = current_sid(); + + if (strcmp(sb->s_type->name, "proc") == 0) + sbsec->flags |= SE_SBPROC | SE_SBGENFS; + + if (!strcmp(sb->s_type->name, "debugfs") || + !strcmp(sb->s_type->name, "tracefs") || + !strcmp(sb->s_type->name, "binder") || + !strcmp(sb->s_type->name, "bpf") || + !strcmp(sb->s_type->name, "pstore") || + !strcmp(sb->s_type->name, "securityfs") || + (selinux_policycap_functionfs_seclabel() && + !strcmp(sb->s_type->name, "functionfs"))) + sbsec->flags |= SE_SBGENFS; + + if (!strcmp(sb->s_type->name, "sysfs") || + !strcmp(sb->s_type->name, "cgroup") || + !strcmp(sb->s_type->name, "cgroup2")) + sbsec->flags |= SE_SBGENFS | SE_SBGENFS_XATTR; + + if (!sbsec->behavior) { + /* + * Determine the labeling behavior to use for this + * filesystem type. + */ + rc = security_fs_use(sb); + if (rc) { + pr_warn("%s: security_fs_use(%s) returned %d\n", + __func__, sb->s_type->name, rc); + goto out; + } + } + + /* + * If this is a user namespace mount and the filesystem type is not + * explicitly whitelisted, then no contexts are allowed on the command + * line and security labels must be ignored. + */ + if (sb->s_user_ns != &init_user_ns && + strcmp(sb->s_type->name, "tmpfs") && + strcmp(sb->s_type->name, "ramfs") && + strcmp(sb->s_type->name, "devpts") && + strcmp(sb->s_type->name, "overlay")) { + if (context_sid || fscontext_sid || rootcontext_sid || + defcontext_sid) { + rc = -EACCES; + goto out; + } + if (sbsec->behavior == SECURITY_FS_USE_XATTR) { + sbsec->behavior = SECURITY_FS_USE_MNTPOINT; + rc = security_transition_sid(current_sid(), + current_sid(), + SECCLASS_FILE, NULL, + &sbsec->mntpoint_sid); + if (rc) + goto out; + } + goto out_set_opts; + } + + /* sets the context of the superblock for the fs being mounted. */ + if (fscontext_sid) { + rc = may_context_mount_sb_relabel(fscontext_sid, sbsec, cred); + if (rc) + goto out; + + sbsec->sid = fscontext_sid; + } + + /* + * Switch to using mount point labeling behavior. + * sets the label used on all file below the mountpoint, and will set + * the superblock context if not already set. + */ + if (sbsec->flags & SE_SBNATIVE) { + /* + * This means we are initializing a superblock that has been + * mounted before the SELinux was initialized and the + * filesystem requested native labeling. We had already + * returned SECURITY_LSM_NATIVE_LABELS in *set_kern_flags + * in the original mount attempt, so now we just need to set + * the SECURITY_FS_USE_NATIVE behavior. + */ + sbsec->behavior = SECURITY_FS_USE_NATIVE; + } else if (kern_flags & SECURITY_LSM_NATIVE_LABELS && !context_sid) { + sbsec->behavior = SECURITY_FS_USE_NATIVE; + *set_kern_flags |= SECURITY_LSM_NATIVE_LABELS; + } + + if (context_sid) { + if (!fscontext_sid) { + rc = may_context_mount_sb_relabel(context_sid, sbsec, + cred); + if (rc) + goto out; + sbsec->sid = context_sid; + } else { + rc = may_context_mount_inode_relabel(context_sid, sbsec, + cred); + if (rc) + goto out; + } + if (!rootcontext_sid) + rootcontext_sid = context_sid; + + sbsec->mntpoint_sid = context_sid; + sbsec->behavior = SECURITY_FS_USE_MNTPOINT; + } + + if (rootcontext_sid) { + rc = may_context_mount_inode_relabel(rootcontext_sid, sbsec, + cred); + if (rc) + goto out; + + root_isec->sid = rootcontext_sid; + root_isec->initialized = LABEL_INITIALIZED; + } + + if (defcontext_sid) { + if (sbsec->behavior != SECURITY_FS_USE_XATTR && + sbsec->behavior != SECURITY_FS_USE_NATIVE) { + rc = -EINVAL; + pr_warn("SELinux: defcontext option is " + "invalid for this filesystem type\n"); + goto out; + } + + if (defcontext_sid != sbsec->def_sid) { + rc = may_context_mount_inode_relabel(defcontext_sid, + sbsec, cred); + if (rc) + goto out; + } + + sbsec->def_sid = defcontext_sid; + } + +out_set_opts: + rc = sb_finish_set_opts(sb); +out: + mutex_unlock(&sbsec->lock); + return rc; +out_double_mount: + rc = -EINVAL; + pr_warn("SELinux: mount invalid. Same superblock, different " + "security settings for (dev %s, type %s)\n", sb->s_id, + sb->s_type->name); + goto out; +} + +static int selinux_cmp_sb_context(const struct super_block *oldsb, + const struct super_block *newsb) +{ + struct superblock_security_struct *old = selinux_superblock(oldsb); + struct superblock_security_struct *new = selinux_superblock(newsb); + char oldflags = old->flags & SE_MNTMASK; + char newflags = new->flags & SE_MNTMASK; + + if (oldflags != newflags) + goto mismatch; + if ((oldflags & FSCONTEXT_MNT) && old->sid != new->sid) + goto mismatch; + if ((oldflags & CONTEXT_MNT) && old->mntpoint_sid != new->mntpoint_sid) + goto mismatch; + if ((oldflags & DEFCONTEXT_MNT) && old->def_sid != new->def_sid) + goto mismatch; + if (oldflags & ROOTCONTEXT_MNT) { + struct inode_security_struct *oldroot = backing_inode_security(oldsb->s_root); + struct inode_security_struct *newroot = backing_inode_security(newsb->s_root); + if (oldroot->sid != newroot->sid) + goto mismatch; + } + if (old->creator_sid != new->creator_sid) + goto mismatch; + return 0; +mismatch: + pr_warn("SELinux: mount invalid. Same superblock, " + "different security settings for (dev %s, " + "type %s)\n", newsb->s_id, newsb->s_type->name); + return -EBUSY; +} + +static int selinux_sb_clone_mnt_opts(const struct super_block *oldsb, + struct super_block *newsb, + unsigned long kern_flags, + unsigned long *set_kern_flags) +{ + int rc = 0; + const struct superblock_security_struct *oldsbsec = + selinux_superblock(oldsb); + struct superblock_security_struct *newsbsec = selinux_superblock(newsb); + + int set_fscontext = (oldsbsec->flags & FSCONTEXT_MNT); + int set_context = (oldsbsec->flags & CONTEXT_MNT); + int set_rootcontext = (oldsbsec->flags & ROOTCONTEXT_MNT); + + /* + * Specifying internal flags without providing a place to + * place the results is not allowed. + */ + if (kern_flags && !set_kern_flags) + return -EINVAL; + + mutex_lock(&newsbsec->lock); + + /* + * if the parent was able to be mounted it clearly had no special lsm + * mount options. thus we can safely deal with this superblock later + */ + if (!selinux_initialized()) { + if (kern_flags & SECURITY_LSM_NATIVE_LABELS) { + newsbsec->flags |= SE_SBNATIVE; + *set_kern_flags |= SECURITY_LSM_NATIVE_LABELS; + } + goto out; + } + + /* how can we clone if the old one wasn't set up?? */ + BUG_ON(!(oldsbsec->flags & SE_SBINITIALIZED)); + + /* if fs is reusing a sb, make sure that the contexts match */ + if (newsbsec->flags & SE_SBINITIALIZED) { + mutex_unlock(&newsbsec->lock); + if ((kern_flags & SECURITY_LSM_NATIVE_LABELS) && !set_context) + *set_kern_flags |= SECURITY_LSM_NATIVE_LABELS; + return selinux_cmp_sb_context(oldsb, newsb); + } + + newsbsec->flags = oldsbsec->flags; + + newsbsec->sid = oldsbsec->sid; + newsbsec->def_sid = oldsbsec->def_sid; + newsbsec->behavior = oldsbsec->behavior; + newsbsec->creator_sid = oldsbsec->creator_sid; + + if (newsbsec->behavior == SECURITY_FS_USE_NATIVE && + !(kern_flags & SECURITY_LSM_NATIVE_LABELS) && !set_context) { + rc = security_fs_use(newsb); + if (rc) + goto out; + } + + if (kern_flags & SECURITY_LSM_NATIVE_LABELS && !set_context) { + newsbsec->behavior = SECURITY_FS_USE_NATIVE; + *set_kern_flags |= SECURITY_LSM_NATIVE_LABELS; + } + + if (set_context) { + u32 sid = oldsbsec->mntpoint_sid; + + if (!set_fscontext) + newsbsec->sid = sid; + if (!set_rootcontext) { + struct inode_security_struct *newisec = backing_inode_security(newsb->s_root); + newisec->sid = sid; + } + newsbsec->mntpoint_sid = sid; + } + if (set_rootcontext) { + const struct inode_security_struct *oldisec = backing_inode_security(oldsb->s_root); + struct inode_security_struct *newisec = backing_inode_security(newsb->s_root); + + newisec->sid = oldisec->sid; + } + + sb_finish_set_opts(newsb); +out: + mutex_unlock(&newsbsec->lock); + return rc; +} + +/* + * NOTE: the caller is responsible for freeing the memory even if on error. + */ +static int selinux_add_opt(int token, const char *s, void **mnt_opts) +{ + struct selinux_mnt_opts *opts = *mnt_opts; + u32 *dst_sid; + int rc; + + if (token == Opt_seclabel) + /* eaten and completely ignored */ + return 0; + if (!s) + return -EINVAL; + + if (!selinux_initialized()) { + pr_warn("SELinux: Unable to set superblock options before the security server is initialized\n"); + return -EINVAL; + } + + if (!opts) { + opts = kzalloc_obj(*opts); + if (!opts) + return -ENOMEM; + *mnt_opts = opts; + } + + switch (token) { + case Opt_context: + if (opts->context_sid || opts->defcontext_sid) + goto err; + dst_sid = &opts->context_sid; + break; + case Opt_fscontext: + if (opts->fscontext_sid) + goto err; + dst_sid = &opts->fscontext_sid; + break; + case Opt_rootcontext: + if (opts->rootcontext_sid) + goto err; + dst_sid = &opts->rootcontext_sid; + break; + case Opt_defcontext: + if (opts->context_sid || opts->defcontext_sid) + goto err; + dst_sid = &opts->defcontext_sid; + break; + default: + WARN_ON(1); + return -EINVAL; + } + rc = security_context_str_to_sid(s, dst_sid, GFP_KERNEL); + if (rc) + pr_warn("SELinux: security_context_str_to_sid (%s) failed with errno=%d\n", + s, rc); + return rc; + +err: + pr_warn(SEL_MOUNT_FAIL_MSG); + return -EINVAL; +} + +static int show_sid(struct seq_file *m, u32 sid) +{ + char *context = NULL; + u32 len; + int rc; + + rc = security_sid_to_context(sid, &context, &len); + if (!rc) { + bool has_comma = strchr(context, ','); + + seq_putc(m, '='); + if (has_comma) + seq_putc(m, '\"'); + seq_escape(m, context, "\"\n\\"); + if (has_comma) + seq_putc(m, '\"'); + } + kfree(context); + return rc; +} + +static int selinux_sb_show_options(struct seq_file *m, struct super_block *sb) +{ + struct superblock_security_struct *sbsec = selinux_superblock(sb); + int rc; + + if (!(sbsec->flags & SE_SBINITIALIZED)) + return 0; + + if (!selinux_initialized()) + return 0; + + if (sbsec->flags & FSCONTEXT_MNT) { + seq_putc(m, ','); + seq_puts(m, FSCONTEXT_STR); + rc = show_sid(m, sbsec->sid); + if (rc) + return rc; + } + if (sbsec->flags & CONTEXT_MNT) { + seq_putc(m, ','); + seq_puts(m, CONTEXT_STR); + rc = show_sid(m, sbsec->mntpoint_sid); + if (rc) + return rc; + } + if (sbsec->flags & DEFCONTEXT_MNT) { + seq_putc(m, ','); + seq_puts(m, DEFCONTEXT_STR); + rc = show_sid(m, sbsec->def_sid); + if (rc) + return rc; + } + if (sbsec->flags & ROOTCONTEXT_MNT) { + struct dentry *root = sb->s_root; + struct inode_security_struct *isec = backing_inode_security(root); + seq_putc(m, ','); + seq_puts(m, ROOTCONTEXT_STR); + rc = show_sid(m, isec->sid); + if (rc) + return rc; + } + if (sbsec->flags & SBLABEL_MNT) { + seq_putc(m, ','); + seq_puts(m, SECLABEL_STR); + } + return 0; +} + +static inline u16 inode_mode_to_security_class(umode_t mode) +{ + switch (mode & S_IFMT) { + case S_IFSOCK: + return SECCLASS_SOCK_FILE; + case S_IFLNK: + return SECCLASS_LNK_FILE; + case S_IFREG: + return SECCLASS_FILE; + case S_IFBLK: + return SECCLASS_BLK_FILE; + case S_IFDIR: + return SECCLASS_DIR; + case S_IFCHR: + return SECCLASS_CHR_FILE; + case S_IFIFO: + return SECCLASS_FIFO_FILE; + + } + + return SECCLASS_FILE; +} + +static inline int default_protocol_stream(int protocol) +{ + return (protocol == IPPROTO_IP || protocol == IPPROTO_TCP || + protocol == IPPROTO_MPTCP); +} + +static inline int default_protocol_dgram(int protocol) +{ + return (protocol == IPPROTO_IP || protocol == IPPROTO_UDP); +} + +static inline u16 socket_type_to_security_class(int family, int type, int protocol) +{ + bool extsockclass = selinux_policycap_extsockclass(); + + switch (family) { + case PF_UNIX: + switch (type) { + case SOCK_STREAM: + case SOCK_SEQPACKET: + return SECCLASS_UNIX_STREAM_SOCKET; + case SOCK_DGRAM: + case SOCK_RAW: + return SECCLASS_UNIX_DGRAM_SOCKET; + } + break; + case PF_INET: + case PF_INET6: + switch (type) { + case SOCK_STREAM: + case SOCK_SEQPACKET: + if (default_protocol_stream(protocol)) + return SECCLASS_TCP_SOCKET; + else if (extsockclass && protocol == IPPROTO_SCTP) + return SECCLASS_SCTP_SOCKET; + else + return SECCLASS_RAWIP_SOCKET; + case SOCK_DGRAM: + if (default_protocol_dgram(protocol)) + return SECCLASS_UDP_SOCKET; + else if (extsockclass && (protocol == IPPROTO_ICMP || + protocol == IPPROTO_ICMPV6)) + return SECCLASS_ICMP_SOCKET; + else + return SECCLASS_RAWIP_SOCKET; + default: + return SECCLASS_RAWIP_SOCKET; + } + break; + case PF_NETLINK: + switch (protocol) { + case NETLINK_ROUTE: + return SECCLASS_NETLINK_ROUTE_SOCKET; + case NETLINK_SOCK_DIAG: + return SECCLASS_NETLINK_TCPDIAG_SOCKET; + case NETLINK_NFLOG: + return SECCLASS_NETLINK_NFLOG_SOCKET; + case NETLINK_XFRM: + return SECCLASS_NETLINK_XFRM_SOCKET; + case NETLINK_SELINUX: + return SECCLASS_NETLINK_SELINUX_SOCKET; + case NETLINK_ISCSI: + return SECCLASS_NETLINK_ISCSI_SOCKET; + case NETLINK_AUDIT: + return SECCLASS_NETLINK_AUDIT_SOCKET; + case NETLINK_FIB_LOOKUP: + return SECCLASS_NETLINK_FIB_LOOKUP_SOCKET; + case NETLINK_CONNECTOR: + return SECCLASS_NETLINK_CONNECTOR_SOCKET; + case NETLINK_NETFILTER: + return SECCLASS_NETLINK_NETFILTER_SOCKET; + case NETLINK_DNRTMSG: + return SECCLASS_NETLINK_DNRT_SOCKET; + case NETLINK_KOBJECT_UEVENT: + return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET; + case NETLINK_GENERIC: + return SECCLASS_NETLINK_GENERIC_SOCKET; + case NETLINK_SCSITRANSPORT: + return SECCLASS_NETLINK_SCSITRANSPORT_SOCKET; + case NETLINK_RDMA: + return SECCLASS_NETLINK_RDMA_SOCKET; + case NETLINK_CRYPTO: + return SECCLASS_NETLINK_CRYPTO_SOCKET; + default: + return SECCLASS_NETLINK_SOCKET; + } + case PF_PACKET: + return SECCLASS_PACKET_SOCKET; + case PF_KEY: + return SECCLASS_KEY_SOCKET; + case PF_APPLETALK: + return SECCLASS_APPLETALK_SOCKET; + } + + if (extsockclass) { + switch (family) { + case PF_AX25: + return SECCLASS_AX25_SOCKET; + case PF_IPX: + return SECCLASS_IPX_SOCKET; + case PF_NETROM: + return SECCLASS_NETROM_SOCKET; + case PF_ATMPVC: + return SECCLASS_ATMPVC_SOCKET; + case PF_X25: + return SECCLASS_X25_SOCKET; + case PF_ROSE: + return SECCLASS_ROSE_SOCKET; + case PF_DECnet: + return SECCLASS_DECNET_SOCKET; + case PF_ATMSVC: + return SECCLASS_ATMSVC_SOCKET; + case PF_RDS: + return SECCLASS_RDS_SOCKET; + case PF_IRDA: + return SECCLASS_IRDA_SOCKET; + case PF_PPPOX: + return SECCLASS_PPPOX_SOCKET; + case PF_LLC: + return SECCLASS_LLC_SOCKET; + case PF_CAN: + return SECCLASS_CAN_SOCKET; + case PF_TIPC: + return SECCLASS_TIPC_SOCKET; + case PF_BLUETOOTH: + return SECCLASS_BLUETOOTH_SOCKET; + case PF_IUCV: + return SECCLASS_IUCV_SOCKET; + case PF_RXRPC: + return SECCLASS_RXRPC_SOCKET; + case PF_ISDN: + return SECCLASS_ISDN_SOCKET; + case PF_PHONET: + return SECCLASS_PHONET_SOCKET; + case PF_IEEE802154: + return SECCLASS_IEEE802154_SOCKET; + case PF_CAIF: + return SECCLASS_CAIF_SOCKET; + case PF_ALG: + return SECCLASS_ALG_SOCKET; + case PF_NFC: + return SECCLASS_NFC_SOCKET; + case PF_VSOCK: + return SECCLASS_VSOCK_SOCKET; + case PF_KCM: + return SECCLASS_KCM_SOCKET; + case PF_QIPCRTR: + return SECCLASS_QIPCRTR_SOCKET; + case PF_SMC: + return SECCLASS_SMC_SOCKET; + case PF_XDP: + return SECCLASS_XDP_SOCKET; + case PF_MCTP: + return SECCLASS_MCTP_SOCKET; +#if PF_MAX > 46 +#error New address family defined, please update this function. +#endif + } + } + + return SECCLASS_SOCKET; +} + +static int selinux_genfs_get_sid(struct dentry *dentry, + u16 tclass, + u16 flags, + u32 *sid) +{ + int rc; + struct super_block *sb = dentry->d_sb; + char *buffer, *path; + + buffer = kmalloc(PATH_MAX, GFP_KERNEL); + if (!buffer) + return -ENOMEM; + + path = dentry_path_raw(dentry, buffer, PATH_MAX); + if (IS_ERR(path)) + rc = PTR_ERR(path); + else { + if (flags & SE_SBPROC) { + /* each process gets a /proc/PID/ entry. Strip off the + * PID part to get a valid selinux labeling. + * e.g. /proc/1/net/rpc/nfs -> /net/rpc/nfs */ + while (path[1] >= '0' && path[1] <= '9') { + path[1] = '/'; + path++; + } + } + rc = security_genfs_sid(sb->s_type->name, + path, tclass, sid); + if (rc == -ENOENT) { + /* No match in policy, mark as unlabeled. */ + *sid = SECINITSID_UNLABELED; + rc = 0; + } + } + kfree(buffer); + return rc; +} + +static int inode_doinit_use_xattr(struct inode *inode, struct dentry *dentry, + u32 def_sid, u32 *sid) +{ +#define INITCONTEXTLEN 255 + char *context; + unsigned int len; + int rc; + + len = INITCONTEXTLEN; + context = kmalloc(len + 1, GFP_NOFS); + if (!context) + return -ENOMEM; + + context[len] = '\0'; + rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, context, len); + if (rc == -ERANGE) { + kfree(context); + + /* Need a larger buffer. Query for the right size. */ + rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, NULL, 0); + if (rc < 0) + return rc; + + len = rc; + context = kmalloc(len + 1, GFP_NOFS); + if (!context) + return -ENOMEM; + + context[len] = '\0'; + rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, + context, len); + } + if (rc < 0) { + kfree(context); + if (rc != -ENODATA) { + pr_warn("SELinux: %s: getxattr returned %d for dev=%s ino=%llu\n", + __func__, -rc, inode->i_sb->s_id, inode->i_ino); + return rc; + } + *sid = def_sid; + return 0; + } + + rc = security_context_to_sid_default(context, rc, sid, + def_sid, GFP_NOFS); + if (rc) { + char *dev = inode->i_sb->s_id; + u64 ino = inode->i_ino; + + if (rc == -EINVAL) { + pr_notice_ratelimited("SELinux: inode=%llu on dev=%s was found to have an invalid context=%s. This indicates you may need to relabel the inode or the filesystem in question.\n", + ino, dev, context); + } else { + pr_warn("SELinux: %s: context_to_sid(%s) returned %d for dev=%s ino=%llu\n", + __func__, context, -rc, dev, ino); + } + } + kfree(context); + return 0; +} + +/* The inode's security attributes must be initialized before first use. */ +static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry) +{ + struct superblock_security_struct *sbsec = NULL; + struct inode_security_struct *isec = selinux_inode(inode); + u32 task_sid, sid = 0; + u16 sclass; + struct dentry *dentry; + int rc = 0; + + /* check below is racy, but we will recheck with lock held */ + if (data_race(isec->initialized == LABEL_INITIALIZED)) + return 0; + + spin_lock(&isec->lock); + if (isec->initialized == LABEL_INITIALIZED) + goto out_unlock; + + if (isec->sclass == SECCLASS_FILE) + isec->sclass = inode_mode_to_security_class(inode->i_mode); + + sbsec = selinux_superblock(inode->i_sb); + if (!(sbsec->flags & SE_SBINITIALIZED)) { + /* Defer initialization until selinux_complete_init, + after the initial policy is loaded and the security + server is ready to handle calls. */ + spin_lock(&sbsec->isec_lock); + if (list_empty(&isec->list)) + list_add(&isec->list, &sbsec->isec_head); + spin_unlock(&sbsec->isec_lock); + goto out_unlock; + } + + sclass = isec->sclass; + task_sid = isec->task_sid; + sid = isec->sid; + isec->initialized = LABEL_PENDING; + spin_unlock(&isec->lock); + + switch (sbsec->behavior) { + /* + * In case of SECURITY_FS_USE_NATIVE we need to re-fetch the labels + * via xattr when called from delayed_superblock_init(). + */ + case SECURITY_FS_USE_NATIVE: + case SECURITY_FS_USE_XATTR: + if (!(inode->i_opflags & IOP_XATTR)) { + sid = sbsec->def_sid; + break; + } + /* Need a dentry, since the xattr API requires one. + Life would be simpler if we could just pass the inode. */ + if (opt_dentry) { + /* Called from d_instantiate or d_splice_alias. */ + dentry = dget(opt_dentry); + } else { + /* + * Called from selinux_complete_init, try to find a dentry. + * Some filesystems really want a connected one, so try + * that first. We could split SECURITY_FS_USE_XATTR in + * two, depending upon that... + */ + dentry = d_find_alias(inode); + if (!dentry) + dentry = d_find_any_alias(inode); + } + if (!dentry) { + /* + * this is can be hit on boot when a file is accessed + * before the policy is loaded. When we load policy we + * may find inodes that have no dentry on the + * sbsec->isec_head list. No reason to complain as these + * will get fixed up the next time we go through + * inode_doinit with a dentry, before these inodes could + * be used again by userspace. + */ + goto out_invalid; + } + + rc = inode_doinit_use_xattr(inode, dentry, sbsec->def_sid, + &sid); + dput(dentry); + if (rc) + goto out; + break; + case SECURITY_FS_USE_TASK: + sid = task_sid; + break; + case SECURITY_FS_USE_TRANS: + /* Default to the fs SID. */ + sid = sbsec->sid; + + /* Try to obtain a transition SID. */ + rc = security_transition_sid(task_sid, sid, + sclass, NULL, &sid); + if (rc) + goto out; + break; + case SECURITY_FS_USE_MNTPOINT: + sid = sbsec->mntpoint_sid; + break; + default: + /* Default to the fs superblock SID. */ + sid = sbsec->sid; + + if ((sbsec->flags & SE_SBGENFS) && + (!S_ISLNK(inode->i_mode) || + selinux_policycap_genfs_seclabel_symlinks())) { + /* We must have a dentry to determine the label on + * procfs inodes */ + if (opt_dentry) { + /* Called from d_instantiate or + * d_splice_alias. */ + dentry = dget(opt_dentry); + } else { + /* Called from selinux_complete_init, try to + * find a dentry. Some filesystems really want + * a connected one, so try that first. + */ + dentry = d_find_alias(inode); + if (!dentry) + dentry = d_find_any_alias(inode); + } + /* + * This can be hit on boot when a file is accessed + * before the policy is loaded. When we load policy we + * may find inodes that have no dentry on the + * sbsec->isec_head list. No reason to complain as + * these will get fixed up the next time we go through + * inode_doinit() with a dentry, before these inodes + * could be used again by userspace. + */ + if (!dentry) + goto out_invalid; + rc = selinux_genfs_get_sid(dentry, sclass, + sbsec->flags, &sid); + if (rc) { + dput(dentry); + goto out; + } + + if ((sbsec->flags & SE_SBGENFS_XATTR) && + (inode->i_opflags & IOP_XATTR)) { + rc = inode_doinit_use_xattr(inode, dentry, + sid, &sid); + if (rc) { + dput(dentry); + goto out; + } + } + dput(dentry); + } + break; + } + +out: + spin_lock(&isec->lock); + if (isec->initialized == LABEL_PENDING) { + if (rc) { + isec->initialized = LABEL_INVALID; + goto out_unlock; + } + isec->initialized = LABEL_INITIALIZED; + isec->sid = sid; + } + +out_unlock: + spin_unlock(&isec->lock); + return rc; + +out_invalid: + spin_lock(&isec->lock); + if (isec->initialized == LABEL_PENDING) { + isec->initialized = LABEL_INVALID; + isec->sid = sid; + } + spin_unlock(&isec->lock); + return 0; +} + +/* Convert a Linux signal to an access vector. */ +static inline u32 signal_to_av(int sig) +{ + u32 perm = 0; + + switch (sig) { + case SIGCHLD: + /* Commonly granted from child to parent. */ + perm = PROCESS__SIGCHLD; + break; + case SIGKILL: + /* Cannot be caught or ignored */ + perm = PROCESS__SIGKILL; + break; + case SIGSTOP: + /* Cannot be caught or ignored */ + perm = PROCESS__SIGSTOP; + break; + default: + /* All other signals. */ + perm = PROCESS__SIGNAL; + break; + } + + return perm; +} + +#if CAP_LAST_CAP > 63 +#error Fix SELinux to handle capabilities > 63. +#endif + +/* Check whether a task is allowed to use a capability. */ +static int cred_has_capability(const struct cred *cred, + int cap, unsigned int opts, bool initns) +{ + struct common_audit_data ad; + struct av_decision avd; + u16 sclass; + u32 sid = cred_sid(cred); + u32 av = CAP_TO_MASK(cap); + int rc; + + ad.type = LSM_AUDIT_DATA_CAP; + ad.u.cap = cap; + + switch (CAP_TO_INDEX(cap)) { + case 0: + sclass = initns ? SECCLASS_CAPABILITY : SECCLASS_CAP_USERNS; + break; + case 1: + sclass = initns ? SECCLASS_CAPABILITY2 : SECCLASS_CAP2_USERNS; + break; + default: + pr_err("SELinux: out of range capability %d\n", cap); + return -EINVAL; + } + + rc = avc_has_perm_noaudit(sid, sid, sclass, av, 0, &avd); + if (!(opts & CAP_OPT_NOAUDIT)) { + int rc2 = avc_audit(sid, sid, sclass, av, &avd, rc, &ad); + if (rc2) + return rc2; + } + return rc; +} + +/* Check whether a task has a particular permission to an inode. + The 'adp' parameter is optional and allows other audit + data to be passed (e.g. the dentry). */ +static int inode_has_perm(const struct cred *cred, + struct inode *inode, + u32 perms, + struct common_audit_data *adp) +{ + struct inode_security_struct *isec; + u32 sid; + + if (unlikely(IS_PRIVATE(inode))) + return 0; + + sid = cred_sid(cred); + isec = selinux_inode(inode); + + return avc_has_perm(sid, isec->sid, isec->sclass, perms, adp); +} + +/* Same as inode_has_perm, but pass explicit audit data containing + the dentry to help the auditing code to more easily generate the + pathname if needed. */ +static inline int dentry_has_perm(const struct cred *cred, + struct dentry *dentry, + u32 av) +{ + struct common_audit_data ad; + struct inode *inode = d_backing_inode(dentry); + struct inode_security_struct *isec = selinux_inode(inode); + + ad.type = LSM_AUDIT_DATA_DENTRY; + ad.u.dentry = dentry; + /* check below is racy, but revalidate will recheck with lock held */ + if (data_race(unlikely(isec->initialized != LABEL_INITIALIZED))) + __inode_security_revalidate(inode, dentry, true); + return inode_has_perm(cred, inode, av, &ad); +} + +/* Same as inode_has_perm, but pass explicit audit data containing + the path to help the auditing code to more easily generate the + pathname if needed. */ +static inline int path_has_perm(const struct cred *cred, + const struct path *path, + u32 av) +{ + struct common_audit_data ad; + struct inode *inode = d_backing_inode(path->dentry); + struct inode_security_struct *isec = selinux_inode(inode); + + ad.type = LSM_AUDIT_DATA_PATH; + ad.u.path = *path; + /* check below is racy, but revalidate will recheck with lock held */ + if (data_race(unlikely(isec->initialized != LABEL_INITIALIZED))) + __inode_security_revalidate(inode, path->dentry, true); + return inode_has_perm(cred, inode, av, &ad); +} + +/* Same as path_has_perm, but uses the inode from the file struct. */ +static inline int file_path_has_perm(const struct cred *cred, + struct file *file, + u32 av) +{ + struct common_audit_data ad; + + ad.type = LSM_AUDIT_DATA_FILE; + ad.u.file = file; + return inode_has_perm(cred, file_inode(file), av, &ad); +} + +#ifdef CONFIG_BPF_SYSCALL +static int bpf_fd_pass(const struct file *file, u32 sid); +#endif + +static int __file_has_perm(const struct cred *cred, const struct file *file, + u32 av, bool bf_user_file) + +{ + struct common_audit_data ad; + struct inode *inode; + u32 ssid = cred_sid(cred); + u32 tsid_fd; + int rc; + + if (bf_user_file) { + struct backing_file_security_struct *bfsec; + const struct path *path; + + if (WARN_ON(!(file->f_mode & FMODE_BACKING))) + return -EIO; + + bfsec = selinux_backing_file(file); + path = backing_file_user_path(file); + tsid_fd = bfsec->uf_sid; + inode = d_inode(path->dentry); + + ad.type = LSM_AUDIT_DATA_PATH; + ad.u.path = *path; + } else { + struct file_security_struct *fsec = selinux_file(file); + + tsid_fd = fsec->sid; + inode = file_inode(file); + + ad.type = LSM_AUDIT_DATA_FILE; + ad.u.file = file; + } + + if (ssid != tsid_fd) { + rc = avc_has_perm(ssid, tsid_fd, SECCLASS_FD, FD__USE, &ad); + if (rc) + return rc; + } + +#ifdef CONFIG_BPF_SYSCALL + /* regardless of backing vs user file, use the underlying file here */ + rc = bpf_fd_pass(file, ssid); + if (rc) + return rc; +#endif + + /* av is zero if only checking access to the descriptor. */ + if (av) + return inode_has_perm(cred, inode, av, &ad); + + return 0; +} + +/* Check whether a task can use an open file descriptor to + access an inode in a given way. Check access to the + descriptor itself, and then use dentry_has_perm to + check a particular permission to the file. + Access to the descriptor is implicitly granted if it + has the same SID as the process. If av is zero, then + access to the file is not checked, e.g. for cases + where only the descriptor is affected like seek. */ +static inline int file_has_perm(const struct cred *cred, + const struct file *file, u32 av) +{ + return __file_has_perm(cred, file, av, false); +} + +/* + * Determine the label for an inode that might be unioned. + */ +static int +selinux_determine_inode_label(const struct cred_security_struct *crsec, + struct inode *dir, + const struct qstr *name, u16 tclass, + u32 *_new_isid) +{ + const struct superblock_security_struct *sbsec = + selinux_superblock(dir->i_sb); + + if ((sbsec->flags & SE_SBINITIALIZED) && + (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)) { + *_new_isid = sbsec->mntpoint_sid; + } else if ((sbsec->flags & SBLABEL_MNT) && + crsec->create_sid) { + *_new_isid = crsec->create_sid; + } else { + const struct inode_security_struct *dsec = inode_security(dir); + return security_transition_sid(crsec->sid, + dsec->sid, tclass, + name, _new_isid); + } + + return 0; +} + +/* Check whether a task can create a file. */ +static int may_create(struct inode *dir, + struct dentry *dentry, + u16 tclass) +{ + const struct cred_security_struct *crsec = selinux_cred(current_cred()); + struct inode_security_struct *dsec; + struct superblock_security_struct *sbsec; + u32 sid, newsid; + struct common_audit_data ad; + int rc; + + dsec = inode_security(dir); + sbsec = selinux_superblock(dir->i_sb); + + sid = crsec->sid; + + ad.type = LSM_AUDIT_DATA_DENTRY; + ad.u.dentry = dentry; + + rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR, + DIR__ADD_NAME | DIR__SEARCH, + &ad); + if (rc) + return rc; + + rc = selinux_determine_inode_label(crsec, dir, &dentry->d_name, tclass, + &newsid); + if (rc) + return rc; + + rc = avc_has_perm(sid, newsid, tclass, FILE__CREATE, &ad); + if (rc) + return rc; + + return avc_has_perm(newsid, sbsec->sid, + SECCLASS_FILESYSTEM, + FILESYSTEM__ASSOCIATE, &ad); +} + +#define MAY_LINK 0 +#define MAY_UNLINK 1 +#define MAY_RMDIR 2 + +/* Check whether a task can link, unlink, or rmdir a file/directory. */ +static int may_link(struct inode *dir, + struct dentry *dentry, + int kind) + +{ + struct inode_security_struct *dsec, *isec; + struct common_audit_data ad; + u32 sid = current_sid(); + u32 av; + int rc; + + dsec = inode_security(dir); + isec = backing_inode_security(dentry); + + ad.type = LSM_AUDIT_DATA_DENTRY; + ad.u.dentry = dentry; + + av = DIR__SEARCH; + av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME); + rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR, av, &ad); + if (rc) + return rc; + + switch (kind) { + case MAY_LINK: + av = FILE__LINK; + break; + case MAY_UNLINK: + av = FILE__UNLINK; + break; + case MAY_RMDIR: + av = DIR__RMDIR; + break; + default: + pr_warn("SELinux: %s: unrecognized kind %d\n", + __func__, kind); + return 0; + } + + rc = avc_has_perm(sid, isec->sid, isec->sclass, av, &ad); + return rc; +} + +static inline int may_rename(struct inode *old_dir, + struct dentry *old_dentry, + struct inode *new_dir, + struct dentry *new_dentry) +{ + struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec; + struct common_audit_data ad; + u32 sid = current_sid(); + u32 av; + int old_is_dir, new_is_dir; + int rc; + + old_dsec = inode_security(old_dir); + old_isec = backing_inode_security(old_dentry); + old_is_dir = d_is_dir(old_dentry); + new_dsec = inode_security(new_dir); + + ad.type = LSM_AUDIT_DATA_DENTRY; + + ad.u.dentry = old_dentry; + rc = avc_has_perm(sid, old_dsec->sid, SECCLASS_DIR, + DIR__REMOVE_NAME | DIR__SEARCH, &ad); + if (rc) + return rc; + rc = avc_has_perm(sid, old_isec->sid, + old_isec->sclass, FILE__RENAME, &ad); + if (rc) + return rc; + if (old_is_dir && new_dir != old_dir) { + rc = avc_has_perm(sid, old_isec->sid, + old_isec->sclass, DIR__REPARENT, &ad); + if (rc) + return rc; + } + + ad.u.dentry = new_dentry; + av = DIR__ADD_NAME | DIR__SEARCH; + if (d_is_positive(new_dentry)) + av |= DIR__REMOVE_NAME; + rc = avc_has_perm(sid, new_dsec->sid, SECCLASS_DIR, av, &ad); + if (rc) + return rc; + if (d_is_positive(new_dentry)) { + new_isec = backing_inode_security(new_dentry); + new_is_dir = d_is_dir(new_dentry); + rc = avc_has_perm(sid, new_isec->sid, + new_isec->sclass, + (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad); + if (rc) + return rc; + } + + return 0; +} + +/* Check whether a task can perform a filesystem operation. */ +static int superblock_has_perm(const struct cred *cred, + const struct super_block *sb, + u32 perms, + struct common_audit_data *ad) +{ + struct superblock_security_struct *sbsec; + u32 sid = cred_sid(cred); + + sbsec = selinux_superblock(sb); + return avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM, perms, ad); +} + +/* Convert a Linux mode and permission mask to an access vector. */ +static inline u32 file_mask_to_av(int mode, int mask) +{ + u32 av = 0; + + if (!S_ISDIR(mode)) { + if (mask & MAY_EXEC) + av |= FILE__EXECUTE; + if (mask & MAY_READ) + av |= FILE__READ; + + if (mask & MAY_APPEND) + av |= FILE__APPEND; + else if (mask & MAY_WRITE) + av |= FILE__WRITE; + + } else { + if (mask & MAY_EXEC) + av |= DIR__SEARCH; + if (mask & MAY_WRITE) + av |= DIR__WRITE; + if (mask & MAY_READ) + av |= DIR__READ; + } + + return av; +} + +/* Convert a Linux file to an access vector. */ +static inline u32 file_to_av(const struct file *file) +{ + u32 av = 0; + + if (file->f_mode & FMODE_READ) + av |= FILE__READ; + if (file->f_mode & FMODE_WRITE) { + if (file->f_flags & O_APPEND) + av |= FILE__APPEND; + else + av |= FILE__WRITE; + } + if (!av) { + /* + * Special file opened with flags 3 for ioctl-only use. + */ + av = FILE__IOCTL; + } + + return av; +} + +/* + * Convert a file to an access vector and include the correct + * open permission. + */ +static inline u32 open_file_to_av(struct file *file) +{ + u32 av = file_to_av(file); + struct inode *inode = file_inode(file); + + if (selinux_policycap_openperm() && + inode->i_sb->s_magic != SOCKFS_MAGIC) + av |= FILE__OPEN; + + return av; +} + +/* Hook functions begin here. */ + +static int selinux_binder_set_context_mgr(const struct cred *mgr) +{ + return avc_has_perm(current_sid(), cred_sid(mgr), SECCLASS_BINDER, + BINDER__SET_CONTEXT_MGR, NULL); +} + +static int selinux_binder_transaction(const struct cred *from, + const struct cred *to) +{ + u32 mysid = current_sid(); + u32 fromsid = cred_sid(from); + u32 tosid = cred_sid(to); + int rc; + + if (mysid != fromsid) { + rc = avc_has_perm(mysid, fromsid, SECCLASS_BINDER, + BINDER__IMPERSONATE, NULL); + if (rc) + return rc; + } + + return avc_has_perm(fromsid, tosid, + SECCLASS_BINDER, BINDER__CALL, NULL); +} + +static int selinux_binder_transfer_binder(const struct cred *from, + const struct cred *to) +{ + return avc_has_perm(cred_sid(from), cred_sid(to), + SECCLASS_BINDER, BINDER__TRANSFER, + NULL); +} + +static int selinux_binder_transfer_file(const struct cred *from, + const struct cred *to, + const struct file *file) +{ + u32 sid = cred_sid(to); + struct file_security_struct *fsec = selinux_file(file); + struct dentry *dentry = file->f_path.dentry; + struct inode_security_struct *isec; + struct common_audit_data ad; + int rc; + + ad.type = LSM_AUDIT_DATA_PATH; + ad.u.path = file->f_path; + + if (sid != fsec->sid) { + rc = avc_has_perm(sid, fsec->sid, + SECCLASS_FD, + FD__USE, + &ad); + if (rc) + return rc; + } + +#ifdef CONFIG_BPF_SYSCALL + rc = bpf_fd_pass(file, sid); + if (rc) + return rc; +#endif + + if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) + return 0; + + isec = backing_inode_security(dentry); + return avc_has_perm(sid, isec->sid, isec->sclass, file_to_av(file), + &ad); +} + +static int selinux_ptrace_access_check(struct task_struct *child, + unsigned int mode) +{ + u32 sid = current_sid(); + u32 csid = task_sid_obj(child); + + if (mode & PTRACE_MODE_READ) + return avc_has_perm(sid, csid, SECCLASS_FILE, FILE__READ, + NULL); + + return avc_has_perm(sid, csid, SECCLASS_PROCESS, PROCESS__PTRACE, + NULL); +} + +static int selinux_ptrace_traceme(struct task_struct *parent) +{ + return avc_has_perm(task_sid_obj(parent), task_sid_obj(current), + SECCLASS_PROCESS, PROCESS__PTRACE, NULL); +} + +static int selinux_capget(const struct task_struct *target, kernel_cap_t *effective, + kernel_cap_t *inheritable, kernel_cap_t *permitted) +{ + return avc_has_perm(current_sid(), task_sid_obj(target), + SECCLASS_PROCESS, PROCESS__GETCAP, NULL); +} + +static int selinux_capset(struct cred *new, const struct cred *old, + const kernel_cap_t *effective, + const kernel_cap_t *inheritable, + const kernel_cap_t *permitted) +{ + return avc_has_perm(cred_sid(old), cred_sid(new), SECCLASS_PROCESS, + PROCESS__SETCAP, NULL); +} + +/* + * (This comment used to live with the selinux_task_setuid hook, + * which was removed). + * + * Since setuid only affects the current process, and since the SELinux + * controls are not based on the Linux identity attributes, SELinux does not + * need to control this operation. However, SELinux does control the use of + * the CAP_SETUID and CAP_SETGID capabilities using the capable hook. + */ + +static int selinux_capable(const struct cred *cred, struct user_namespace *ns, + int cap, unsigned int opts) +{ + return cred_has_capability(cred, cap, opts, ns == &init_user_ns); +} + +static int selinux_quotactl(int cmds, int type, int id, const struct super_block *sb) +{ + const struct cred *cred = current_cred(); + int rc = 0; + + if (!sb) + return 0; + + switch (cmds) { + case Q_SYNC: + case Q_QUOTAON: + case Q_QUOTAOFF: + case Q_SETINFO: + case Q_SETQUOTA: + case Q_XQUOTAOFF: + case Q_XQUOTAON: + case Q_XSETQLIM: + rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAMOD, NULL); + break; + case Q_GETFMT: + case Q_GETINFO: + case Q_GETQUOTA: + case Q_XGETQUOTA: + case Q_XGETQSTAT: + case Q_XGETQSTATV: + case Q_XGETNEXTQUOTA: + rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAGET, NULL); + break; + default: + rc = 0; /* let the kernel handle invalid cmds */ + break; + } + return rc; +} + +static int selinux_quota_on(struct dentry *dentry) +{ + const struct cred *cred = current_cred(); + + return dentry_has_perm(cred, dentry, FILE__QUOTAON); +} + +static int selinux_syslog(int type) +{ + switch (type) { + case SYSLOG_ACTION_READ_ALL: /* Read last kernel messages */ + case SYSLOG_ACTION_SIZE_BUFFER: /* Return size of the log buffer */ + return avc_has_perm(current_sid(), SECINITSID_KERNEL, + SECCLASS_SYSTEM, SYSTEM__SYSLOG_READ, NULL); + case SYSLOG_ACTION_CONSOLE_OFF: /* Disable logging to console */ + case SYSLOG_ACTION_CONSOLE_ON: /* Enable logging to console */ + /* Set level of messages printed to console */ + case SYSLOG_ACTION_CONSOLE_LEVEL: + return avc_has_perm(current_sid(), SECINITSID_KERNEL, + SECCLASS_SYSTEM, SYSTEM__SYSLOG_CONSOLE, + NULL); + } + /* All other syslog types */ + return avc_has_perm(current_sid(), SECINITSID_KERNEL, + SECCLASS_SYSTEM, SYSTEM__SYSLOG_MOD, NULL); +} + +/* + * Check permission for allocating a new virtual mapping. Returns + * 0 if permission is granted, negative error code if not. + * + * Do not audit the selinux permission check, as this is applied to all + * processes that allocate mappings. + */ +static int selinux_vm_enough_memory(struct mm_struct *mm, long pages) +{ + return cred_has_capability(current_cred(), CAP_SYS_ADMIN, + CAP_OPT_NOAUDIT, true); +} + +/* binprm security operations */ + +static u32 ptrace_parent_sid(void) +{ + u32 sid = 0; + struct task_struct *tracer; + + rcu_read_lock(); + tracer = ptrace_parent(current); + if (tracer) + sid = task_sid_obj(tracer); + rcu_read_unlock(); + + return sid; +} + +static int check_nnp_nosuid(const struct linux_binprm *bprm, + const struct cred_security_struct *old_crsec, + const struct cred_security_struct *new_crsec) +{ + int nnp = (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS); + int nosuid = !mnt_may_suid(bprm->file->f_path.mnt); + int rc; + u32 av; + + if (!nnp && !nosuid) + return 0; /* neither NNP nor nosuid */ + + if (new_crsec->sid == old_crsec->sid) + return 0; /* No change in credentials */ + + /* + * If the policy enables the nnp_nosuid_transition policy capability, + * then we permit transitions under NNP or nosuid if the + * policy allows the corresponding permission between + * the old and new contexts. + */ + if (selinux_policycap_nnp_nosuid_transition()) { + av = 0; + if (nnp) + av |= PROCESS2__NNP_TRANSITION; + if (nosuid) + av |= PROCESS2__NOSUID_TRANSITION; + rc = avc_has_perm(old_crsec->sid, new_crsec->sid, + SECCLASS_PROCESS2, av, NULL); + if (!rc) + return 0; + } + + /* + * We also permit NNP or nosuid transitions to bounded SIDs, + * i.e. SIDs that are guaranteed to only be allowed a subset + * of the permissions of the current SID. + */ + rc = security_bounded_transition(old_crsec->sid, + new_crsec->sid); + if (!rc) + return 0; + + /* + * On failure, preserve the errno values for NNP vs nosuid. + * NNP: Operation not permitted for caller. + * nosuid: Permission denied to file. + */ + if (nnp) + return -EPERM; + return -EACCES; +} + +static int selinux_bprm_creds_for_exec(struct linux_binprm *bprm) +{ + const struct cred_security_struct *old_crsec; + struct cred_security_struct *new_crsec; + struct inode_security_struct *isec; + struct common_audit_data ad; + struct inode *inode = file_inode(bprm->file); + int rc; + + /* SELinux context only depends on initial program or script and not + * the script interpreter */ + + old_crsec = selinux_cred(current_cred()); + new_crsec = selinux_cred(bprm->cred); + isec = inode_security(inode); + + if (WARN_ON(isec->sclass != SECCLASS_FILE && + isec->sclass != SECCLASS_MEMFD_FILE)) + return -EACCES; + + /* Default to the current task SID. */ + new_crsec->sid = old_crsec->sid; + new_crsec->osid = old_crsec->sid; + + /* Reset fs, key, and sock SIDs on execve. */ + new_crsec->create_sid = 0; + new_crsec->keycreate_sid = 0; + new_crsec->sockcreate_sid = 0; + + /* + * Before policy is loaded, label any task outside kernel space + * as SECINITSID_INIT, so that any userspace tasks surviving from + * early boot end up with a label different from SECINITSID_KERNEL + * (if the policy chooses to set SECINITSID_INIT != SECINITSID_KERNEL). + */ + if (!selinux_initialized()) { + new_crsec->sid = SECINITSID_INIT; + /* also clear the exec_sid just in case */ + new_crsec->exec_sid = 0; + return 0; + } + + if (old_crsec->exec_sid) { + new_crsec->sid = old_crsec->exec_sid; + /* Reset exec SID on execve. */ + new_crsec->exec_sid = 0; + + /* Fail on NNP or nosuid if not an allowed transition. */ + rc = check_nnp_nosuid(bprm, old_crsec, new_crsec); + if (rc) + return rc; + } else { + /* Check for a default transition on this program. */ + rc = security_transition_sid(old_crsec->sid, + isec->sid, SECCLASS_PROCESS, NULL, + &new_crsec->sid); + if (rc) + return rc; + + /* + * Fallback to old SID on NNP or nosuid if not an allowed + * transition. + */ + rc = check_nnp_nosuid(bprm, old_crsec, new_crsec); + if (rc) + new_crsec->sid = old_crsec->sid; + } + + ad.type = LSM_AUDIT_DATA_FILE; + ad.u.file = bprm->file; + + if (new_crsec->sid == old_crsec->sid) { + rc = avc_has_perm(old_crsec->sid, isec->sid, isec->sclass, + FILE__EXECUTE_NO_TRANS, &ad); + if (rc) + return rc; + } else { + /* Check permissions for the transition. */ + rc = avc_has_perm(old_crsec->sid, new_crsec->sid, + SECCLASS_PROCESS, PROCESS__TRANSITION, &ad); + if (rc) + return rc; + + rc = avc_has_perm(new_crsec->sid, isec->sid, isec->sclass, + FILE__ENTRYPOINT, &ad); + if (rc) + return rc; + + /* Check for shared state */ + if (bprm->unsafe & LSM_UNSAFE_SHARE) { + rc = avc_has_perm(old_crsec->sid, new_crsec->sid, + SECCLASS_PROCESS, PROCESS__SHARE, + NULL); + if (rc) + return -EPERM; + } + + /* Make sure that anyone attempting to ptrace over a task that + * changes its SID has the appropriate permit */ + if (bprm->unsafe & LSM_UNSAFE_PTRACE) { + u32 ptsid = ptrace_parent_sid(); + if (ptsid != 0) { + rc = avc_has_perm(ptsid, new_crsec->sid, + SECCLASS_PROCESS, + PROCESS__PTRACE, NULL); + if (rc) + return -EPERM; + } + } + + /* Clear any possibly unsafe personality bits on exec: */ + bprm->per_clear |= PER_CLEAR_ON_SETID; + + /* Enable secure mode for SIDs transitions unless + the noatsecure permission is granted between + the two SIDs, i.e. ahp returns 0. */ + rc = avc_has_perm(old_crsec->sid, new_crsec->sid, + SECCLASS_PROCESS, PROCESS__NOATSECURE, + NULL); + bprm->secureexec |= !!rc; + } + + return 0; +} + +static int match_file(const void *p, struct file *file, unsigned fd) +{ + return file_has_perm(p, file, file_to_av(file)) ? fd + 1 : 0; +} + +/* Derived from fs/exec.c:flush_old_files. */ +static inline void flush_unauthorized_files(const struct cred *cred, + struct files_struct *files) +{ + struct file *file, *devnull = NULL; + struct tty_struct *tty; + int drop_tty = 0; + unsigned n; + + tty = get_current_tty(); + if (tty) { + spin_lock(&tty->files_lock); + if (!list_empty(&tty->tty_files)) { + struct tty_file_private *file_priv; + + /* Revalidate access to controlling tty. + Use file_path_has_perm on the tty path directly + rather than using file_has_perm, as this particular + open file may belong to another process and we are + only interested in the inode-based check here. */ + file_priv = list_first_entry(&tty->tty_files, + struct tty_file_private, list); + file = file_priv->file; + if (file_path_has_perm(cred, file, FILE__READ | FILE__WRITE)) + drop_tty = 1; + } + spin_unlock(&tty->files_lock); + tty_kref_put(tty); + } + /* Reset controlling tty. */ + if (drop_tty) + no_tty(); + + /* Revalidate access to inherited open files. */ + n = iterate_fd(files, 0, match_file, cred); + if (!n) /* none found? */ + return; + + devnull = dentry_open(&selinux_null, O_RDWR, cred); + if (IS_ERR(devnull)) + devnull = NULL; + /* replace all the matching ones with this */ + do { + replace_fd(n - 1, devnull, 0); + } while ((n = iterate_fd(files, n, match_file, cred)) != 0); + if (devnull) + fput(devnull); +} + +/* + * Prepare a process for imminent new credential changes due to exec + */ +static void selinux_bprm_committing_creds(const struct linux_binprm *bprm) +{ + struct cred_security_struct *new_crsec; + struct rlimit *rlim, *initrlim; + int rc, i; + + new_crsec = selinux_cred(bprm->cred); + if (new_crsec->sid == new_crsec->osid) + return; + + /* Close files for which the new task SID is not authorized. */ + flush_unauthorized_files(bprm->cred, current->files); + + /* Always clear parent death signal on SID transitions. */ + current->pdeath_signal = 0; + + /* Check whether the new SID can inherit resource limits from the old + * SID. If not, reset all soft limits to the lower of the current + * task's hard limit and the init task's soft limit. + * + * Note that the setting of hard limits (even to lower them) can be + * controlled by the setrlimit check. The inclusion of the init task's + * soft limit into the computation is to avoid resetting soft limits + * higher than the default soft limit for cases where the default is + * lower than the hard limit, e.g. RLIMIT_CORE or RLIMIT_STACK. + */ + rc = avc_has_perm(new_crsec->osid, new_crsec->sid, SECCLASS_PROCESS, + PROCESS__RLIMITINH, NULL); + if (rc) { + /* protect against do_prlimit() */ + task_lock(current); + for (i = 0; i < RLIM_NLIMITS; i++) { + rlim = current->signal->rlim + i; + initrlim = init_task.signal->rlim + i; + rlim->rlim_cur = min(rlim->rlim_max, initrlim->rlim_cur); + } + task_unlock(current); + if (IS_ENABLED(CONFIG_POSIX_TIMERS)) + update_rlimit_cpu(current, rlimit(RLIMIT_CPU)); + } +} + +/* + * Clean up the process immediately after the installation of new credentials + * due to exec + */ +static void selinux_bprm_committed_creds(const struct linux_binprm *bprm) +{ + const struct cred_security_struct *crsec = selinux_cred(current_cred()); + u32 osid, sid; + int rc; + + osid = crsec->osid; + sid = crsec->sid; + + if (sid == osid) + return; + + /* Check whether the new SID can inherit signal state from the old SID. + * If not, clear itimers to avoid subsequent signal generation and + * flush and unblock signals. + * + * This must occur _after_ the task SID has been updated so that any + * kill done after the flush will be checked against the new SID. + */ + rc = avc_has_perm(osid, sid, SECCLASS_PROCESS, PROCESS__SIGINH, NULL); + if (rc) { + clear_itimer(); + + spin_lock_irq(&unrcu_pointer(current->sighand)->siglock); + if (!fatal_signal_pending(current)) { + flush_sigqueue(¤t->pending); + flush_sigqueue(¤t->signal->shared_pending); + flush_signal_handlers(current, 1); + sigemptyset(¤t->blocked); + recalc_sigpending(); + } + spin_unlock_irq(&unrcu_pointer(current->sighand)->siglock); + } + + /* Wake up the parent if it is waiting so that it can recheck + * wait permission to the new task SID. */ + read_lock(&tasklist_lock); + __wake_up_parent(current, unrcu_pointer(current->real_parent)); + read_unlock(&tasklist_lock); +} + +/* superblock security operations */ + +static int selinux_sb_alloc_security(struct super_block *sb) +{ + struct superblock_security_struct *sbsec = selinux_superblock(sb); + + mutex_init(&sbsec->lock); + INIT_LIST_HEAD(&sbsec->isec_head); + spin_lock_init(&sbsec->isec_lock); + sbsec->sid = SECINITSID_UNLABELED; + sbsec->def_sid = SECINITSID_FILE; + sbsec->mntpoint_sid = SECINITSID_UNLABELED; + sbsec->creator_sid = SECINITSID_UNLABELED; + + return 0; +} + +static inline int opt_len(const char *s) +{ + bool open_quote = false; + int len; + char c; + + for (len = 0; (c = s[len]) != '\0'; len++) { + if (c == '"') + open_quote = !open_quote; + if (c == ',' && !open_quote) + break; + } + return len; +} + +static int selinux_sb_eat_lsm_opts(char *options, void **mnt_opts) +{ + char *from = options; + char *to = options; + bool first = true; + int rc; + + while (1) { + int len = opt_len(from); + int token; + char *arg = NULL; + + token = match_opt_prefix(from, len, &arg); + + if (token != Opt_error) { + char *p, *q; + + /* strip quotes */ + if (arg) { + for (p = q = arg; p < from + len; p++) { + char c = *p; + if (c != '"') + *q++ = c; + } + arg = kmemdup_nul(arg, q - arg, GFP_KERNEL); + if (!arg) { + rc = -ENOMEM; + goto free_opt; + } + } + rc = selinux_add_opt(token, arg, mnt_opts); + kfree(arg); + arg = NULL; + if (unlikely(rc)) { + goto free_opt; + } + } else { + if (!first) { // copy with preceding comma + from--; + len++; + } + if (to != from) + memmove(to, from, len); + to += len; + first = false; + } + if (!from[len]) + break; + from += len + 1; + } + *to = '\0'; + return 0; + +free_opt: + if (*mnt_opts) { + selinux_free_mnt_opts(*mnt_opts); + *mnt_opts = NULL; + } + return rc; +} + +static int selinux_sb_mnt_opts_compat(struct super_block *sb, void *mnt_opts) +{ + struct selinux_mnt_opts *opts = mnt_opts; + struct superblock_security_struct *sbsec = selinux_superblock(sb); + + /* + * Superblock not initialized (i.e. no options) - reject if any + * options specified, otherwise accept. + */ + if (!(sbsec->flags & SE_SBINITIALIZED)) + return opts ? 1 : 0; + + /* + * Superblock initialized and no options specified - reject if + * superblock has any options set, otherwise accept. + */ + if (!opts) + return (sbsec->flags & SE_MNTMASK) ? 1 : 0; + + if (opts->fscontext_sid) { + if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid, + opts->fscontext_sid)) + return 1; + } + if (opts->context_sid) { + if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid, + opts->context_sid)) + return 1; + } + if (opts->rootcontext_sid) { + struct inode_security_struct *root_isec; + + root_isec = backing_inode_security(sb->s_root); + if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid, + opts->rootcontext_sid)) + return 1; + } + if (opts->defcontext_sid) { + if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid, + opts->defcontext_sid)) + return 1; + } + return 0; +} + +static int selinux_sb_remount(struct super_block *sb, void *mnt_opts) +{ + struct selinux_mnt_opts *opts = mnt_opts; + struct superblock_security_struct *sbsec = selinux_superblock(sb); + + if (!(sbsec->flags & SE_SBINITIALIZED)) + return 0; + + if (!opts) + return 0; + + if (opts->fscontext_sid) { + if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid, + opts->fscontext_sid)) + goto out_bad_option; + } + if (opts->context_sid) { + if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid, + opts->context_sid)) + goto out_bad_option; + } + if (opts->rootcontext_sid) { + struct inode_security_struct *root_isec; + root_isec = backing_inode_security(sb->s_root); + if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid, + opts->rootcontext_sid)) + goto out_bad_option; + } + if (opts->defcontext_sid) { + if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid, + opts->defcontext_sid)) + goto out_bad_option; + } + return 0; + +out_bad_option: + pr_warn("SELinux: unable to change security options " + "during remount (dev %s, type=%s)\n", sb->s_id, + sb->s_type->name); + return -EINVAL; +} + +static int selinux_sb_kern_mount(const struct super_block *sb) +{ + const struct cred *cred = current_cred(); + struct common_audit_data ad; + + ad.type = LSM_AUDIT_DATA_DENTRY; + ad.u.dentry = sb->s_root; + return superblock_has_perm(cred, sb, FILESYSTEM__MOUNT, &ad); +} + +static int selinux_sb_statfs(struct dentry *dentry) +{ + const struct cred *cred = current_cred(); + struct common_audit_data ad; + + ad.type = LSM_AUDIT_DATA_DENTRY; + ad.u.dentry = dentry->d_sb->s_root; + return superblock_has_perm(cred, dentry->d_sb, FILESYSTEM__GETATTR, &ad); +} + +static int selinux_mount(const char *dev_name, + const struct path *path, + const char *type, + unsigned long flags, + void *data) +{ + const struct cred *cred = current_cred(); + + if (flags & MS_REMOUNT) + return superblock_has_perm(cred, path->dentry->d_sb, + FILESYSTEM__REMOUNT, NULL); + else + return path_has_perm(cred, path, FILE__MOUNTON); +} + +static int selinux_move_mount(const struct path *from_path, + const struct path *to_path) +{ + const struct cred *cred = current_cred(); + + return path_has_perm(cred, to_path, FILE__MOUNTON); +} + +static int selinux_umount(struct vfsmount *mnt, int flags) +{ + const struct cred *cred = current_cred(); + + return superblock_has_perm(cred, mnt->mnt_sb, + FILESYSTEM__UNMOUNT, NULL); +} + +static int selinux_fs_context_submount(struct fs_context *fc, + struct super_block *reference) +{ + const struct superblock_security_struct *sbsec = selinux_superblock(reference); + struct selinux_mnt_opts *opts; + + /* + * Ensure that fc->security remains NULL when no options are set + * as expected by selinux_set_mnt_opts(). + */ + if (!(sbsec->flags & (FSCONTEXT_MNT|CONTEXT_MNT|DEFCONTEXT_MNT))) + return 0; + + opts = kzalloc_obj(*opts); + if (!opts) + return -ENOMEM; + + if (sbsec->flags & FSCONTEXT_MNT) + opts->fscontext_sid = sbsec->sid; + if (sbsec->flags & CONTEXT_MNT) + opts->context_sid = sbsec->mntpoint_sid; + if (sbsec->flags & DEFCONTEXT_MNT) + opts->defcontext_sid = sbsec->def_sid; + fc->security = opts; + return 0; +} + +static int selinux_fs_context_dup(struct fs_context *fc, + struct fs_context *src_fc) +{ + const struct selinux_mnt_opts *src = src_fc->security; + + if (!src) + return 0; + + fc->security = kmemdup(src, sizeof(*src), GFP_KERNEL); + return fc->security ? 0 : -ENOMEM; +} + +static const struct fs_parameter_spec selinux_fs_parameters[] = { + fsparam_string(CONTEXT_STR, Opt_context), + fsparam_string(DEFCONTEXT_STR, Opt_defcontext), + fsparam_string(FSCONTEXT_STR, Opt_fscontext), + fsparam_string(ROOTCONTEXT_STR, Opt_rootcontext), + fsparam_flag (SECLABEL_STR, Opt_seclabel), + {} +}; + +static int selinux_fs_context_parse_param(struct fs_context *fc, + struct fs_parameter *param) +{ + struct fs_parse_result result; + int opt; + + opt = fs_parse(fc, selinux_fs_parameters, param, &result); + if (opt < 0) + return opt; + + return selinux_add_opt(opt, param->string, &fc->security); +} + +/* inode security operations */ + +static int selinux_inode_alloc_security(struct inode *inode) +{ + struct inode_security_struct *isec = selinux_inode(inode); + u32 sid = current_sid(); + + spin_lock_init(&isec->lock); + INIT_LIST_HEAD(&isec->list); + isec->inode = inode; + isec->sid = SECINITSID_UNLABELED; + isec->sclass = SECCLASS_FILE; + isec->task_sid = sid; + isec->initialized = LABEL_INVALID; + + return 0; +} + +static void selinux_inode_free_security(struct inode *inode) +{ + inode_free_security(inode); +} + +static int selinux_dentry_init_security(struct dentry *dentry, int mode, + const struct qstr *name, + const char **xattr_name, + struct lsm_context *cp) +{ + u32 newsid; + int rc; + + rc = selinux_determine_inode_label(selinux_cred(current_cred()), + d_inode(dentry->d_parent), name, + inode_mode_to_security_class(mode), + &newsid); + if (rc) + return rc; + + if (xattr_name) + *xattr_name = XATTR_NAME_SELINUX; + + cp->id = LSM_ID_SELINUX; + return security_sid_to_context(newsid, &cp->context, &cp->len); +} + +static int selinux_dentry_create_files_as(struct dentry *dentry, int mode, + const struct qstr *name, + const struct cred *old, + struct cred *new) +{ + u32 newsid; + int rc; + struct cred_security_struct *crsec; + + rc = selinux_determine_inode_label(selinux_cred(old), + d_inode(dentry->d_parent), name, + inode_mode_to_security_class(mode), + &newsid); + if (rc) + return rc; + + crsec = selinux_cred(new); + crsec->create_sid = newsid; + return 0; +} + +static int selinux_inode_init_security(struct inode *inode, struct inode *dir, + const struct qstr *qstr, + struct xattr *xattrs, int *xattr_count) +{ + const struct cred_security_struct *crsec = selinux_cred(current_cred()); + struct superblock_security_struct *sbsec; + struct xattr *xattr; + u32 newsid, clen; + u16 newsclass; + int rc; + char *context; + + sbsec = selinux_superblock(dir->i_sb); + + if (!selinux_initialized() || + !(sbsec->flags & SBLABEL_MNT)) + return -EOPNOTSUPP; + + newsid = crsec->create_sid; + newsclass = inode_mode_to_security_class(inode->i_mode); + rc = selinux_determine_inode_label(crsec, dir, qstr, newsclass, &newsid); + if (rc) + return rc; + + /* Possibly defer initialization to selinux_complete_init. */ + if (sbsec->flags & SE_SBINITIALIZED) { + struct inode_security_struct *isec = selinux_inode(inode); + isec->sclass = newsclass; + isec->sid = newsid; + isec->initialized = LABEL_INITIALIZED; + } + + xattr = lsm_get_xattr_slot(xattrs, xattr_count); + if (xattr) { + rc = security_sid_to_context_force(newsid, + &context, &clen); + if (rc) + return rc; + xattr->value = context; + xattr->value_len = clen; + xattr->name = XATTR_SELINUX_SUFFIX; + } + + return 0; +} + +static int selinux_inode_init_security_anon(struct inode *inode, + const struct qstr *name, + const struct inode *context_inode) +{ + u32 sid = current_sid(); + struct common_audit_data ad; + struct inode_security_struct *isec; + int rc; + bool is_memfd = false; + + if (unlikely(!selinux_initialized())) + return 0; + + if (name != NULL && name->name != NULL && + !strcmp(name->name, MEMFD_ANON_NAME)) { + if (!selinux_policycap_memfd_class()) + return 0; + is_memfd = true; + } + + isec = selinux_inode(inode); + + /* + * We only get here once per ephemeral inode. The inode has + * been initialized via inode_alloc_security but is otherwise + * untouched. + */ + + if (context_inode) { + struct inode_security_struct *context_isec = + selinux_inode(context_inode); + if (context_isec->initialized != LABEL_INITIALIZED) { + pr_err("SELinux: context_inode is not initialized\n"); + return -EACCES; + } + + isec->sclass = context_isec->sclass; + isec->sid = context_isec->sid; + } else { + if (is_memfd) + isec->sclass = SECCLASS_MEMFD_FILE; + else + isec->sclass = SECCLASS_ANON_INODE; + rc = security_transition_sid( + sid, sid, + isec->sclass, name, &isec->sid); + if (rc) + return rc; + } + + isec->initialized = LABEL_INITIALIZED; + /* + * Now that we've initialized security, check whether we're + * allowed to actually create this type of anonymous inode. + */ + + ad.type = LSM_AUDIT_DATA_ANONINODE; + ad.u.anonclass = name ? (const char *)name->name : "?"; + + return avc_has_perm(sid, + isec->sid, + isec->sclass, + FILE__CREATE, + &ad); +} + +static int selinux_inode_create(struct inode *dir, struct dentry *dentry, umode_t mode) +{ + return may_create(dir, dentry, SECCLASS_FILE); +} + +static int selinux_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry) +{ + return may_link(dir, old_dentry, MAY_LINK); +} + +static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry) +{ + return may_link(dir, dentry, MAY_UNLINK); +} + +static int selinux_inode_symlink(struct inode *dir, struct dentry *dentry, const char *name) +{ + return may_create(dir, dentry, SECCLASS_LNK_FILE); +} + +static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, umode_t mask) +{ + return may_create(dir, dentry, SECCLASS_DIR); +} + +static int selinux_inode_rmdir(struct inode *dir, struct dentry *dentry) +{ + return may_link(dir, dentry, MAY_RMDIR); +} + +static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev) +{ + return may_create(dir, dentry, inode_mode_to_security_class(mode)); +} + +static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry, + struct inode *new_inode, struct dentry *new_dentry) +{ + return may_rename(old_inode, old_dentry, new_inode, new_dentry); +} + +static int selinux_inode_readlink(struct dentry *dentry) +{ + const struct cred *cred = current_cred(); + + return dentry_has_perm(cred, dentry, FILE__READ); +} + +static int selinux_inode_follow_link(struct dentry *dentry, struct inode *inode, + bool rcu) +{ + struct common_audit_data ad; + struct inode_security_struct *isec; + u32 sid = current_sid(); + + ad.type = LSM_AUDIT_DATA_DENTRY; + ad.u.dentry = dentry; + isec = inode_security_rcu(inode, rcu); + if (IS_ERR(isec)) + return PTR_ERR(isec); + + return avc_has_perm(sid, isec->sid, isec->sclass, FILE__READ, &ad); +} + +static noinline int audit_inode_permission(struct inode *inode, + u32 perms, u32 audited, u32 denied, + int result) +{ + struct common_audit_data ad; + struct inode_security_struct *isec = selinux_inode(inode); + + ad.type = LSM_AUDIT_DATA_INODE; + ad.u.inode = inode; + + return slow_avc_audit(current_sid(), isec->sid, isec->sclass, perms, + audited, denied, result, &ad); +} + +/** + * task_avdcache_reset - Reset the task's AVD cache + * @tsec: the task's security state + * + * Clear the task's AVD cache in @tsec and reset it to the current policy's + * and task's info. + */ +static inline void task_avdcache_reset(struct task_security_struct *tsec) +{ + memset(&tsec->avdcache.dir, 0, sizeof(tsec->avdcache.dir)); + tsec->avdcache.sid = current_sid(); + tsec->avdcache.seqno = avc_policy_seqno(); + tsec->avdcache.dir_spot = TSEC_AVDC_DIR_SIZE - 1; +} + +/** + * task_avdcache_search - Search the task's AVD cache + * @tsec: the task's security state + * @isec: the inode to search for in the cache + * @avdc: matching avd cache entry returned to the caller + * + * Search @tsec for a AVD cache entry that matches @isec and return it to the + * caller via @avdc. Returns 0 if a match is found, negative values otherwise. + */ +static inline int task_avdcache_search(struct task_security_struct *tsec, + struct inode_security_struct *isec, + struct avdc_entry **avdc) +{ + int orig, iter; + + /* focused on path walk optimization, only cache directories */ + if (isec->sclass != SECCLASS_DIR) + return -ENOENT; + + if (unlikely(current_sid() != tsec->avdcache.sid || + tsec->avdcache.seqno != avc_policy_seqno())) { + task_avdcache_reset(tsec); + return -ENOENT; + } + + orig = iter = tsec->avdcache.dir_spot; + do { + if (tsec->avdcache.dir[iter].isid == isec->sid) { + /* cache hit */ + tsec->avdcache.dir_spot = iter; + *avdc = &tsec->avdcache.dir[iter]; + return 0; + } + iter = (iter - 1) & (TSEC_AVDC_DIR_SIZE - 1); + } while (iter != orig); + + return -ENOENT; +} + +/** + * task_avdcache_update - Update the task's AVD cache + * @tsec: the task's security state + * @isec: the inode associated with the cache entry + * @avd: the AVD to cache + * + * Update the AVD cache in @tsec with the @avd info associated + * with @isec. + */ +static inline void task_avdcache_update(struct task_security_struct *tsec, + struct inode_security_struct *isec, + struct av_decision *avd) +{ + int spot; + + /* focused on path walk optimization, only cache directories */ + if (isec->sclass != SECCLASS_DIR) + return; + + /* update cache */ + spot = (tsec->avdcache.dir_spot + 1) & (TSEC_AVDC_DIR_SIZE - 1); + tsec->avdcache.dir_spot = spot; + tsec->avdcache.dir[spot].isid = isec->sid; + tsec->avdcache.dir[spot].avd = *avd; + tsec->avdcache.permissive_neveraudit = + (avd->flags == (AVD_FLAGS_PERMISSIVE|AVD_FLAGS_NEVERAUDIT)); +} + +/** + * selinux_inode_permission - Check if the current task can access an inode + * @inode: the inode that is being accessed + * @requested: the accesses being requested + * + * Check if the current task is allowed to access @inode according to + * @requested. Returns 0 if allowed, negative values otherwise. + */ +static int selinux_inode_permission(struct inode *inode, int requested) +{ + int mask; + u32 perms; + u32 sid = current_sid(); + struct task_security_struct *tsec; + struct inode_security_struct *isec; + struct avdc_entry *avdc; + struct av_decision avd, *avdp = &avd; + int rc, rc2; + u32 audited, denied; + + mask = requested & (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND); + + /* No permission to check. Existence test. */ + if (!mask) + return 0; + + tsec = selinux_task(current); + if (task_avdcache_permnoaudit(tsec, sid)) + return 0; + + isec = inode_security_rcu(inode, requested & MAY_NOT_BLOCK); + if (IS_ERR(isec)) + return PTR_ERR(isec); + perms = file_mask_to_av(inode->i_mode, mask); + + rc = task_avdcache_search(tsec, isec, &avdc); + if (likely(!rc)) { + /* Cache hit. */ + avdp = &avdc->avd; + denied = perms & ~avdp->allowed; + if (unlikely(denied) && enforcing_enabled() && + !(avdp->flags & AVD_FLAGS_PERMISSIVE)) + rc = -EACCES; + } else { + /* Cache miss. */ + rc = avc_has_perm_noaudit(sid, isec->sid, isec->sclass, + perms, 0, avdp); + task_avdcache_update(tsec, isec, avdp); + } + + audited = avc_audit_required(perms, avdp, rc, + (requested & MAY_ACCESS) ? + FILE__AUDIT_ACCESS : 0, &denied); + if (likely(!audited)) + return rc; + + rc2 = audit_inode_permission(inode, perms, audited, denied, rc); + if (rc2) + return rc2; + + return rc; +} + +static int selinux_inode_setattr(struct mnt_idmap *idmap, struct dentry *dentry, + struct iattr *iattr) +{ + const struct cred *cred = current_cred(); + struct inode *inode = d_backing_inode(dentry); + unsigned int ia_valid = iattr->ia_valid; + u32 av = FILE__WRITE; + + /* ATTR_FORCE is just used for ATTR_KILL_S[UG]ID. */ + if (ia_valid & ATTR_FORCE) { + ia_valid &= ~(ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_MODE | + ATTR_FORCE); + if (!ia_valid) + return 0; + } + + if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID | + ATTR_ATIME_SET | ATTR_MTIME_SET | ATTR_TIMES_SET)) + return dentry_has_perm(cred, dentry, FILE__SETATTR); + + if (selinux_policycap_openperm() && + inode->i_sb->s_magic != SOCKFS_MAGIC && + (ia_valid & ATTR_SIZE) && + !(ia_valid & ATTR_FILE)) + av |= FILE__OPEN; + + return dentry_has_perm(cred, dentry, av); +} + +static int selinux_inode_getattr(const struct path *path) +{ + struct task_security_struct *tsec; + + tsec = selinux_task(current); + + if (task_avdcache_permnoaudit(tsec, current_sid())) + return 0; + + return path_has_perm(current_cred(), path, FILE__GETATTR); +} + +static bool has_cap_mac_admin(bool audit) +{ + const struct cred *cred = current_cred(); + unsigned int opts = audit ? CAP_OPT_NONE : CAP_OPT_NOAUDIT; + + if (cap_capable(cred, &init_user_ns, CAP_MAC_ADMIN, opts)) + return false; + if (cred_has_capability(cred, CAP_MAC_ADMIN, opts, true)) + return false; + return true; +} + +/** + * selinux_inode_xattr_skipcap - Skip the xattr capability checks? + * @name: name of the xattr + * + * Returns 1 to indicate that SELinux "owns" the access control rights to xattrs + * named @name; the LSM layer should avoid enforcing any traditional + * capability based access controls on this xattr. Returns 0 to indicate that + * SELinux does not "own" the access control rights to xattrs named @name and is + * deferring to the LSM layer for further access controls, including capability + * based controls. + */ +static int selinux_inode_xattr_skipcap(const char *name) +{ + /* require capability check if not a selinux xattr */ + return !strcmp(name, XATTR_NAME_SELINUX); +} + +static int selinux_inode_setxattr(struct mnt_idmap *idmap, + struct dentry *dentry, const char *name, + const void *value, size_t size, int flags) +{ + struct inode *inode = d_backing_inode(dentry); + struct inode_security_struct *isec; + struct superblock_security_struct *sbsec; + struct common_audit_data ad; + u32 newsid, sid = current_sid(); + int rc = 0; + + /* if not a selinux xattr, only check the ordinary setattr perm */ + if (strcmp(name, XATTR_NAME_SELINUX)) + return dentry_has_perm(current_cred(), dentry, FILE__SETATTR); + + if (!selinux_initialized()) + return (inode_owner_or_capable(idmap, inode) ? 0 : -EPERM); + + sbsec = selinux_superblock(inode->i_sb); + if (!(sbsec->flags & SBLABEL_MNT)) + return -EOPNOTSUPP; + + if (!inode_owner_or_capable(idmap, inode)) + return -EPERM; + + ad.type = LSM_AUDIT_DATA_DENTRY; + ad.u.dentry = dentry; + + isec = backing_inode_security(dentry); + rc = avc_has_perm(sid, isec->sid, isec->sclass, + FILE__RELABELFROM, &ad); + if (rc) + return rc; + + rc = security_context_to_sid(value, size, &newsid, + GFP_KERNEL); + if (rc == -EINVAL) { + if (!has_cap_mac_admin(true)) { + struct audit_buffer *ab; + size_t audit_size; + + /* We strip a nul only if it is at the end, otherwise the + * context contains a nul and we should audit that */ + if (value) { + const char *str = value; + + if (str[size - 1] == '\0') + audit_size = size - 1; + else + audit_size = size; + } else { + audit_size = 0; + } + ab = audit_log_start(audit_context(), + GFP_ATOMIC, AUDIT_SELINUX_ERR); + if (!ab) + return rc; + audit_log_format(ab, "op=setxattr invalid_context="); + audit_log_n_untrustedstring(ab, value, audit_size); + audit_log_end(ab); + + return rc; + } + rc = security_context_to_sid_force(value, + size, &newsid); + } + if (rc) + return rc; + + rc = avc_has_perm(sid, newsid, isec->sclass, + FILE__RELABELTO, &ad); + if (rc) + return rc; + + rc = security_validate_transition(isec->sid, newsid, + sid, isec->sclass); + if (rc) + return rc; + + return avc_has_perm(newsid, + sbsec->sid, + SECCLASS_FILESYSTEM, + FILESYSTEM__ASSOCIATE, + &ad); +} + +static int selinux_inode_set_acl(struct mnt_idmap *idmap, + struct dentry *dentry, const char *acl_name, + struct posix_acl *kacl) +{ + return dentry_has_perm(current_cred(), dentry, FILE__SETATTR); +} + +static int selinux_inode_get_acl(struct mnt_idmap *idmap, + struct dentry *dentry, const char *acl_name) +{ + return dentry_has_perm(current_cred(), dentry, FILE__GETATTR); +} + +static int selinux_inode_remove_acl(struct mnt_idmap *idmap, + struct dentry *dentry, const char *acl_name) +{ + return dentry_has_perm(current_cred(), dentry, FILE__SETATTR); +} + +static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name, + const void *value, size_t size, + int flags) +{ + struct inode *inode = d_backing_inode(dentry); + struct inode_security_struct *isec; + u32 newsid; + int rc; + + if (strcmp(name, XATTR_NAME_SELINUX)) { + /* Not an attribute we recognize, so nothing to do. */ + return; + } + + if (!selinux_initialized()) { + /* If we haven't even been initialized, then we can't validate + * against a policy, so leave the label as invalid. It may + * resolve to a valid label on the next revalidation try if + * we've since initialized. + */ + return; + } + + rc = security_context_to_sid_force(value, size, + &newsid); + if (rc) { + pr_err("SELinux: unable to map context to SID" + "for (%s, %llu), rc=%d\n", + inode->i_sb->s_id, inode->i_ino, -rc); + return; + } + + isec = backing_inode_security(dentry); + spin_lock(&isec->lock); + isec->sclass = inode_mode_to_security_class(inode->i_mode); + isec->sid = newsid; + isec->initialized = LABEL_INITIALIZED; + spin_unlock(&isec->lock); +} + +static int selinux_inode_getxattr(struct dentry *dentry, const char *name) +{ + const struct cred *cred = current_cred(); + + return dentry_has_perm(cred, dentry, FILE__GETATTR); +} + +static int selinux_inode_listxattr(struct dentry *dentry) +{ + const struct cred *cred = current_cred(); + + return dentry_has_perm(cred, dentry, FILE__GETATTR); +} + +static int selinux_inode_removexattr(struct mnt_idmap *idmap, + struct dentry *dentry, const char *name) +{ + /* if not a selinux xattr, only check the ordinary setattr perm */ + if (strcmp(name, XATTR_NAME_SELINUX)) + return dentry_has_perm(current_cred(), dentry, FILE__SETATTR); + + if (!selinux_initialized()) + return 0; + + /* No one is allowed to remove a SELinux security label. + You can change the label, but all data must be labeled. */ + return -EACCES; +} + +static int selinux_inode_file_setattr(struct dentry *dentry, + struct file_kattr *fa) +{ + return dentry_has_perm(current_cred(), dentry, FILE__SETATTR); +} + +static int selinux_inode_file_getattr(struct dentry *dentry, + struct file_kattr *fa) +{ + return dentry_has_perm(current_cred(), dentry, FILE__GETATTR); +} + +static int selinux_path_notify(const struct path *path, u64 mask, + unsigned int obj_type) +{ + int ret; + u32 perm; + + struct common_audit_data ad; + + ad.type = LSM_AUDIT_DATA_PATH; + ad.u.path = *path; + + /* + * Set permission needed based on the type of mark being set. + * Performs an additional check for sb watches. + */ + switch (obj_type) { + case FSNOTIFY_OBJ_TYPE_VFSMOUNT: + perm = FILE__WATCH_MOUNT; + break; + case FSNOTIFY_OBJ_TYPE_SB: + perm = FILE__WATCH_SB; + ret = superblock_has_perm(current_cred(), path->dentry->d_sb, + FILESYSTEM__WATCH, &ad); + if (ret) + return ret; + break; + case FSNOTIFY_OBJ_TYPE_INODE: + perm = FILE__WATCH; + break; + case FSNOTIFY_OBJ_TYPE_MNTNS: + perm = FILE__WATCH_MOUNTNS; + break; + default: + return -EINVAL; + } + + /* blocking watches require the file:watch_with_perm permission */ + if (mask & (ALL_FSNOTIFY_PERM_EVENTS)) + perm |= FILE__WATCH_WITH_PERM; + + /* watches on read-like events need the file:watch_reads permission */ + if (mask & (FS_ACCESS | FS_ACCESS_PERM | FS_PRE_ACCESS | + FS_CLOSE_NOWRITE)) + perm |= FILE__WATCH_READS; + + return path_has_perm(current_cred(), path, perm); +} + +/* + * Copy the inode security context value to the user. + * + * Permission check is handled by selinux_inode_getxattr hook. + */ +static int selinux_inode_getsecurity(struct mnt_idmap *idmap, + struct inode *inode, const char *name, + void **buffer, bool alloc) +{ + u32 size; + int error; + char *context = NULL; + struct inode_security_struct *isec; + + /* + * If we're not initialized yet, then we can't validate contexts, so + * just let vfs_getxattr fall back to using the on-disk xattr. + */ + if (!selinux_initialized() || + strcmp(name, XATTR_SELINUX_SUFFIX)) + return -EOPNOTSUPP; + + /* + * If the caller has CAP_MAC_ADMIN, then get the raw context + * value even if it is not defined by current policy; otherwise, + * use the in-core value under current policy. + * Use the non-auditing forms of the permission checks since + * getxattr may be called by unprivileged processes commonly + * and lack of permission just means that we fall back to the + * in-core context value, not a denial. + */ + isec = inode_security(inode); + if (has_cap_mac_admin(false)) + error = security_sid_to_context_force(isec->sid, &context, + &size); + else + error = security_sid_to_context(isec->sid, + &context, &size); + if (error) + return error; + error = size; + if (alloc) { + *buffer = context; + goto out_nofree; + } + kfree(context); +out_nofree: + return error; +} + +static int selinux_inode_setsecurity(struct inode *inode, const char *name, + const void *value, size_t size, int flags) +{ + struct inode_security_struct *isec = inode_security_novalidate(inode); + struct superblock_security_struct *sbsec; + u32 newsid; + int rc; + + if (strcmp(name, XATTR_SELINUX_SUFFIX)) + return -EOPNOTSUPP; + + sbsec = selinux_superblock(inode->i_sb); + if (!(sbsec->flags & SBLABEL_MNT)) + return -EOPNOTSUPP; + + if (!value || !size) + return -EACCES; + + rc = security_context_to_sid(value, size, &newsid, + GFP_KERNEL); + if (rc) + return rc; + + spin_lock(&isec->lock); + isec->sclass = inode_mode_to_security_class(inode->i_mode); + isec->sid = newsid; + isec->initialized = LABEL_INITIALIZED; + spin_unlock(&isec->lock); + return 0; +} + +static int selinux_inode_listsecurity(struct inode *inode, char **buffer, + ssize_t *remaining_size) +{ + if (!selinux_initialized()) + return 0; + return xattr_list_one(buffer, remaining_size, XATTR_NAME_SELINUX); +} + +static void selinux_inode_getlsmprop(struct inode *inode, struct lsm_prop *prop) +{ + struct inode_security_struct *isec = inode_security_novalidate(inode); + + prop->selinux.secid = isec->sid; +} + +static int selinux_inode_copy_up(struct dentry *src, struct cred **new) +{ + struct lsm_prop prop; + struct cred_security_struct *crsec; + struct cred *new_creds = *new; + + if (new_creds == NULL) { + new_creds = prepare_creds(); + if (!new_creds) + return -ENOMEM; + } + + crsec = selinux_cred(new_creds); + /* Get label from overlay inode and set it in create_sid */ + selinux_inode_getlsmprop(d_inode(src), &prop); + crsec->create_sid = prop.selinux.secid; + *new = new_creds; + return 0; +} + +static int selinux_inode_copy_up_xattr(struct dentry *dentry, const char *name) +{ + /* The copy_up hook above sets the initial context on an inode, but we + * don't then want to overwrite it by blindly copying all the lower + * xattrs up. Instead, filter out SELinux-related xattrs following + * policy load. + */ + if (selinux_initialized() && !strcmp(name, XATTR_NAME_SELINUX)) + return -ECANCELED; /* Discard */ + /* + * Any other attribute apart from SELINUX is not claimed, supported + * by selinux. + */ + return -EOPNOTSUPP; +} + +/* kernfs node operations */ + +static int selinux_kernfs_init_security(struct kernfs_node *kn_dir, + struct kernfs_node *kn) +{ + const struct cred_security_struct *crsec = selinux_cred(current_cred()); + u32 parent_sid, newsid, clen; + int rc; + char *context; + + rc = kernfs_xattr_get(kn_dir, XATTR_NAME_SELINUX, NULL, 0); + if (rc == -ENODATA) + return 0; + else if (rc < 0) + return rc; + + clen = (u32)rc; + context = kmalloc(clen, GFP_KERNEL); + if (!context) + return -ENOMEM; + + rc = kernfs_xattr_get(kn_dir, XATTR_NAME_SELINUX, context, clen); + if (rc < 0) { + kfree(context); + return rc; + } + + rc = security_context_to_sid(context, clen, &parent_sid, + GFP_KERNEL); + kfree(context); + if (rc) + return rc; + + if (crsec->create_sid) { + newsid = crsec->create_sid; + } else { + u16 secclass = inode_mode_to_security_class(kn->mode); + const char *kn_name; + struct qstr q; + + /* kn is fresh, can't be renamed, name goes not away */ + kn_name = rcu_dereference_check(kn->name, true); + q.name = kn_name; + q.hash_len = hashlen_string(kn_dir, kn_name); + + rc = security_transition_sid(crsec->sid, + parent_sid, secclass, &q, + &newsid); + if (rc) + return rc; + } + + rc = security_sid_to_context_force(newsid, + &context, &clen); + if (rc) + return rc; + + rc = kernfs_xattr_set(kn, XATTR_NAME_SELINUX, context, clen, + XATTR_CREATE); + kfree(context); + return rc; +} + + +/* file security operations */ + +static int selinux_revalidate_file_permission(struct file *file, int mask) +{ + const struct cred *cred = current_cred(); + struct inode *inode = file_inode(file); + + /* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */ + if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE)) + mask |= MAY_APPEND; + + return file_has_perm(cred, file, + file_mask_to_av(inode->i_mode, mask)); +} + +static int selinux_file_permission(struct file *file, int mask) +{ + struct inode *inode = file_inode(file); + struct file_security_struct *fsec = selinux_file(file); + struct inode_security_struct *isec; + u32 sid = current_sid(); + + if (!mask) + /* No permission to check. Existence test. */ + return 0; + + isec = inode_security(inode); + if (sid == fsec->sid && fsec->isid == isec->sid && + fsec->pseqno == avc_policy_seqno()) + /* No change since file_open check. */ + return 0; + + return selinux_revalidate_file_permission(file, mask); +} + +static int selinux_file_alloc_security(struct file *file) +{ + struct file_security_struct *fsec = selinux_file(file); + u32 sid = current_sid(); + + fsec->sid = sid; + fsec->fown_sid = sid; + + return 0; +} + +static int selinux_backing_file_alloc(struct file *backing_file, + const struct file *user_file) +{ + struct backing_file_security_struct *bfsec; + + bfsec = selinux_backing_file(backing_file); + bfsec->uf_sid = selinux_file(user_file)->sid; + + return 0; +} + +/* + * Check whether a task has the ioctl permission and cmd + * operation to an inode. + */ +static int ioctl_has_perm(const struct cred *cred, struct file *file, + u32 requested, u16 cmd) +{ + struct common_audit_data ad; + struct file_security_struct *fsec = selinux_file(file); + struct inode *inode = file_inode(file); + struct inode_security_struct *isec; + struct lsm_ioctlop_audit ioctl; + u32 ssid = cred_sid(cred); + int rc; + u8 driver = cmd >> 8; + u8 xperm = cmd & 0xff; + + ad.type = LSM_AUDIT_DATA_IOCTL_OP; + ad.u.op = &ioctl; + ad.u.op->cmd = cmd; + ad.u.op->path = file->f_path; + + if (ssid != fsec->sid) { + rc = avc_has_perm(ssid, fsec->sid, + SECCLASS_FD, + FD__USE, + &ad); + if (rc) + goto out; + } + + if (unlikely(IS_PRIVATE(inode))) + return 0; + + isec = inode_security(inode); + rc = avc_has_extended_perms(ssid, isec->sid, isec->sclass, requested, + driver, AVC_EXT_IOCTL, xperm, &ad); +out: + return rc; +} + +static int selinux_file_ioctl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + const struct cred *cred = current_cred(); + int error = 0; + + switch (cmd) { + case FIONREAD: + case FIBMAP: + case FIGETBSZ: + case FS_IOC_GETFLAGS: + case FS_IOC_GETVERSION: + error = file_has_perm(cred, file, FILE__GETATTR); + break; + + case FS_IOC_SETFLAGS: + case FS_IOC_SETVERSION: + error = file_has_perm(cred, file, FILE__SETATTR); + break; + + /* sys_ioctl() checks */ + case FIONBIO: + case FIOASYNC: + error = file_has_perm(cred, file, 0); + break; + + case KDSKBENT: + case KDSKBSENT: + error = cred_has_capability(cred, CAP_SYS_TTY_CONFIG, + CAP_OPT_NONE, true); + break; + + case FIOCLEX: + case FIONCLEX: + if (!selinux_policycap_ioctl_skip_cloexec()) + error = ioctl_has_perm(cred, file, FILE__IOCTL, (u16) cmd); + break; + + /* default case assumes that the command will go + * to the file's ioctl() function. + */ + default: + error = ioctl_has_perm(cred, file, FILE__IOCTL, (u16) cmd); + } + return error; +} + +static int selinux_file_ioctl_compat(struct file *file, unsigned int cmd, + unsigned long arg) +{ + /* + * If we are in a 64-bit kernel running 32-bit userspace, we need to + * make sure we don't compare 32-bit flags to 64-bit flags. + */ + switch (cmd) { + case FS_IOC32_GETFLAGS: + cmd = FS_IOC_GETFLAGS; + break; + case FS_IOC32_SETFLAGS: + cmd = FS_IOC_SETFLAGS; + break; + case FS_IOC32_GETVERSION: + cmd = FS_IOC_GETVERSION; + break; + case FS_IOC32_SETVERSION: + cmd = FS_IOC_SETVERSION; + break; + default: + break; + } + + return selinux_file_ioctl(file, cmd, arg); +} + +static int default_noexec __ro_after_init; + +static int __file_map_prot_check(const struct file *file, unsigned long prot, + bool shared, bool mounter_check, + bool bf_user_file) +{ + struct inode *inode = NULL; + bool prot_exec = prot & PROT_EXEC; + bool prot_write = prot & PROT_WRITE; + + if (file) { + if (bf_user_file) + inode = d_inode(backing_file_user_path(file)->dentry); + else + inode = file_inode(file); + } + + if (!mounter_check && default_noexec && prot_exec && + (!file || IS_PRIVATE(inode) || (!shared && prot_write))) { + int rc; + u32 sid = current_sid(); + + /* + * We are making executable an anonymous mapping or a private + * file mapping that will also be writable. + */ + rc = avc_has_perm(sid, sid, SECCLASS_PROCESS, PROCESS__EXECMEM, + NULL); + if (rc) + return rc; + } + + if (file) { + const struct cred *cred = mounter_check ? + file->f_cred : current_cred(); + /* "read" always possible, "write" only if shared */ + u32 av = FILE__READ; + if (shared && prot_write) + av |= FILE__WRITE; + if (prot_exec) + av |= FILE__EXECUTE; + + return __file_has_perm(cred, file, av, bf_user_file); + } + + return 0; +} + +static inline int file_map_prot_check(const struct file *file, + unsigned long prot, bool shared, + bool mounter_check) +{ + return __file_map_prot_check(file, prot, shared, mounter_check, false); +} + +static int selinux_mmap_addr(unsigned long addr) +{ + int rc = 0; + + if (addr < CONFIG_LSM_MMAP_MIN_ADDR) { + u32 sid = current_sid(); + rc = avc_has_perm(sid, sid, SECCLASS_MEMPROTECT, + MEMPROTECT__MMAP_ZERO, NULL); + } + + return rc; +} + +static int selinux_mmap_file_common(struct file *file, unsigned long prot, + bool shared, bool mounter_check) +{ + if (file) { + int rc; + struct common_audit_data ad; + const struct cred *cred = mounter_check ? + file->f_cred : current_cred(); + + ad.type = LSM_AUDIT_DATA_FILE; + ad.u.file = file; + rc = inode_has_perm(cred, file_inode(file), FILE__MAP, &ad); + if (rc) + return rc; + } + + return file_map_prot_check(file, prot, shared, mounter_check); +} + +static int selinux_mmap_file(struct file *file, + unsigned long reqprot __always_unused, + unsigned long prot, unsigned long flags) +{ + return selinux_mmap_file_common(file, prot, + (flags & MAP_TYPE) == MAP_SHARED, + false); +} + +/** + * selinux_mmap_backing_file - Check mmap permissions on a backing file + * @vma: memory region + * @backing_file: stacked filesystem backing file + * @user_file: user visible file + * + * This is called after selinux_mmap_file() on stacked filesystems, and it + * is this function's responsibility to verify access to @backing_file and + * setup the SELinux state for possible later use in the mprotect() code path. + * + * By the time this function is called, mmap() access to @user_file has already + * been authorized and @vma->vm_file has been set to point to @backing_file. + * + * Return zero on success, negative values otherwise. + */ +static int selinux_mmap_backing_file(struct vm_area_struct *vma, + struct file *backing_file, + struct file *user_file __always_unused) +{ + unsigned long prot = 0; + + /* translate vma->vm_flags perms into PROT perms */ + if (vma->vm_flags & VM_READ) + prot |= PROT_READ; + if (vma->vm_flags & VM_WRITE) + prot |= PROT_WRITE; + if (vma->vm_flags & VM_EXEC) + prot |= PROT_EXEC; + + return selinux_mmap_file_common(backing_file, prot, + vma->vm_flags & VM_SHARED, + true); +} + +static int selinux_file_mprotect(struct vm_area_struct *vma, + unsigned long reqprot __always_unused, + unsigned long prot) +{ + int rc; + const struct cred *cred = current_cred(); + u32 sid = cred_sid(cred); + const struct file *file = vma->vm_file; + bool backing_file; + bool shared = vma->vm_flags & VM_SHARED; + + /* check if we need to trigger the "backing files are awful" mode */ + backing_file = file && (file->f_mode & FMODE_BACKING); + + if (default_noexec && + (prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) { + /* + * We don't use the vma_is_initial_heap() helper as it has + * a history of problems and is currently broken on systems + * where there is no heap, e.g. brk == start_brk. Before + * replacing the conditional below with vma_is_initial_heap(), + * or something similar, please ensure that the logic is the + * same as what we have below or you have tested every possible + * corner case you can think to test. + */ + if (vma->vm_start >= vma->vm_mm->start_brk && + vma->vm_end <= vma->vm_mm->brk) { + rc = avc_has_perm(sid, sid, SECCLASS_PROCESS, + PROCESS__EXECHEAP, NULL); + if (rc) + return rc; + } else if (!file && (vma_is_initial_stack(vma) || + vma_is_stack_for_current(vma))) { + rc = avc_has_perm(sid, sid, SECCLASS_PROCESS, + PROCESS__EXECSTACK, NULL); + if (rc) + return rc; + } else if (file && vma->anon_vma) { + /* + * We are making executable a file mapping that has + * had some COW done. Since pages might have been + * written, check ability to execute the possibly + * modified content. This typically should only + * occur for text relocations. + */ + rc = __file_has_perm(cred, file, FILE__EXECMOD, + backing_file); + if (rc) + return rc; + if (backing_file) { + rc = file_has_perm(file->f_cred, file, + FILE__EXECMOD); + if (rc) + return rc; + } + } + } + + rc = __file_map_prot_check(file, prot, shared, false, backing_file); + if (rc) + return rc; + if (backing_file) { + rc = file_map_prot_check(file, prot, shared, true); + if (rc) + return rc; + } + + return 0; +} + +static int selinux_file_lock(struct file *file, unsigned int cmd) +{ + const struct cred *cred = current_cred(); + + return file_has_perm(cred, file, FILE__LOCK); +} + +static int selinux_file_fcntl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + const struct cred *cred = current_cred(); + int err = 0; + + switch (cmd) { + case F_SETFL: + if ((file->f_flags & O_APPEND) && !(arg & O_APPEND)) { + err = file_has_perm(cred, file, FILE__WRITE); + break; + } + fallthrough; + case F_SETOWN: + case F_SETSIG: + case F_GETFL: + case F_GETOWN: + case F_GETSIG: + case F_GETOWNER_UIDS: + /* Just check FD__USE permission */ + err = file_has_perm(cred, file, 0); + break; + case F_GETLK: + case F_SETLK: + case F_SETLKW: + case F_OFD_GETLK: + case F_OFD_SETLK: + case F_OFD_SETLKW: +#if BITS_PER_LONG == 32 + case F_GETLK64: + case F_SETLK64: + case F_SETLKW64: +#endif + err = file_has_perm(cred, file, FILE__LOCK); + break; + } + + return err; +} + +static void selinux_file_set_fowner(struct file *file) +{ + struct file_security_struct *fsec; + + fsec = selinux_file(file); + fsec->fown_sid = current_sid(); +} + +static int selinux_file_send_sigiotask(struct task_struct *tsk, + struct fown_struct *fown, int signum) +{ + struct file *file; + u32 sid = task_sid_obj(tsk); + u32 perm; + struct file_security_struct *fsec; + + /* struct fown_struct is never outside the context of a struct file */ + file = fown->file; + + fsec = selinux_file(file); + + if (!signum) + perm = signal_to_av(SIGIO); /* as per send_sigio_to_task */ + else + perm = signal_to_av(signum); + + return avc_has_perm(fsec->fown_sid, sid, + SECCLASS_PROCESS, perm, NULL); +} + +static int selinux_file_receive(struct file *file) +{ + const struct cred *cred = current_cred(); + + return file_has_perm(cred, file, file_to_av(file)); +} + +static int selinux_file_open(struct file *file) +{ + struct file_security_struct *fsec; + struct inode_security_struct *isec; + + fsec = selinux_file(file); + isec = inode_security(file_inode(file)); + /* + * Save inode label and policy sequence number + * at open-time so that selinux_file_permission + * can determine whether revalidation is necessary. + * Task label is already saved in the file security + * struct as its SID. + */ + fsec->isid = isec->sid; + fsec->pseqno = avc_policy_seqno(); + /* + * Since the inode label or policy seqno may have changed + * between the selinux_inode_permission check and the saving + * of state above, recheck that access is still permitted. + * Otherwise, access might never be revalidated against the + * new inode label or new policy. + * This check is not redundant - do not remove. + */ + return file_path_has_perm(file->f_cred, file, open_file_to_av(file)); +} + +/* task security operations */ + +static int selinux_task_alloc(struct task_struct *task, + u64 clone_flags) +{ + u32 sid = current_sid(); + struct task_security_struct *old_tsec = selinux_task(current); + struct task_security_struct *new_tsec = selinux_task(task); + + *new_tsec = *old_tsec; + return avc_has_perm(sid, sid, SECCLASS_PROCESS, PROCESS__FORK, NULL); +} + +/* + * prepare a new set of credentials for modification + */ +static int selinux_cred_prepare(struct cred *new, const struct cred *old, + gfp_t gfp) +{ + const struct cred_security_struct *old_crsec = selinux_cred(old); + struct cred_security_struct *crsec = selinux_cred(new); + + *crsec = *old_crsec; + return 0; +} + +/* + * transfer the SELinux data to a blank set of creds + */ +static void selinux_cred_transfer(struct cred *new, const struct cred *old) +{ + const struct cred_security_struct *old_crsec = selinux_cred(old); + struct cred_security_struct *crsec = selinux_cred(new); + + *crsec = *old_crsec; +} + +static void selinux_cred_getsecid(const struct cred *c, u32 *secid) +{ + *secid = cred_sid(c); +} + +static void selinux_cred_getlsmprop(const struct cred *c, struct lsm_prop *prop) +{ + prop->selinux.secid = cred_sid(c); +} + +/* + * set the security data for a kernel service + * - all the creation contexts are set to unlabelled + */ +static int selinux_kernel_act_as(struct cred *new, u32 secid) +{ + struct cred_security_struct *crsec = selinux_cred(new); + u32 sid = current_sid(); + int ret; + + ret = avc_has_perm(sid, secid, + SECCLASS_KERNEL_SERVICE, + KERNEL_SERVICE__USE_AS_OVERRIDE, + NULL); + if (ret == 0) { + crsec->sid = secid; + crsec->create_sid = 0; + crsec->keycreate_sid = 0; + crsec->sockcreate_sid = 0; + } + return ret; +} + +/* + * set the file creation context in a security record to the same as the + * objective context of the specified inode + */ +static int selinux_kernel_create_files_as(struct cred *new, struct inode *inode) +{ + struct inode_security_struct *isec = inode_security(inode); + struct cred_security_struct *crsec = selinux_cred(new); + u32 sid = current_sid(); + int ret; + + ret = avc_has_perm(sid, isec->sid, + SECCLASS_KERNEL_SERVICE, + KERNEL_SERVICE__CREATE_FILES_AS, + NULL); + + if (ret == 0) + crsec->create_sid = isec->sid; + return ret; +} + +static int selinux_kernel_module_request(char *kmod_name) +{ + struct common_audit_data ad; + + ad.type = LSM_AUDIT_DATA_KMOD; + ad.u.kmod_name = kmod_name; + + return avc_has_perm(current_sid(), SECINITSID_KERNEL, SECCLASS_SYSTEM, + SYSTEM__MODULE_REQUEST, &ad); +} + +static int selinux_kernel_load_from_file(struct file *file, u32 requested) +{ + struct common_audit_data ad; + struct inode_security_struct *isec; + struct file_security_struct *fsec; + u32 sid = current_sid(); + int rc; + + if (file == NULL) + return avc_has_perm(sid, sid, SECCLASS_SYSTEM, requested, NULL); + + ad.type = LSM_AUDIT_DATA_FILE; + ad.u.file = file; + + fsec = selinux_file(file); + if (sid != fsec->sid) { + rc = avc_has_perm(sid, fsec->sid, SECCLASS_FD, FD__USE, &ad); + if (rc) + return rc; + } + + isec = inode_security(file_inode(file)); + return avc_has_perm(sid, isec->sid, SECCLASS_SYSTEM, requested, &ad); +} + +static int selinux_kernel_read_file(struct file *file, + enum kernel_read_file_id id, + bool contents) +{ + int rc = 0; + + BUILD_BUG_ON_MSG(READING_MAX_ID > 8, + "New kernel_read_file_id introduced; update SELinux!"); + + switch (id) { + case READING_FIRMWARE: + rc = selinux_kernel_load_from_file(file, SYSTEM__FIRMWARE_LOAD); + break; + case READING_MODULE: + case READING_MODULE_COMPRESSED: + rc = selinux_kernel_load_from_file(file, SYSTEM__MODULE_LOAD); + break; + case READING_KEXEC_IMAGE: + rc = selinux_kernel_load_from_file(file, + SYSTEM__KEXEC_IMAGE_LOAD); + break; + case READING_KEXEC_INITRAMFS: + rc = selinux_kernel_load_from_file(file, + SYSTEM__KEXEC_INITRAMFS_LOAD); + break; + case READING_POLICY: + rc = selinux_kernel_load_from_file(file, SYSTEM__POLICY_LOAD); + break; + case READING_X509_CERTIFICATE: + rc = selinux_kernel_load_from_file(file, + SYSTEM__X509_CERTIFICATE_LOAD); + break; + default: + break; + } + + return rc; +} + +static int selinux_kernel_load_data(enum kernel_load_data_id id, bool contents) +{ + int rc = 0; + + BUILD_BUG_ON_MSG(LOADING_MAX_ID > 8, + "New kernel_load_data_id introduced; update SELinux!"); + + switch (id) { + case LOADING_FIRMWARE: + rc = selinux_kernel_load_from_file(NULL, SYSTEM__FIRMWARE_LOAD); + break; + case LOADING_MODULE: + rc = selinux_kernel_load_from_file(NULL, SYSTEM__MODULE_LOAD); + break; + case LOADING_KEXEC_IMAGE: + rc = selinux_kernel_load_from_file(NULL, + SYSTEM__KEXEC_IMAGE_LOAD); + break; + case LOADING_KEXEC_INITRAMFS: + rc = selinux_kernel_load_from_file(NULL, + SYSTEM__KEXEC_INITRAMFS_LOAD); + break; + case LOADING_POLICY: + rc = selinux_kernel_load_from_file(NULL, + SYSTEM__POLICY_LOAD); + break; + case LOADING_X509_CERTIFICATE: + rc = selinux_kernel_load_from_file(NULL, + SYSTEM__X509_CERTIFICATE_LOAD); + break; + default: + break; + } + + return rc; +} + +static int selinux_task_setpgid(struct task_struct *p, pid_t pgid) +{ + return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS, + PROCESS__SETPGID, NULL); +} + +static int selinux_task_getpgid(struct task_struct *p) +{ + return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS, + PROCESS__GETPGID, NULL); +} + +static int selinux_task_getsid(struct task_struct *p) +{ + return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS, + PROCESS__GETSESSION, NULL); +} + +static void selinux_current_getlsmprop_subj(struct lsm_prop *prop) +{ + prop->selinux.secid = current_sid(); +} + +static void selinux_task_getlsmprop_obj(struct task_struct *p, + struct lsm_prop *prop) +{ + prop->selinux.secid = task_sid_obj(p); +} + +static int selinux_task_setnice(struct task_struct *p, int nice) +{ + return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS, + PROCESS__SETSCHED, NULL); +} + +static int selinux_task_setioprio(struct task_struct *p, int ioprio) +{ + return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS, + PROCESS__SETSCHED, NULL); +} + +static int selinux_task_getioprio(struct task_struct *p) +{ + return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS, + PROCESS__GETSCHED, NULL); +} + +static int selinux_task_prlimit(const struct cred *cred, const struct cred *tcred, + unsigned int flags) +{ + u32 av = 0; + + if (!flags) + return 0; + if (flags & LSM_PRLIMIT_WRITE) + av |= PROCESS__SETRLIMIT; + if (flags & LSM_PRLIMIT_READ) + av |= PROCESS__GETRLIMIT; + return avc_has_perm(cred_sid(cred), cred_sid(tcred), + SECCLASS_PROCESS, av, NULL); +} + +static int selinux_task_setrlimit(struct task_struct *p, unsigned int resource, + struct rlimit *new_rlim) +{ + struct rlimit *old_rlim = p->signal->rlim + resource; + + /* Control the ability to change the hard limit (whether + lowering or raising it), so that the hard limit can + later be used as a safe reset point for the soft limit + upon context transitions. See selinux_bprm_committing_creds. */ + if (old_rlim->rlim_max != new_rlim->rlim_max) + return avc_has_perm(current_sid(), task_sid_obj(p), + SECCLASS_PROCESS, PROCESS__SETRLIMIT, NULL); + + return 0; +} + +static int selinux_task_setscheduler(struct task_struct *p) +{ + return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS, + PROCESS__SETSCHED, NULL); +} + +static int selinux_task_getscheduler(struct task_struct *p) +{ + return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS, + PROCESS__GETSCHED, NULL); +} + +static int selinux_task_movememory(struct task_struct *p) +{ + return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS, + PROCESS__SETSCHED, NULL); +} + +static int selinux_task_kill(struct task_struct *p, struct kernel_siginfo *info, + int sig, const struct cred *cred) +{ + u32 secid; + u32 perm; + + if (!sig) + perm = PROCESS__SIGNULL; /* null signal; existence test */ + else + perm = signal_to_av(sig); + if (!cred) + secid = current_sid(); + else + secid = cred_sid(cred); + return avc_has_perm(secid, task_sid_obj(p), SECCLASS_PROCESS, perm, NULL); +} + +static void selinux_task_to_inode(struct task_struct *p, + struct inode *inode) +{ + struct inode_security_struct *isec = selinux_inode(inode); + u32 sid = task_sid_obj(p); + + spin_lock(&isec->lock); + isec->sclass = inode_mode_to_security_class(inode->i_mode); + isec->sid = sid; + isec->initialized = LABEL_INITIALIZED; + spin_unlock(&isec->lock); +} + +static int selinux_userns_create(const struct cred *cred) +{ + u32 sid = current_sid(); + + return avc_has_perm(sid, sid, SECCLASS_USER_NAMESPACE, + USER_NAMESPACE__CREATE, NULL); +} + +/* Returns error only if unable to parse addresses */ +static int selinux_parse_skb_ipv4(struct sk_buff *skb, + struct common_audit_data *ad, u8 *proto) +{ + int offset, ihlen, ret = -EINVAL; + struct iphdr _iph, *ih; + + offset = skb_network_offset(skb); + ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph); + if (ih == NULL) + goto out; + + ihlen = ih->ihl * 4; + if (ihlen < sizeof(_iph)) + goto out; + + ad->u.net->v4info.saddr = ih->saddr; + ad->u.net->v4info.daddr = ih->daddr; + ret = 0; + + if (proto) + *proto = ih->protocol; + + switch (ih->protocol) { + case IPPROTO_TCP: { + struct tcphdr _tcph, *th; + + if (ntohs(ih->frag_off) & IP_OFFSET) + break; + + offset += ihlen; + th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph); + if (th == NULL) + break; + + ad->u.net->sport = th->source; + ad->u.net->dport = th->dest; + break; + } + + case IPPROTO_UDP: { + struct udphdr _udph, *uh; + + if (ntohs(ih->frag_off) & IP_OFFSET) + break; + + offset += ihlen; + uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph); + if (uh == NULL) + break; + + ad->u.net->sport = uh->source; + ad->u.net->dport = uh->dest; + break; + } + +#if IS_ENABLED(CONFIG_IP_SCTP) + case IPPROTO_SCTP: { + struct sctphdr _sctph, *sh; + + if (ntohs(ih->frag_off) & IP_OFFSET) + break; + + offset += ihlen; + sh = skb_header_pointer(skb, offset, sizeof(_sctph), &_sctph); + if (sh == NULL) + break; + + ad->u.net->sport = sh->source; + ad->u.net->dport = sh->dest; + break; + } +#endif + default: + break; + } +out: + return ret; +} + +#if IS_ENABLED(CONFIG_IPV6) + +/* Returns error only if unable to parse addresses */ +static int selinux_parse_skb_ipv6(struct sk_buff *skb, + struct common_audit_data *ad, u8 *proto) +{ + u8 nexthdr; + int ret = -EINVAL, offset; + struct ipv6hdr _ipv6h, *ip6; + __be16 frag_off; + + offset = skb_network_offset(skb); + ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h); + if (ip6 == NULL) + goto out; + + ad->u.net->v6info.saddr = ip6->saddr; + ad->u.net->v6info.daddr = ip6->daddr; + ret = 0; + + nexthdr = ip6->nexthdr; + offset += sizeof(_ipv6h); + offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off); + if (offset < 0) + goto out; + + if (proto) + *proto = nexthdr; + + switch (nexthdr) { + case IPPROTO_TCP: { + struct tcphdr _tcph, *th; + + th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph); + if (th == NULL) + break; + + ad->u.net->sport = th->source; + ad->u.net->dport = th->dest; + break; + } + + case IPPROTO_UDP: { + struct udphdr _udph, *uh; + + uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph); + if (uh == NULL) + break; + + ad->u.net->sport = uh->source; + ad->u.net->dport = uh->dest; + break; + } + +#if IS_ENABLED(CONFIG_IP_SCTP) + case IPPROTO_SCTP: { + struct sctphdr _sctph, *sh; + + sh = skb_header_pointer(skb, offset, sizeof(_sctph), &_sctph); + if (sh == NULL) + break; + + ad->u.net->sport = sh->source; + ad->u.net->dport = sh->dest; + break; + } +#endif + /* includes fragments */ + default: + break; + } +out: + return ret; +} + +#endif /* IPV6 */ + +static int selinux_parse_skb(struct sk_buff *skb, struct common_audit_data *ad, + char **_addrp, int src, u8 *proto) +{ + char *addrp; + int ret; + + switch (ad->u.net->family) { + case PF_INET: + ret = selinux_parse_skb_ipv4(skb, ad, proto); + if (ret) + goto parse_error; + addrp = (char *)(src ? &ad->u.net->v4info.saddr : + &ad->u.net->v4info.daddr); + goto okay; + +#if IS_ENABLED(CONFIG_IPV6) + case PF_INET6: + ret = selinux_parse_skb_ipv6(skb, ad, proto); + if (ret) + goto parse_error; + addrp = (char *)(src ? &ad->u.net->v6info.saddr : + &ad->u.net->v6info.daddr); + goto okay; +#endif /* IPV6 */ + default: + addrp = NULL; + goto okay; + } + +parse_error: + pr_warn( + "SELinux: failure in selinux_parse_skb()," + " unable to parse packet\n"); + return ret; + +okay: + if (_addrp) + *_addrp = addrp; + return 0; +} + +/** + * selinux_skb_peerlbl_sid - Determine the peer label of a packet + * @skb: the packet + * @family: protocol family + * @sid: the packet's peer label SID + * + * Description: + * Check the various different forms of network peer labeling and determine + * the peer label/SID for the packet; most of the magic actually occurs in + * the security server function security_net_peersid_cmp(). The function + * returns zero if the value in @sid is valid (although it may be SECSID_NULL) + * or -EACCES if @sid is invalid due to inconsistencies with the different + * peer labels. + * + */ +static int selinux_skb_peerlbl_sid(struct sk_buff *skb, u16 family, u32 *sid) +{ + int err; + u32 xfrm_sid; + u32 nlbl_sid; + u32 nlbl_type; + + err = selinux_xfrm_skb_sid(skb, &xfrm_sid); + if (unlikely(err)) + return -EACCES; + err = selinux_netlbl_skbuff_getsid(skb, family, &nlbl_type, &nlbl_sid); + if (unlikely(err)) + return -EACCES; + + err = security_net_peersid_resolve(nlbl_sid, + nlbl_type, xfrm_sid, sid); + if (unlikely(err)) { + pr_warn( + "SELinux: failure in selinux_skb_peerlbl_sid()," + " unable to determine packet's peer label\n"); + return -EACCES; + } + + return 0; +} + +/** + * selinux_conn_sid - Determine the child socket label for a connection + * @sk_sid: the parent socket's SID + * @skb_sid: the packet's SID + * @conn_sid: the resulting connection SID + * + * If @skb_sid is valid then the user:role:type information from @sk_sid is + * combined with the MLS information from @skb_sid in order to create + * @conn_sid. If @skb_sid is not valid then @conn_sid is simply a copy + * of @sk_sid. Returns zero on success, negative values on failure. + * + */ +static int selinux_conn_sid(u32 sk_sid, u32 skb_sid, u32 *conn_sid) +{ + int err = 0; + + if (skb_sid != SECSID_NULL) + err = security_sid_mls_copy(sk_sid, skb_sid, + conn_sid); + else + *conn_sid = sk_sid; + + return err; +} + +/* socket security operations */ + +static int socket_sockcreate_sid(const struct cred_security_struct *crsec, + u16 secclass, u32 *socksid) +{ + if (crsec->sockcreate_sid > SECSID_NULL) { + *socksid = crsec->sockcreate_sid; + return 0; + } + + return security_transition_sid(crsec->sid, crsec->sid, + secclass, NULL, socksid); +} + +static bool sock_skip_has_perm(u32 sid) +{ + if (sid == SECINITSID_KERNEL) + return true; + + /* + * Before POLICYDB_CAP_USERSPACE_INITIAL_CONTEXT, sockets that + * inherited the kernel context from early boot used to be skipped + * here, so preserve that behavior unless the capability is set. + * + * By setting the capability the policy signals that it is ready + * for this quirk to be fixed. Note that sockets created by a kernel + * thread or a usermode helper executed without a transition will + * still be skipped in this check regardless of the policycap + * setting. + */ + if (!selinux_policycap_userspace_initial_context() && + sid == SECINITSID_INIT) + return true; + return false; +} + + +static int sock_has_perm(struct sock *sk, u32 perms) +{ + struct sk_security_struct *sksec = selinux_sock(sk); + struct common_audit_data ad; + struct lsm_network_audit net; + + if (sock_skip_has_perm(sksec->sid)) + return 0; + + ad_net_init_from_sk(&ad, &net, sk); + + return avc_has_perm(current_sid(), sksec->sid, sksec->sclass, perms, + &ad); +} + +static int selinux_socket_create(int family, int type, + int protocol, int kern) +{ + const struct cred_security_struct *crsec = selinux_cred(current_cred()); + u32 newsid; + u16 secclass; + int rc; + + if (kern) + return 0; + + secclass = socket_type_to_security_class(family, type, protocol); + rc = socket_sockcreate_sid(crsec, secclass, &newsid); + if (rc) + return rc; + + return avc_has_perm(crsec->sid, newsid, secclass, SOCKET__CREATE, NULL); +} + +static int selinux_socket_post_create(struct socket *sock, int family, + int type, int protocol, int kern) +{ + const struct cred_security_struct *crsec = selinux_cred(current_cred()); + struct inode_security_struct *isec = inode_security_novalidate(SOCK_INODE(sock)); + struct sk_security_struct *sksec; + u16 sclass = socket_type_to_security_class(family, type, protocol); + u32 sid = SECINITSID_KERNEL; + int err = 0; + + if (!kern) { + err = socket_sockcreate_sid(crsec, sclass, &sid); + if (err) + return err; + } + + isec->sclass = sclass; + isec->sid = sid; + isec->initialized = LABEL_INITIALIZED; + + if (sock->sk) { + sksec = selinux_sock(sock->sk); + sksec->sclass = sclass; + sksec->sid = sid; + /* Allows detection of the first association on this socket */ + if (sksec->sclass == SECCLASS_SCTP_SOCKET) + sksec->sctp_assoc_state = SCTP_ASSOC_UNSET; + + err = selinux_netlbl_socket_post_create(sock->sk, family); + } + + return err; +} + +static int selinux_socket_socketpair(struct socket *socka, + struct socket *sockb) +{ + struct sk_security_struct *sksec_a = selinux_sock(socka->sk); + struct sk_security_struct *sksec_b = selinux_sock(sockb->sk); + + sksec_a->peer_sid = sksec_b->sid; + sksec_b->peer_sid = sksec_a->sid; + + return 0; +} + +/* Range of port numbers used to automatically bind. + Need to determine whether we should perform a name_bind + permission check between the socket and the port number. */ + +static int __selinux_socket_bind(struct sock *sk, struct sockaddr *address, int addrlen) +{ + struct sk_security_struct *sksec = selinux_sock(sk); + u16 family; + int err; + + err = sock_has_perm(sk, SOCKET__BIND); + if (err) + goto out; + + /* If PF_INET or PF_INET6, check name_bind permission for the port. */ + family = sk->sk_family; + if (family == PF_INET || family == PF_INET6) { + char *addrp; + struct common_audit_data ad; + struct lsm_network_audit net = {0,}; + struct sockaddr_in *addr4 = NULL; + struct sockaddr_in6 *addr6 = NULL; + u16 family_sa; + unsigned short snum; + u32 sid, node_perm; + + /* + * sctp_bindx(3) calls via selinux_sctp_bind_connect() + * that validates multiple binding addresses. Because of this + * need to check address->sa_family as it is possible to have + * sk->sk_family = PF_INET6 with addr->sa_family = AF_INET. + */ + if (addrlen < offsetofend(struct sockaddr, sa_family)) + return -EINVAL; + family_sa = address->sa_family; + switch (family_sa) { + case AF_UNSPEC: + case AF_INET: + if (addrlen < sizeof(struct sockaddr_in)) + return -EINVAL; + addr4 = (struct sockaddr_in *)address; + if (family_sa == AF_UNSPEC) { + if (family == PF_INET6) { + /* Length check from inet6_bind_sk() */ + if (addrlen < SIN6_LEN_RFC2133) + return -EINVAL; + /* Family check from __inet6_bind() */ + goto err_af; + } + /* see __inet_bind(), we only want to allow + * AF_UNSPEC if the address is INADDR_ANY + */ + if (addr4->sin_addr.s_addr != htonl(INADDR_ANY)) + goto err_af; + family_sa = AF_INET; + } + snum = ntohs(addr4->sin_port); + addrp = (char *)&addr4->sin_addr.s_addr; + break; + case AF_INET6: + if (addrlen < SIN6_LEN_RFC2133) + return -EINVAL; + addr6 = (struct sockaddr_in6 *)address; + snum = ntohs(addr6->sin6_port); + addrp = (char *)&addr6->sin6_addr.s6_addr; + break; + default: + goto err_af; + } + + ad.type = LSM_AUDIT_DATA_NET; + ad.u.net = &net; + ad.u.net->sport = htons(snum); + ad.u.net->family = family_sa; + + if (snum) { + int low, high; + + inet_get_local_port_range(sock_net(sk), &low, &high); + + if (inet_port_requires_bind_service(sock_net(sk), snum) || + snum < low || snum > high) { + err = sel_netport_sid(sk->sk_protocol, + snum, &sid); + if (err) + goto out; + err = avc_has_perm(sksec->sid, sid, + sksec->sclass, + SOCKET__NAME_BIND, &ad); + if (err) + goto out; + } + } + + switch (sksec->sclass) { + case SECCLASS_TCP_SOCKET: + node_perm = TCP_SOCKET__NODE_BIND; + break; + + case SECCLASS_UDP_SOCKET: + node_perm = UDP_SOCKET__NODE_BIND; + break; + + case SECCLASS_SCTP_SOCKET: + node_perm = SCTP_SOCKET__NODE_BIND; + break; + + default: + node_perm = RAWIP_SOCKET__NODE_BIND; + break; + } + + err = sel_netnode_sid(addrp, family_sa, &sid); + if (err) + goto out; + + if (family_sa == AF_INET) + ad.u.net->v4info.saddr = addr4->sin_addr.s_addr; + else + ad.u.net->v6info.saddr = addr6->sin6_addr; + + err = avc_has_perm(sksec->sid, sid, + sksec->sclass, node_perm, &ad); + if (err) + goto out; + } +out: + return err; +err_af: + /* Note that SCTP services expect -EINVAL, others -EAFNOSUPPORT. */ + if (sk->sk_protocol == IPPROTO_SCTP) + return -EINVAL; + return -EAFNOSUPPORT; +} + +static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, int addrlen) +{ + return __selinux_socket_bind(sock->sk, address, addrlen); +} + +/* This supports connect(2) and SCTP connect services such as sctp_connectx(3) + * and sctp_sendmsg(3) as described in Documentation/security/SCTP.rst + */ +static int selinux_socket_connect_helper(struct sock *sk, + struct sockaddr *address, int addrlen) +{ + struct sk_security_struct *sksec = selinux_sock(sk); + int err; + + err = sock_has_perm(sk, SOCKET__CONNECT); + if (err) + return err; + if (addrlen < offsetofend(struct sockaddr, sa_family)) + return -EINVAL; + + /* connect(AF_UNSPEC) has special handling, as it is a documented + * way to disconnect the socket + */ + if (address->sa_family == AF_UNSPEC) + return 0; + + /* + * If a TCP or SCTP socket, check name_connect permission + * for the port. + */ + if (sksec->sclass == SECCLASS_TCP_SOCKET || + sksec->sclass == SECCLASS_SCTP_SOCKET) { + struct common_audit_data ad; + struct lsm_network_audit net = {0,}; + struct sockaddr_in *addr4 = NULL; + struct sockaddr_in6 *addr6 = NULL; + unsigned short snum; + u32 sid, perm; + + /* sctp_connectx(3) calls via selinux_sctp_bind_connect() + * that validates multiple connect addresses. Because of this + * need to check address->sa_family as it is possible to have + * sk->sk_family = PF_INET6 with addr->sa_family = AF_INET. + */ + switch (address->sa_family) { + case AF_INET: + addr4 = (struct sockaddr_in *)address; + if (addrlen < sizeof(struct sockaddr_in)) + return -EINVAL; + snum = ntohs(addr4->sin_port); + break; + case AF_INET6: + addr6 = (struct sockaddr_in6 *)address; + if (addrlen < SIN6_LEN_RFC2133) + return -EINVAL; + snum = ntohs(addr6->sin6_port); + break; + default: + /* Note that SCTP services expect -EINVAL, whereas + * others expect -EAFNOSUPPORT. + */ + if (sksec->sclass == SECCLASS_SCTP_SOCKET) + return -EINVAL; + else + return -EAFNOSUPPORT; + } + + err = sel_netport_sid(sk->sk_protocol, snum, &sid); + if (err) + return err; + + switch (sksec->sclass) { + case SECCLASS_TCP_SOCKET: + perm = TCP_SOCKET__NAME_CONNECT; + break; + case SECCLASS_SCTP_SOCKET: + perm = SCTP_SOCKET__NAME_CONNECT; + break; + } + + ad.type = LSM_AUDIT_DATA_NET; + ad.u.net = &net; + ad.u.net->dport = htons(snum); + ad.u.net->family = address->sa_family; + err = avc_has_perm(sksec->sid, sid, sksec->sclass, perm, &ad); + if (err) + return err; + } + + return 0; +} + +/* Supports connect(2), see comments in selinux_socket_connect_helper() */ +static int selinux_socket_connect(struct socket *sock, + struct sockaddr *address, int addrlen) +{ + int err; + struct sock *sk = sock->sk; + + err = selinux_socket_connect_helper(sk, address, addrlen); + if (err) + return err; + + return selinux_netlbl_socket_connect(sk, address); +} + +static int selinux_socket_listen(struct socket *sock, int backlog) +{ + return sock_has_perm(sock->sk, SOCKET__LISTEN); +} + +static int selinux_socket_accept(struct socket *sock, struct socket *newsock) +{ + int err; + struct inode_security_struct *isec; + struct inode_security_struct *newisec; + u16 sclass; + u32 sid; + + err = sock_has_perm(sock->sk, SOCKET__ACCEPT); + if (err) + return err; + + isec = inode_security_novalidate(SOCK_INODE(sock)); + spin_lock(&isec->lock); + sclass = isec->sclass; + sid = isec->sid; + spin_unlock(&isec->lock); + + newisec = inode_security_novalidate(SOCK_INODE(newsock)); + newisec->sclass = sclass; + newisec->sid = sid; + newisec->initialized = LABEL_INITIALIZED; + + return 0; +} + +static int selinux_socket_sendmsg(struct socket *sock, struct msghdr *msg, + int size) +{ + int rc; + struct sockaddr *const addr = msg->msg_name; + const int addrlen = msg->msg_namelen; + + rc = sock_has_perm(sock->sk, SOCKET__WRITE); + if (rc) + return rc; + + if (addr && (msg->msg_flags & MSG_FASTOPEN) && + (sk_is_tcp(sock->sk) || + (sk_is_inet(sock->sk) && sock->sk->sk_type == SOCK_STREAM && + sock->sk->sk_protocol == IPPROTO_MPTCP))) { + rc = selinux_socket_connect(sock, addr, addrlen); + if (rc) + return rc; + } + + return 0; +} + +static int selinux_socket_recvmsg(struct socket *sock, struct msghdr *msg, + int size, int flags) +{ + return sock_has_perm(sock->sk, SOCKET__READ); +} + +static int selinux_socket_getsockname(struct socket *sock) +{ + return sock_has_perm(sock->sk, SOCKET__GETATTR); +} + +static int selinux_socket_getpeername(struct socket *sock) +{ + return sock_has_perm(sock->sk, SOCKET__GETATTR); +} + +static int selinux_socket_setsockopt(struct socket *sock, int level, int optname) +{ + int err; + + err = sock_has_perm(sock->sk, SOCKET__SETOPT); + if (err) + return err; + + return selinux_netlbl_socket_setsockopt(sock, level, optname); +} + +static int selinux_socket_getsockopt(struct socket *sock, int level, + int optname) +{ + return sock_has_perm(sock->sk, SOCKET__GETOPT); +} + +static int selinux_socket_shutdown(struct socket *sock, int how) +{ + return sock_has_perm(sock->sk, SOCKET__SHUTDOWN); +} + +static int selinux_socket_unix_stream_connect(struct sock *sock, + struct sock *other, + struct sock *newsk) +{ + struct sk_security_struct *sksec_sock = selinux_sock(sock); + struct sk_security_struct *sksec_other = selinux_sock(other); + struct sk_security_struct *sksec_new = selinux_sock(newsk); + struct common_audit_data ad; + struct lsm_network_audit net; + int err; + + ad_net_init_from_sk(&ad, &net, other); + + err = avc_has_perm(sksec_sock->sid, sksec_other->sid, + sksec_other->sclass, + UNIX_STREAM_SOCKET__CONNECTTO, &ad); + if (err) + return err; + + /* server child socket */ + sksec_new->peer_sid = sksec_sock->sid; + err = security_sid_mls_copy(sksec_other->sid, + sksec_sock->sid, &sksec_new->sid); + if (err) + return err; + + /* connecting socket */ + sksec_sock->peer_sid = sksec_new->sid; + + return 0; +} + +static int selinux_socket_unix_may_send(struct socket *sock, + struct socket *other) +{ + struct sk_security_struct *ssec = selinux_sock(sock->sk); + struct sk_security_struct *osec = selinux_sock(other->sk); + struct common_audit_data ad; + struct lsm_network_audit net; + + ad_net_init_from_sk(&ad, &net, other->sk); + + return avc_has_perm(ssec->sid, osec->sid, osec->sclass, SOCKET__SENDTO, + &ad); +} + +static int selinux_inet_sys_rcv_skb(struct net *ns, int ifindex, + char *addrp, u16 family, u32 peer_sid, + struct common_audit_data *ad) +{ + int err; + u32 if_sid; + u32 node_sid; + + err = sel_netif_sid(ns, ifindex, &if_sid); + if (err) + return err; + err = avc_has_perm(peer_sid, if_sid, + SECCLASS_NETIF, NETIF__INGRESS, ad); + if (err) + return err; + + err = sel_netnode_sid(addrp, family, &node_sid); + if (err) + return err; + return avc_has_perm(peer_sid, node_sid, + SECCLASS_NODE, NODE__RECVFROM, ad); +} + +static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb, + u16 family) +{ + int err = 0; + struct sk_security_struct *sksec = selinux_sock(sk); + u32 sk_sid = sksec->sid; + struct common_audit_data ad; + struct lsm_network_audit net; + char *addrp; + + ad_net_init_from_iif(&ad, &net, skb->skb_iif, family); + err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL); + if (err) + return err; + + if (selinux_secmark_enabled()) { + err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET, + PACKET__RECV, &ad); + if (err) + return err; + } + + err = selinux_netlbl_sock_rcv_skb(sksec, skb, family, &ad); + if (err) + return err; + err = selinux_xfrm_sock_rcv_skb(sksec->sid, skb, &ad); + + return err; +} + +static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb) +{ + int err, peerlbl_active, secmark_active; + struct sk_security_struct *sksec = selinux_sock(sk); + u16 family = sk->sk_family; + u32 sk_sid = sksec->sid; + struct common_audit_data ad; + struct lsm_network_audit net; + char *addrp; + + if (family != PF_INET && family != PF_INET6) + return 0; + + /* Handle mapped IPv4 packets arriving via IPv6 sockets */ + if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP)) + family = PF_INET; + + /* If any sort of compatibility mode is enabled then handoff processing + * to the selinux_sock_rcv_skb_compat() function to deal with the + * special handling. We do this in an attempt to keep this function + * as fast and as clean as possible. */ + if (!selinux_policycap_netpeer()) + return selinux_sock_rcv_skb_compat(sk, skb, family); + + secmark_active = selinux_secmark_enabled(); + peerlbl_active = selinux_peerlbl_enabled(); + if (!secmark_active && !peerlbl_active) + return 0; + + ad_net_init_from_iif(&ad, &net, skb->skb_iif, family); + err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL); + if (err) + return err; + + if (peerlbl_active) { + u32 peer_sid; + + err = selinux_skb_peerlbl_sid(skb, family, &peer_sid); + if (err) + return err; + err = selinux_inet_sys_rcv_skb(sock_net(sk), skb->skb_iif, + addrp, family, peer_sid, &ad); + if (err) { + selinux_netlbl_err(skb, family, err, 0); + return err; + } + err = avc_has_perm(sk_sid, peer_sid, SECCLASS_PEER, + PEER__RECV, &ad); + if (err) { + selinux_netlbl_err(skb, family, err, 0); + return err; + } + } + + if (secmark_active) { + err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET, + PACKET__RECV, &ad); + if (err) + return err; + } + + return err; +} + +static int selinux_socket_getpeersec_stream(struct socket *sock, + sockptr_t optval, sockptr_t optlen, + unsigned int len) +{ + int err = 0; + char *scontext = NULL; + u32 scontext_len; + struct sk_security_struct *sksec = selinux_sock(sock->sk); + u32 peer_sid = SECSID_NULL; + + if (sksec->sclass == SECCLASS_UNIX_STREAM_SOCKET || + sksec->sclass == SECCLASS_TCP_SOCKET || + sksec->sclass == SECCLASS_SCTP_SOCKET) + peer_sid = sksec->peer_sid; + if (peer_sid == SECSID_NULL) + return -ENOPROTOOPT; + + err = security_sid_to_context(peer_sid, &scontext, + &scontext_len); + if (err) + return err; + if (scontext_len > len) { + err = -ERANGE; + goto out_len; + } + + if (copy_to_sockptr(optval, scontext, scontext_len)) + err = -EFAULT; +out_len: + if (copy_to_sockptr(optlen, &scontext_len, sizeof(scontext_len))) + err = -EFAULT; + kfree(scontext); + return err; +} + +static int selinux_socket_getpeersec_dgram(struct socket *sock, + struct sk_buff *skb, u32 *secid) +{ + u32 peer_secid = SECSID_NULL; + u16 family; + + if (skb && skb->protocol == htons(ETH_P_IP)) + family = PF_INET; + else if (skb && skb->protocol == htons(ETH_P_IPV6)) + family = PF_INET6; + else if (sock) + family = sock->sk->sk_family; + else { + *secid = SECSID_NULL; + return -EINVAL; + } + + if (sock && family == PF_UNIX) { + struct inode_security_struct *isec; + isec = inode_security_novalidate(SOCK_INODE(sock)); + peer_secid = isec->sid; + } else if (skb) + selinux_skb_peerlbl_sid(skb, family, &peer_secid); + + *secid = peer_secid; + if (peer_secid == SECSID_NULL) + return -ENOPROTOOPT; + return 0; +} + +static int selinux_sk_alloc_security(struct sock *sk, int family, gfp_t priority) +{ + struct sk_security_struct *sksec = selinux_sock(sk); + + sksec->peer_sid = SECINITSID_UNLABELED; + sksec->sid = SECINITSID_UNLABELED; + sksec->sclass = SECCLASS_SOCKET; + selinux_netlbl_sk_security_reset(sksec); + + return 0; +} + +static void selinux_sk_free_security(struct sock *sk) +{ + struct sk_security_struct *sksec = selinux_sock(sk); + + selinux_netlbl_sk_security_free(sksec); +} + +static void selinux_sk_clone_security(const struct sock *sk, struct sock *newsk) +{ + struct sk_security_struct *sksec = selinux_sock(sk); + struct sk_security_struct *newsksec = selinux_sock(newsk); + + newsksec->sid = sksec->sid; + newsksec->peer_sid = sksec->peer_sid; + newsksec->sclass = sksec->sclass; + + selinux_netlbl_sk_security_reset(newsksec); +} + +static void selinux_sk_getsecid(const struct sock *sk, u32 *secid) +{ + if (!sk) + *secid = SECINITSID_ANY_SOCKET; + else { + const struct sk_security_struct *sksec = selinux_sock(sk); + + *secid = sksec->sid; + } +} + +static void selinux_sock_graft(struct sock *sk, struct socket *parent) +{ + struct inode_security_struct *isec = + inode_security_novalidate(SOCK_INODE(parent)); + struct sk_security_struct *sksec = selinux_sock(sk); + + if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6 || + sk->sk_family == PF_UNIX) + isec->sid = sksec->sid; + sksec->sclass = isec->sclass; +} + +/* + * Determines peer_secid for the asoc and updates socket's peer label + * if it's the first association on the socket. + */ +static int selinux_sctp_process_new_assoc(struct sctp_association *asoc, + struct sk_buff *skb) +{ + struct sock *sk = asoc->base.sk; + u16 family = sk->sk_family; + struct sk_security_struct *sksec = selinux_sock(sk); + struct common_audit_data ad; + struct lsm_network_audit net; + int err; + + /* handle mapped IPv4 packets arriving via IPv6 sockets */ + if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP)) + family = PF_INET; + + if (selinux_peerlbl_enabled()) { + asoc->peer_secid = SECSID_NULL; + + /* This will return peer_sid = SECSID_NULL if there are + * no peer labels, see security_net_peersid_resolve(). + */ + err = selinux_skb_peerlbl_sid(skb, family, &asoc->peer_secid); + if (err) + return err; + + if (asoc->peer_secid == SECSID_NULL) + asoc->peer_secid = SECINITSID_UNLABELED; + } else { + asoc->peer_secid = SECINITSID_UNLABELED; + } + + if (sksec->sctp_assoc_state == SCTP_ASSOC_UNSET) { + sksec->sctp_assoc_state = SCTP_ASSOC_SET; + + /* Here as first association on socket. As the peer SID + * was allowed by peer recv (and the netif/node checks), + * then it is approved by policy and used as the primary + * peer SID for getpeercon(3). + */ + sksec->peer_sid = asoc->peer_secid; + } else if (sksec->peer_sid != asoc->peer_secid) { + /* Other association peer SIDs are checked to enforce + * consistency among the peer SIDs. + */ + ad_net_init_from_sk(&ad, &net, asoc->base.sk); + err = avc_has_perm(sksec->peer_sid, asoc->peer_secid, + sksec->sclass, SCTP_SOCKET__ASSOCIATION, + &ad); + if (err) + return err; + } + return 0; +} + +/* Called whenever SCTP receives an INIT or COOKIE ECHO chunk. This + * happens on an incoming connect(2), sctp_connectx(3) or + * sctp_sendmsg(3) (with no association already present). + */ +static int selinux_sctp_assoc_request(struct sctp_association *asoc, + struct sk_buff *skb) +{ + struct sk_security_struct *sksec = selinux_sock(asoc->base.sk); + u32 conn_sid; + int err; + + if (!selinux_policycap_extsockclass()) + return 0; + + err = selinux_sctp_process_new_assoc(asoc, skb); + if (err) + return err; + + /* Compute the MLS component for the connection and store + * the information in asoc. This will be used by SCTP TCP type + * sockets and peeled off connections as they cause a new + * socket to be generated. selinux_sctp_sk_clone() will then + * plug this into the new socket. + */ + err = selinux_conn_sid(sksec->sid, asoc->peer_secid, &conn_sid); + if (err) + return err; + + asoc->secid = conn_sid; + + /* Set any NetLabel labels including CIPSO/CALIPSO options. */ + return selinux_netlbl_sctp_assoc_request(asoc, skb); +} + +/* Called when SCTP receives a COOKIE ACK chunk as the final + * response to an association request (initited by us). + */ +static int selinux_sctp_assoc_established(struct sctp_association *asoc, + struct sk_buff *skb) +{ + struct sk_security_struct *sksec = selinux_sock(asoc->base.sk); + + if (!selinux_policycap_extsockclass()) + return 0; + + /* Inherit secid from the parent socket - this will be picked up + * by selinux_sctp_sk_clone() if the association gets peeled off + * into a new socket. + */ + asoc->secid = sksec->sid; + + return selinux_sctp_process_new_assoc(asoc, skb); +} + +/* Check if sctp IPv4/IPv6 addresses are valid for binding or connecting + * based on their @optname. + */ +static int selinux_sctp_bind_connect(struct sock *sk, int optname, + struct sockaddr *address, + int addrlen) +{ + int len, err = 0, walk_size = 0; + void *addr_buf; + struct sockaddr *addr; + + if (!selinux_policycap_extsockclass()) + return 0; + + /* Process one or more addresses that may be IPv4 or IPv6 */ + addr_buf = address; + + while (walk_size < addrlen) { + if (walk_size + sizeof(sa_family_t) > addrlen) + return -EINVAL; + + addr = addr_buf; + switch (addr->sa_family) { + case AF_UNSPEC: + case AF_INET: + len = sizeof(struct sockaddr_in); + break; + case AF_INET6: + len = sizeof(struct sockaddr_in6); + break; + default: + return -EINVAL; + } + + if (walk_size + len > addrlen) + return -EINVAL; + + err = -EINVAL; + switch (optname) { + /* Bind checks */ + case SCTP_PRIMARY_ADDR: + case SCTP_SET_PEER_PRIMARY_ADDR: + case SCTP_SOCKOPT_BINDX_ADD: + err = __selinux_socket_bind(sk, addr, len); + break; + /* Connect checks */ + case SCTP_SOCKOPT_CONNECTX: + case SCTP_PARAM_SET_PRIMARY: + case SCTP_PARAM_ADD_IP: + case SCTP_SENDMSG_CONNECT: + err = selinux_socket_connect_helper(sk, addr, len); + if (err) + return err; + + /* As selinux_sctp_bind_connect() is called by the + * SCTP protocol layer, the socket is already locked, + * therefore selinux_netlbl_socket_connect_locked() + * is called here. The situations handled are: + * sctp_connectx(3), sctp_sendmsg(3), sendmsg(2), + * whenever a new IP address is added or when a new + * primary address is selected. + * Note that an SCTP connect(2) call happens before + * the SCTP protocol layer and is handled via + * selinux_socket_connect(). + */ + err = selinux_netlbl_socket_connect_locked(sk, addr); + break; + } + + if (err) + return err; + + addr_buf += len; + walk_size += len; + } + + return 0; +} + +/* Called whenever a new socket is created by accept(2) or sctp_peeloff(3). */ +static void selinux_sctp_sk_clone(struct sctp_association *asoc, struct sock *sk, + struct sock *newsk) +{ + struct sk_security_struct *sksec = selinux_sock(sk); + struct sk_security_struct *newsksec = selinux_sock(newsk); + + /* If policy does not support SECCLASS_SCTP_SOCKET then call + * the non-sctp clone version. + */ + if (!selinux_policycap_extsockclass()) + return selinux_sk_clone_security(sk, newsk); + + newsksec->sid = asoc->secid; + newsksec->peer_sid = asoc->peer_secid; + newsksec->sclass = sksec->sclass; + selinux_netlbl_sctp_sk_clone(sk, newsk); +} + +static int selinux_mptcp_add_subflow(struct sock *sk, struct sock *ssk) +{ + struct sk_security_struct *ssksec = selinux_sock(ssk); + struct sk_security_struct *sksec = selinux_sock(sk); + + ssksec->sclass = sksec->sclass; + ssksec->sid = sksec->sid; + + /* replace the existing subflow label deleting the existing one + * and re-recreating a new label using the updated context + */ + selinux_netlbl_sk_security_free(ssksec); + return selinux_netlbl_socket_post_create(ssk, ssk->sk_family); +} + +static int selinux_inet_conn_request(const struct sock *sk, struct sk_buff *skb, + struct request_sock *req) +{ + struct sk_security_struct *sksec = selinux_sock(sk); + int err; + u16 family = req->rsk_ops->family; + u32 connsid; + u32 peersid; + + err = selinux_skb_peerlbl_sid(skb, family, &peersid); + if (err) + return err; + err = selinux_conn_sid(sksec->sid, peersid, &connsid); + if (err) + return err; + req->secid = connsid; + req->peer_secid = peersid; + + return selinux_netlbl_inet_conn_request(req, family); +} + +static void selinux_inet_csk_clone(struct sock *newsk, + const struct request_sock *req) +{ + struct sk_security_struct *newsksec = selinux_sock(newsk); + + newsksec->sid = req->secid; + newsksec->peer_sid = req->peer_secid; + /* NOTE: Ideally, we should also get the isec->sid for the + new socket in sync, but we don't have the isec available yet. + So we will wait until sock_graft to do it, by which + time it will have been created and available. */ + + /* We don't need to take any sort of lock here as we are the only + * thread with access to newsksec */ + selinux_netlbl_inet_csk_clone(newsk, req->rsk_ops->family); +} + +static void selinux_inet_conn_established(struct sock *sk, struct sk_buff *skb) +{ + u16 family = sk->sk_family; + struct sk_security_struct *sksec = selinux_sock(sk); + + /* handle mapped IPv4 packets arriving via IPv6 sockets */ + if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP)) + family = PF_INET; + + selinux_skb_peerlbl_sid(skb, family, &sksec->peer_sid); +} + +static int selinux_secmark_relabel_packet(u32 sid) +{ + return avc_has_perm(current_sid(), sid, SECCLASS_PACKET, PACKET__RELABELTO, + NULL); +} + +static void selinux_secmark_refcount_inc(void) +{ + atomic_inc(&selinux_secmark_refcount); +} + +static void selinux_secmark_refcount_dec(void) +{ + atomic_dec(&selinux_secmark_refcount); +} + +static void selinux_req_classify_flow(const struct request_sock *req, + struct flowi_common *flic) +{ + flic->flowic_secid = req->secid; +} + +static int selinux_tun_dev_alloc_security(void *security) +{ + struct tun_security_struct *tunsec = selinux_tun_dev(security); + + tunsec->sid = current_sid(); + return 0; +} + +static int selinux_tun_dev_create(void) +{ + u32 sid = current_sid(); + + /* we aren't taking into account the "sockcreate" SID since the socket + * that is being created here is not a socket in the traditional sense, + * instead it is a private sock, accessible only to the kernel, and + * representing a wide range of network traffic spanning multiple + * connections unlike traditional sockets - check the TUN driver to + * get a better understanding of why this socket is special */ + + return avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET, TUN_SOCKET__CREATE, + NULL); +} + +static int selinux_tun_dev_attach_queue(void *security) +{ + struct tun_security_struct *tunsec = selinux_tun_dev(security); + + return avc_has_perm(current_sid(), tunsec->sid, SECCLASS_TUN_SOCKET, + TUN_SOCKET__ATTACH_QUEUE, NULL); +} + +static int selinux_tun_dev_attach(struct sock *sk, void *security) +{ + struct tun_security_struct *tunsec = selinux_tun_dev(security); + struct sk_security_struct *sksec = selinux_sock(sk); + + /* we don't currently perform any NetLabel based labeling here and it + * isn't clear that we would want to do so anyway; while we could apply + * labeling without the support of the TUN user the resulting labeled + * traffic from the other end of the connection would almost certainly + * cause confusion to the TUN user that had no idea network labeling + * protocols were being used */ + + sksec->sid = tunsec->sid; + sksec->sclass = SECCLASS_TUN_SOCKET; + + return 0; +} + +static int selinux_tun_dev_open(void *security) +{ + struct tun_security_struct *tunsec = selinux_tun_dev(security); + u32 sid = current_sid(); + int err; + + err = avc_has_perm(sid, tunsec->sid, SECCLASS_TUN_SOCKET, + TUN_SOCKET__RELABELFROM, NULL); + if (err) + return err; + err = avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET, + TUN_SOCKET__RELABELTO, NULL); + if (err) + return err; + tunsec->sid = sid; + + return 0; +} + +#ifdef CONFIG_NETFILTER + +static unsigned int selinux_ip_forward(void *priv, struct sk_buff *skb, + const struct nf_hook_state *state) +{ + int ifindex; + u16 family; + char *addrp; + u32 peer_sid; + struct common_audit_data ad; + struct lsm_network_audit net; + int secmark_active, peerlbl_active; + + if (!selinux_policycap_netpeer()) + return NF_ACCEPT; + + secmark_active = selinux_secmark_enabled(); + peerlbl_active = selinux_peerlbl_enabled(); + if (!secmark_active && !peerlbl_active) + return NF_ACCEPT; + + family = state->pf; + if (selinux_skb_peerlbl_sid(skb, family, &peer_sid) != 0) + return NF_DROP; + + ifindex = state->in->ifindex; + ad_net_init_from_iif(&ad, &net, ifindex, family); + if (selinux_parse_skb(skb, &ad, &addrp, 1, NULL) != 0) + return NF_DROP; + + if (peerlbl_active) { + int err; + + err = selinux_inet_sys_rcv_skb(state->net, ifindex, + addrp, family, peer_sid, &ad); + if (err) { + selinux_netlbl_err(skb, family, err, 1); + return NF_DROP; + } + } + + if (secmark_active) + if (avc_has_perm(peer_sid, skb->secmark, + SECCLASS_PACKET, PACKET__FORWARD_IN, &ad)) + return NF_DROP; + + if (netlbl_enabled()) + /* we do this in the FORWARD path and not the POST_ROUTING + * path because we want to make sure we apply the necessary + * labeling before IPsec is applied so we can leverage AH + * protection */ + if (selinux_netlbl_skbuff_setsid(skb, family, peer_sid) != 0) + return NF_DROP; + + return NF_ACCEPT; +} + +static unsigned int selinux_ip_output(void *priv, struct sk_buff *skb, + const struct nf_hook_state *state) +{ + struct sock *sk; + u32 sid; + + if (!netlbl_enabled()) + return NF_ACCEPT; + + /* we do this in the LOCAL_OUT path and not the POST_ROUTING path + * because we want to make sure we apply the necessary labeling + * before IPsec is applied so we can leverage AH protection */ + sk = skb_to_full_sk(skb); + if (sk) { + struct sk_security_struct *sksec; + + if (sk_listener(sk)) + /* if the socket is the listening state then this + * packet is a SYN-ACK packet which means it needs to + * be labeled based on the connection/request_sock and + * not the parent socket. unfortunately, we can't + * lookup the request_sock yet as it isn't queued on + * the parent socket until after the SYN-ACK is sent. + * the "solution" is to simply pass the packet as-is + * as any IP option based labeling should be copied + * from the initial connection request (in the IP + * layer). it is far from ideal, but until we get a + * security label in the packet itself this is the + * best we can do. */ + return NF_ACCEPT; + + /* standard practice, label using the parent socket */ + sksec = selinux_sock(sk); + sid = sksec->sid; + } else + sid = SECINITSID_KERNEL; + if (selinux_netlbl_skbuff_setsid(skb, state->pf, sid) != 0) + return NF_DROP; + + return NF_ACCEPT; +} + + +static unsigned int selinux_ip_postroute_compat(struct sk_buff *skb, + const struct nf_hook_state *state) +{ + struct sock *sk; + struct sk_security_struct *sksec; + struct common_audit_data ad; + struct lsm_network_audit net; + u8 proto = 0; + + sk = skb_to_full_sk(skb); + if (sk == NULL) + return NF_ACCEPT; + sksec = selinux_sock(sk); + + ad_net_init_from_iif(&ad, &net, state->out->ifindex, state->pf); + if (selinux_parse_skb(skb, &ad, NULL, 0, &proto)) + return NF_DROP; + + if (selinux_secmark_enabled()) + if (avc_has_perm(sksec->sid, skb->secmark, + SECCLASS_PACKET, PACKET__SEND, &ad)) + return NF_DROP_ERR(-ECONNREFUSED); + + if (selinux_xfrm_postroute_last(sksec->sid, skb, &ad, proto)) + return NF_DROP_ERR(-ECONNREFUSED); + + return NF_ACCEPT; +} + +static unsigned int selinux_ip_postroute(void *priv, + struct sk_buff *skb, + const struct nf_hook_state *state) +{ + u16 family; + u32 secmark_perm; + u32 peer_sid; + int ifindex; + struct sock *sk; + struct common_audit_data ad; + struct lsm_network_audit net; + char *addrp; + int secmark_active, peerlbl_active; + + /* If any sort of compatibility mode is enabled then handoff processing + * to the selinux_ip_postroute_compat() function to deal with the + * special handling. We do this in an attempt to keep this function + * as fast and as clean as possible. */ + if (!selinux_policycap_netpeer()) + return selinux_ip_postroute_compat(skb, state); + + secmark_active = selinux_secmark_enabled(); + peerlbl_active = selinux_peerlbl_enabled(); + if (!secmark_active && !peerlbl_active) + return NF_ACCEPT; + + sk = skb_to_full_sk(skb); + +#ifdef CONFIG_XFRM + /* If skb->dst->xfrm is non-NULL then the packet is undergoing an IPsec + * packet transformation so allow the packet to pass without any checks + * since we'll have another chance to perform access control checks + * when the packet is on it's final way out. + * NOTE: there appear to be some IPv6 multicast cases where skb->dst + * is NULL, in this case go ahead and apply access control. + * NOTE: if this is a local socket (skb->sk != NULL) that is in the + * TCP listening state we cannot wait until the XFRM processing + * is done as we will miss out on the SA label if we do; + * unfortunately, this means more work, but it is only once per + * connection. */ + if (skb_dst(skb) != NULL && skb_dst(skb)->xfrm != NULL && + !(sk && sk_listener(sk))) + return NF_ACCEPT; +#endif + + family = state->pf; + if (sk == NULL) { + /* Without an associated socket the packet is either coming + * from the kernel or it is being forwarded; check the packet + * to determine which and if the packet is being forwarded + * query the packet directly to determine the security label. */ + if (skb->skb_iif) { + secmark_perm = PACKET__FORWARD_OUT; + if (selinux_skb_peerlbl_sid(skb, family, &peer_sid)) + return NF_DROP; + } else { + secmark_perm = PACKET__SEND; + peer_sid = SECINITSID_KERNEL; + } + } else if (sk_listener(sk)) { + /* Locally generated packet but the associated socket is in the + * listening state which means this is a SYN-ACK packet. In + * this particular case the correct security label is assigned + * to the connection/request_sock but unfortunately we can't + * query the request_sock as it isn't queued on the parent + * socket until after the SYN-ACK packet is sent; the only + * viable choice is to regenerate the label like we do in + * selinux_inet_conn_request(). See also selinux_ip_output() + * for similar problems. */ + u32 skb_sid; + struct sk_security_struct *sksec; + + sksec = selinux_sock(sk); + if (selinux_skb_peerlbl_sid(skb, family, &skb_sid)) + return NF_DROP; + /* At this point, if the returned skb peerlbl is SECSID_NULL + * and the packet has been through at least one XFRM + * transformation then we must be dealing with the "final" + * form of labeled IPsec packet; since we've already applied + * all of our access controls on this packet we can safely + * pass the packet. */ + if (skb_sid == SECSID_NULL) { + switch (family) { + case PF_INET: + if (IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED) + return NF_ACCEPT; + break; + case PF_INET6: + if (IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) + return NF_ACCEPT; + break; + default: + return NF_DROP_ERR(-ECONNREFUSED); + } + } + if (selinux_conn_sid(sksec->sid, skb_sid, &peer_sid)) + return NF_DROP; + secmark_perm = PACKET__SEND; + } else { + /* Locally generated packet, fetch the security label from the + * associated socket. */ + struct sk_security_struct *sksec = selinux_sock(sk); + peer_sid = sksec->sid; + secmark_perm = PACKET__SEND; + } + + ifindex = state->out->ifindex; + ad_net_init_from_iif(&ad, &net, ifindex, family); + if (selinux_parse_skb(skb, &ad, &addrp, 0, NULL)) + return NF_DROP; + + if (secmark_active) + if (avc_has_perm(peer_sid, skb->secmark, + SECCLASS_PACKET, secmark_perm, &ad)) + return NF_DROP_ERR(-ECONNREFUSED); + + if (peerlbl_active) { + u32 if_sid; + u32 node_sid; + + if (sel_netif_sid(state->net, ifindex, &if_sid)) + return NF_DROP; + if (avc_has_perm(peer_sid, if_sid, + SECCLASS_NETIF, NETIF__EGRESS, &ad)) + return NF_DROP_ERR(-ECONNREFUSED); + + if (sel_netnode_sid(addrp, family, &node_sid)) + return NF_DROP; + if (avc_has_perm(peer_sid, node_sid, + SECCLASS_NODE, NODE__SENDTO, &ad)) + return NF_DROP_ERR(-ECONNREFUSED); + } + + return NF_ACCEPT; +} +#endif /* CONFIG_NETFILTER */ + +static int nlmsg_sock_has_extended_perms(struct sock *sk, u32 perms, u16 nlmsg_type) +{ + struct sk_security_struct *sksec = selinux_sock(sk); + struct common_audit_data ad; + u8 driver; + u8 xperm; + + if (sock_skip_has_perm(sksec->sid)) + return 0; + + ad.type = LSM_AUDIT_DATA_NLMSGTYPE; + ad.u.nlmsg_type = nlmsg_type; + + driver = nlmsg_type >> 8; + xperm = nlmsg_type & 0xff; + + return avc_has_extended_perms(current_sid(), sksec->sid, sksec->sclass, + perms, driver, AVC_EXT_NLMSG, xperm, &ad); +} + +static int selinux_netlink_send(struct sock *sk, struct sk_buff *skb) +{ + int rc = 0; + unsigned int msg_len; + unsigned int data_len = skb->len; + unsigned char *data = skb->data; + struct nlmsghdr *nlh; + struct sk_security_struct *sksec = selinux_sock(sk); + u16 sclass = sksec->sclass; + u32 perm; + + while (data_len >= nlmsg_total_size(0)) { + nlh = (struct nlmsghdr *)data; + + /* NOTE: the nlmsg_len field isn't reliably set by some netlink + * users which means we can't reject skb's with bogus + * length fields; our solution is to follow what + * netlink_rcv_skb() does and simply skip processing at + * messages with length fields that are clearly junk + */ + if (nlh->nlmsg_len < NLMSG_HDRLEN || nlh->nlmsg_len > data_len) + return 0; + + rc = selinux_nlmsg_lookup(sclass, nlh->nlmsg_type, &perm); + if (rc == 0) { + if (selinux_policycap_netlink_xperm()) { + rc = nlmsg_sock_has_extended_perms( + sk, perm, nlh->nlmsg_type); + } else { + rc = sock_has_perm(sk, perm); + } + if (rc) + return rc; + } else if (rc == -EINVAL) { + /* -EINVAL is a missing msg/perm mapping */ + if (sclass == SECCLASS_NETLINK_TCPDIAG_SOCKET && + nlh->nlmsg_type == DCCPDIAG_GETSOCK) + pr_warn_once("SELinux: DCCP has been removed, pid=%d comm=%s\n", + task_pid_nr(current), current->comm); + else + pr_warn_ratelimited("SELinux: unrecognized netlink" + " message: protocol=%hu nlmsg_type=%hu sclass=%s" + " pid=%d comm=%s\n", + sk->sk_protocol, nlh->nlmsg_type, + secclass_map[sclass - 1].name, + task_pid_nr(current), current->comm); + if (enforcing_enabled() && + !security_get_allow_unknown()) + return rc; + rc = 0; + } else if (rc == -ENOENT) { + /* -ENOENT is a missing socket/class mapping, ignore */ + rc = 0; + } else { + return rc; + } + + /* move to the next message after applying netlink padding */ + msg_len = NLMSG_ALIGN(nlh->nlmsg_len); + if (msg_len >= data_len) + return 0; + data_len -= msg_len; + data += msg_len; + } + + return rc; +} + +static void ipc_init_security(struct ipc_security_struct *isec, u16 sclass) +{ + isec->sclass = sclass; + isec->sid = current_sid(); +} + +static int ipc_has_perm(struct kern_ipc_perm *ipc_perms, + u32 perms) +{ + struct ipc_security_struct *isec; + struct common_audit_data ad; + u32 sid = current_sid(); + + isec = selinux_ipc(ipc_perms); + + ad.type = LSM_AUDIT_DATA_IPC; + ad.u.ipc_id = ipc_perms->key; + + return avc_has_perm(sid, isec->sid, isec->sclass, perms, &ad); +} + +static int selinux_msg_msg_alloc_security(struct msg_msg *msg) +{ + struct msg_security_struct *msec; + + msec = selinux_msg_msg(msg); + msec->sid = SECINITSID_UNLABELED; + + return 0; +} + +/* message queue security operations */ +static int selinux_msg_queue_alloc_security(struct kern_ipc_perm *msq) +{ + struct ipc_security_struct *isec; + struct common_audit_data ad; + u32 sid = current_sid(); + + isec = selinux_ipc(msq); + ipc_init_security(isec, SECCLASS_MSGQ); + + ad.type = LSM_AUDIT_DATA_IPC; + ad.u.ipc_id = msq->key; + + return avc_has_perm(sid, isec->sid, SECCLASS_MSGQ, + MSGQ__CREATE, &ad); +} + +static int selinux_msg_queue_associate(struct kern_ipc_perm *msq, int msqflg) +{ + struct ipc_security_struct *isec; + struct common_audit_data ad; + u32 sid = current_sid(); + + isec = selinux_ipc(msq); + + ad.type = LSM_AUDIT_DATA_IPC; + ad.u.ipc_id = msq->key; + + return avc_has_perm(sid, isec->sid, SECCLASS_MSGQ, + MSGQ__ASSOCIATE, &ad); +} + +static int selinux_msg_queue_msgctl(struct kern_ipc_perm *msq, int cmd) +{ + u32 perms; + + switch (cmd) { + case IPC_INFO: + case MSG_INFO: + /* No specific object, just general system-wide information. */ + return avc_has_perm(current_sid(), SECINITSID_KERNEL, + SECCLASS_SYSTEM, SYSTEM__IPC_INFO, NULL); + case IPC_STAT: + case MSG_STAT: + case MSG_STAT_ANY: + perms = MSGQ__GETATTR | MSGQ__ASSOCIATE; + break; + case IPC_SET: + perms = MSGQ__SETATTR; + break; + case IPC_RMID: + perms = MSGQ__DESTROY; + break; + default: + return 0; + } + + return ipc_has_perm(msq, perms); +} + +static int selinux_msg_queue_msgsnd(struct kern_ipc_perm *msq, struct msg_msg *msg, int msqflg) +{ + struct ipc_security_struct *isec; + struct msg_security_struct *msec; + struct common_audit_data ad; + u32 sid = current_sid(); + int rc; + + isec = selinux_ipc(msq); + msec = selinux_msg_msg(msg); + + /* + * First time through, need to assign label to the message + */ + if (msec->sid == SECINITSID_UNLABELED) { + /* + * Compute new sid based on current process and + * message queue this message will be stored in + */ + rc = security_transition_sid(sid, isec->sid, + SECCLASS_MSG, NULL, &msec->sid); + if (rc) + return rc; + } + + ad.type = LSM_AUDIT_DATA_IPC; + ad.u.ipc_id = msq->key; + + /* Can this process write to the queue? */ + rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ, + MSGQ__WRITE, &ad); + if (!rc) + /* Can this process send the message */ + rc = avc_has_perm(sid, msec->sid, SECCLASS_MSG, + MSG__SEND, &ad); + if (!rc) + /* Can the message be put in the queue? */ + rc = avc_has_perm(msec->sid, isec->sid, SECCLASS_MSGQ, + MSGQ__ENQUEUE, &ad); + + return rc; +} + +static int selinux_msg_queue_msgrcv(struct kern_ipc_perm *msq, struct msg_msg *msg, + struct task_struct *target, + long type, int mode) +{ + struct ipc_security_struct *isec; + struct msg_security_struct *msec; + struct common_audit_data ad; + u32 sid = task_sid_obj(target); + int rc; + + isec = selinux_ipc(msq); + msec = selinux_msg_msg(msg); + + ad.type = LSM_AUDIT_DATA_IPC; + ad.u.ipc_id = msq->key; + + rc = avc_has_perm(sid, isec->sid, + SECCLASS_MSGQ, MSGQ__READ, &ad); + if (!rc) + rc = avc_has_perm(sid, msec->sid, + SECCLASS_MSG, MSG__RECEIVE, &ad); + return rc; +} + +/* Shared Memory security operations */ +static int selinux_shm_alloc_security(struct kern_ipc_perm *shp) +{ + struct ipc_security_struct *isec; + struct common_audit_data ad; + u32 sid = current_sid(); + + isec = selinux_ipc(shp); + ipc_init_security(isec, SECCLASS_SHM); + + ad.type = LSM_AUDIT_DATA_IPC; + ad.u.ipc_id = shp->key; + + return avc_has_perm(sid, isec->sid, SECCLASS_SHM, + SHM__CREATE, &ad); +} + +static int selinux_shm_associate(struct kern_ipc_perm *shp, int shmflg) +{ + struct ipc_security_struct *isec; + struct common_audit_data ad; + u32 sid = current_sid(); + + isec = selinux_ipc(shp); + + ad.type = LSM_AUDIT_DATA_IPC; + ad.u.ipc_id = shp->key; + + return avc_has_perm(sid, isec->sid, SECCLASS_SHM, + SHM__ASSOCIATE, &ad); +} + +/* Note, at this point, shp is locked down */ +static int selinux_shm_shmctl(struct kern_ipc_perm *shp, int cmd) +{ + u32 perms; + + switch (cmd) { + case IPC_INFO: + case SHM_INFO: + /* No specific object, just general system-wide information. */ + return avc_has_perm(current_sid(), SECINITSID_KERNEL, + SECCLASS_SYSTEM, SYSTEM__IPC_INFO, NULL); + case IPC_STAT: + case SHM_STAT: + case SHM_STAT_ANY: + perms = SHM__GETATTR | SHM__ASSOCIATE; + break; + case IPC_SET: + perms = SHM__SETATTR; + break; + case SHM_LOCK: + case SHM_UNLOCK: + perms = SHM__LOCK; + break; + case IPC_RMID: + perms = SHM__DESTROY; + break; + default: + return 0; + } + + return ipc_has_perm(shp, perms); +} + +static int selinux_shm_shmat(struct kern_ipc_perm *shp, + char __user *shmaddr, int shmflg) +{ + u32 perms; + + if (shmflg & SHM_RDONLY) + perms = SHM__READ; + else + perms = SHM__READ | SHM__WRITE; + + return ipc_has_perm(shp, perms); +} + +/* Semaphore security operations */ +static int selinux_sem_alloc_security(struct kern_ipc_perm *sma) +{ + struct ipc_security_struct *isec; + struct common_audit_data ad; + u32 sid = current_sid(); + + isec = selinux_ipc(sma); + ipc_init_security(isec, SECCLASS_SEM); + + ad.type = LSM_AUDIT_DATA_IPC; + ad.u.ipc_id = sma->key; + + return avc_has_perm(sid, isec->sid, SECCLASS_SEM, + SEM__CREATE, &ad); +} + +static int selinux_sem_associate(struct kern_ipc_perm *sma, int semflg) +{ + struct ipc_security_struct *isec; + struct common_audit_data ad; + u32 sid = current_sid(); + + isec = selinux_ipc(sma); + + ad.type = LSM_AUDIT_DATA_IPC; + ad.u.ipc_id = sma->key; + + return avc_has_perm(sid, isec->sid, SECCLASS_SEM, + SEM__ASSOCIATE, &ad); +} + +/* Note, at this point, sma is locked down */ +static int selinux_sem_semctl(struct kern_ipc_perm *sma, int cmd) +{ + int err; + u32 perms; + + switch (cmd) { + case IPC_INFO: + case SEM_INFO: + /* No specific object, just general system-wide information. */ + return avc_has_perm(current_sid(), SECINITSID_KERNEL, + SECCLASS_SYSTEM, SYSTEM__IPC_INFO, NULL); + case GETPID: + case GETNCNT: + case GETZCNT: + perms = SEM__GETATTR; + break; + case GETVAL: + case GETALL: + perms = SEM__READ; + break; + case SETVAL: + case SETALL: + perms = SEM__WRITE; + break; + case IPC_RMID: + perms = SEM__DESTROY; + break; + case IPC_SET: + perms = SEM__SETATTR; + break; + case IPC_STAT: + case SEM_STAT: + case SEM_STAT_ANY: + perms = SEM__GETATTR | SEM__ASSOCIATE; + break; + default: + return 0; + } + + err = ipc_has_perm(sma, perms); + return err; +} + +static int selinux_sem_semop(struct kern_ipc_perm *sma, + struct sembuf *sops, unsigned nsops, int alter) +{ + u32 perms; + + if (alter) + perms = SEM__READ | SEM__WRITE; + else + perms = SEM__READ; + + return ipc_has_perm(sma, perms); +} + +static int selinux_ipc_permission(struct kern_ipc_perm *ipcp, short flag) +{ + u32 av = 0; + + av = 0; + if (flag & S_IRUGO) + av |= IPC__UNIX_READ; + if (flag & S_IWUGO) + av |= IPC__UNIX_WRITE; + + if (av == 0) + return 0; + + return ipc_has_perm(ipcp, av); +} + +static void selinux_ipc_getlsmprop(struct kern_ipc_perm *ipcp, + struct lsm_prop *prop) +{ + struct ipc_security_struct *isec = selinux_ipc(ipcp); + prop->selinux.secid = isec->sid; +} + +static void selinux_d_instantiate(struct dentry *dentry, struct inode *inode) +{ + if (inode) + inode_doinit_with_dentry(inode, dentry); +} + +static int selinux_lsm_getattr(unsigned int attr, struct task_struct *p, + char **value) +{ + const struct cred_security_struct *crsec; + int error; + u32 sid; + u32 len; + + rcu_read_lock(); + crsec = selinux_cred(__task_cred(p)); + if (p != current) { + error = avc_has_perm(current_sid(), crsec->sid, + SECCLASS_PROCESS, PROCESS__GETATTR, NULL); + if (error) + goto err_unlock; + } + switch (attr) { + case LSM_ATTR_CURRENT: + sid = crsec->sid; + break; + case LSM_ATTR_PREV: + sid = crsec->osid; + break; + case LSM_ATTR_EXEC: + sid = crsec->exec_sid; + break; + case LSM_ATTR_FSCREATE: + sid = crsec->create_sid; + break; + case LSM_ATTR_KEYCREATE: + sid = crsec->keycreate_sid; + break; + case LSM_ATTR_SOCKCREATE: + sid = crsec->sockcreate_sid; + break; + default: + error = -EOPNOTSUPP; + goto err_unlock; + } + rcu_read_unlock(); + + if (sid == SECSID_NULL) { + *value = NULL; + return 0; + } + + error = security_sid_to_context(sid, value, &len); + if (error) + return error; + return len; + +err_unlock: + rcu_read_unlock(); + return error; +} + +static int selinux_lsm_setattr(u64 attr, void *value, size_t size) +{ + struct cred_security_struct *crsec; + struct cred *new; + u32 mysid = current_sid(), sid = 0, ptsid; + int error; + char *str = value; + + /* + * Basic control over ability to set these attributes at all. + */ + switch (attr) { + case LSM_ATTR_EXEC: + error = avc_has_perm(mysid, mysid, SECCLASS_PROCESS, + PROCESS__SETEXEC, NULL); + break; + case LSM_ATTR_FSCREATE: + error = avc_has_perm(mysid, mysid, SECCLASS_PROCESS, + PROCESS__SETFSCREATE, NULL); + break; + case LSM_ATTR_KEYCREATE: + error = avc_has_perm(mysid, mysid, SECCLASS_PROCESS, + PROCESS__SETKEYCREATE, NULL); + break; + case LSM_ATTR_SOCKCREATE: + error = avc_has_perm(mysid, mysid, SECCLASS_PROCESS, + PROCESS__SETSOCKCREATE, NULL); + break; + case LSM_ATTR_CURRENT: + error = avc_has_perm(mysid, mysid, SECCLASS_PROCESS, + PROCESS__SETCURRENT, NULL); + break; + default: + error = -EOPNOTSUPP; + break; + } + if (error) + return error; + + /* Obtain a SID for the context, if one was specified. */ + if (size && str[0] && str[0] != '\n') { + if (str[size-1] == '\n') { + str[size-1] = 0; + size--; + } + error = security_context_to_sid(value, size, + &sid, GFP_KERNEL); + if (error == -EINVAL && attr == LSM_ATTR_FSCREATE) { + if (!has_cap_mac_admin(true)) { + struct audit_buffer *ab; + size_t audit_size; + + /* We strip a nul only if it is at the end, + * otherwise the context contains a nul and + * we should audit that */ + if (str[size - 1] == '\0') + audit_size = size - 1; + else + audit_size = size; + ab = audit_log_start(audit_context(), + GFP_ATOMIC, + AUDIT_SELINUX_ERR); + if (!ab) + return error; + audit_log_format(ab, "op=fscreate invalid_context="); + audit_log_n_untrustedstring(ab, value, + audit_size); + audit_log_end(ab); + + return error; + } + error = security_context_to_sid_force(value, size, + &sid); + } + if (error) + return error; + } + + new = prepare_creds(); + if (!new) + return -ENOMEM; + + /* Permission checking based on the specified context is + performed during the actual operation (execve, + open/mkdir/...), when we know the full context of the + operation. See selinux_bprm_creds_for_exec for the execve + checks and may_create for the file creation checks. The + operation will then fail if the context is not permitted. */ + crsec = selinux_cred(new); + if (attr == LSM_ATTR_EXEC) { + crsec->exec_sid = sid; + } else if (attr == LSM_ATTR_FSCREATE) { + crsec->create_sid = sid; + } else if (attr == LSM_ATTR_KEYCREATE) { + if (sid) { + error = avc_has_perm(mysid, sid, + SECCLASS_KEY, KEY__CREATE, NULL); + if (error) + goto abort_change; + } + crsec->keycreate_sid = sid; + } else if (attr == LSM_ATTR_SOCKCREATE) { + crsec->sockcreate_sid = sid; + } else if (attr == LSM_ATTR_CURRENT) { + error = -EINVAL; + if (sid == 0) + goto abort_change; + + if (!current_is_single_threaded()) { + error = security_bounded_transition(crsec->sid, sid); + if (error) + goto abort_change; + } + + /* Check permissions for the transition. */ + error = avc_has_perm(crsec->sid, sid, SECCLASS_PROCESS, + PROCESS__DYNTRANSITION, NULL); + if (error) + goto abort_change; + + /* Check for ptracing, and update the task SID if ok. + Otherwise, leave SID unchanged and fail. */ + ptsid = ptrace_parent_sid(); + if (ptsid != 0) { + error = avc_has_perm(ptsid, sid, SECCLASS_PROCESS, + PROCESS__PTRACE, NULL); + if (error) + goto abort_change; + } + + crsec->sid = sid; + } else { + error = -EINVAL; + goto abort_change; + } + + commit_creds(new); + return size; + +abort_change: + abort_creds(new); + return error; +} + +/** + * selinux_getselfattr - Get SELinux current task attributes + * @attr: the requested attribute + * @ctx: buffer to receive the result + * @size: buffer size (input), buffer size used (output) + * @flags: unused + * + * Fill the passed user space @ctx with the details of the requested + * attribute. + * + * Returns the number of attributes on success, an error code otherwise. + * There will only ever be one attribute. + */ +static int selinux_getselfattr(unsigned int attr, struct lsm_ctx __user *ctx, + u32 *size, u32 flags) +{ + int rc; + char *val = NULL; + int val_len; + + val_len = selinux_lsm_getattr(attr, current, &val); + if (val_len < 0) + return val_len; + rc = lsm_fill_user_ctx(ctx, size, val, val_len, LSM_ID_SELINUX, 0); + kfree(val); + return (!rc ? 1 : rc); +} + +static int selinux_setselfattr(unsigned int attr, struct lsm_ctx *ctx, + u32 size, u32 flags) +{ + int rc; + + rc = selinux_lsm_setattr(attr, ctx->ctx, ctx->ctx_len); + if (rc > 0) + return 0; + return rc; +} + +static int selinux_getprocattr(struct task_struct *p, + const char *name, char **value) +{ + unsigned int attr = lsm_name_to_attr(name); + int rc; + + if (attr) { + rc = selinux_lsm_getattr(attr, p, value); + if (rc != -EOPNOTSUPP) + return rc; + } + + return -EINVAL; +} + +static int selinux_setprocattr(const char *name, void *value, size_t size) +{ + int attr = lsm_name_to_attr(name); + + if (attr) + return selinux_lsm_setattr(attr, value, size); + return -EINVAL; +} + +static int selinux_ismaclabel(const char *name) +{ + return (strcmp(name, XATTR_SELINUX_SUFFIX) == 0); +} + +static int selinux_secid_to_secctx(u32 secid, struct lsm_context *cp) +{ + u32 seclen; + int ret; + + if (cp) { + cp->id = LSM_ID_SELINUX; + ret = security_sid_to_context(secid, &cp->context, &cp->len); + if (ret < 0) + return ret; + return cp->len; + } + ret = security_sid_to_context(secid, NULL, &seclen); + if (ret < 0) + return ret; + return seclen; +} + +static int selinux_lsmprop_to_secctx(struct lsm_prop *prop, + struct lsm_context *cp) +{ + return selinux_secid_to_secctx(prop->selinux.secid, cp); +} + +static int selinux_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid) +{ + return security_context_to_sid(secdata, seclen, + secid, GFP_KERNEL); +} + +static void selinux_release_secctx(struct lsm_context *cp) +{ + if (cp->id == LSM_ID_SELINUX) { + kfree(cp->context); + cp->context = NULL; + cp->id = LSM_ID_UNDEF; + } +} + +static void selinux_inode_invalidate_secctx(struct inode *inode) +{ + struct inode_security_struct *isec = selinux_inode(inode); + + spin_lock(&isec->lock); + isec->initialized = LABEL_INVALID; + spin_unlock(&isec->lock); +} + +/* + * called with inode->i_mutex locked + */ +static int selinux_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen) +{ + int rc = selinux_inode_setsecurity(inode, XATTR_SELINUX_SUFFIX, + ctx, ctxlen, 0); + /* Do not return error when suppressing label (SBLABEL_MNT not set). */ + return rc == -EOPNOTSUPP ? 0 : rc; +} + +/* + * called with inode->i_mutex locked + */ +static int selinux_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen) +{ + return __vfs_setxattr_locked(&nop_mnt_idmap, dentry, XATTR_NAME_SELINUX, + ctx, ctxlen, 0, NULL); +} + +static int selinux_inode_getsecctx(struct inode *inode, struct lsm_context *cp) +{ + int len; + len = selinux_inode_getsecurity(&nop_mnt_idmap, inode, + XATTR_SELINUX_SUFFIX, + (void **)&cp->context, true); + if (len < 0) + return len; + cp->len = len; + cp->id = LSM_ID_SELINUX; + return 0; +} +#ifdef CONFIG_KEYS + +static int selinux_key_alloc(struct key *k, const struct cred *cred, + unsigned long flags) +{ + const struct cred_security_struct *crsec; + struct key_security_struct *ksec = selinux_key(k); + + crsec = selinux_cred(cred); + if (crsec->keycreate_sid) + ksec->sid = crsec->keycreate_sid; + else + ksec->sid = crsec->sid; + + return 0; +} + +static int selinux_key_permission(key_ref_t key_ref, + const struct cred *cred, + enum key_need_perm need_perm) +{ + struct key *key; + struct key_security_struct *ksec; + u32 perm, sid; + + switch (need_perm) { + case KEY_NEED_VIEW: + perm = KEY__VIEW; + break; + case KEY_NEED_READ: + perm = KEY__READ; + break; + case KEY_NEED_WRITE: + perm = KEY__WRITE; + break; + case KEY_NEED_SEARCH: + perm = KEY__SEARCH; + break; + case KEY_NEED_LINK: + perm = KEY__LINK; + break; + case KEY_NEED_SETATTR: + perm = KEY__SETATTR; + break; + case KEY_NEED_UNLINK: + case KEY_SYSADMIN_OVERRIDE: + case KEY_AUTHTOKEN_OVERRIDE: + case KEY_DEFER_PERM_CHECK: + return 0; + default: + WARN_ON(1); + return -EPERM; + + } + + sid = cred_sid(cred); + key = key_ref_to_ptr(key_ref); + ksec = selinux_key(key); + + return avc_has_perm(sid, ksec->sid, SECCLASS_KEY, perm, NULL); +} + +static int selinux_key_getsecurity(struct key *key, char **_buffer) +{ + struct key_security_struct *ksec = selinux_key(key); + char *context = NULL; + unsigned len; + int rc; + + rc = security_sid_to_context(ksec->sid, + &context, &len); + if (!rc) + rc = len; + *_buffer = context; + return rc; +} + +#ifdef CONFIG_KEY_NOTIFICATIONS +static int selinux_watch_key(struct key *key) +{ + struct key_security_struct *ksec = selinux_key(key); + u32 sid = current_sid(); + + return avc_has_perm(sid, ksec->sid, SECCLASS_KEY, KEY__VIEW, NULL); +} +#endif +#endif + +#ifdef CONFIG_SECURITY_INFINIBAND +static int selinux_ib_pkey_access(void *ib_sec, u64 subnet_prefix, u16 pkey_val) +{ + struct common_audit_data ad; + int err; + u32 sid = 0; + struct ib_security_struct *sec = ib_sec; + struct lsm_ibpkey_audit ibpkey; + + err = sel_ib_pkey_sid(subnet_prefix, pkey_val, &sid); + if (err) + return err; + + ad.type = LSM_AUDIT_DATA_IBPKEY; + ibpkey.subnet_prefix = subnet_prefix; + ibpkey.pkey = pkey_val; + ad.u.ibpkey = &ibpkey; + return avc_has_perm(sec->sid, sid, + SECCLASS_INFINIBAND_PKEY, + INFINIBAND_PKEY__ACCESS, &ad); +} + +static int selinux_ib_endport_manage_subnet(void *ib_sec, const char *dev_name, + u8 port_num) +{ + struct common_audit_data ad; + int err; + u32 sid = 0; + struct ib_security_struct *sec = ib_sec; + struct lsm_ibendport_audit ibendport; + + err = security_ib_endport_sid(dev_name, port_num, + &sid); + + if (err) + return err; + + ad.type = LSM_AUDIT_DATA_IBENDPORT; + ibendport.dev_name = dev_name; + ibendport.port = port_num; + ad.u.ibendport = &ibendport; + return avc_has_perm(sec->sid, sid, + SECCLASS_INFINIBAND_ENDPORT, + INFINIBAND_ENDPORT__MANAGE_SUBNET, &ad); +} + +static int selinux_ib_alloc_security(void *ib_sec) +{ + struct ib_security_struct *sec = selinux_ib(ib_sec); + + sec->sid = current_sid(); + return 0; +} +#endif + +#ifdef CONFIG_BPF_SYSCALL +static int selinux_bpf(int cmd, union bpf_attr *attr, + unsigned int size, bool kernel) +{ + u32 sid = current_sid(); + int ret; + + if (selinux_policycap_bpf_token_perms()) + return 0; + + switch (cmd) { + case BPF_MAP_CREATE: + ret = avc_has_perm(sid, sid, SECCLASS_BPF, BPF__MAP_CREATE, + NULL); + break; + case BPF_PROG_LOAD: + ret = avc_has_perm(sid, sid, SECCLASS_BPF, BPF__PROG_LOAD, + NULL); + break; + default: + ret = 0; + break; + } + + return ret; +} + +static u32 bpf_map_fmode_to_av(fmode_t fmode) +{ + u32 av = 0; + + if (fmode & FMODE_READ) + av |= BPF__MAP_READ; + if (fmode & FMODE_WRITE) + av |= BPF__MAP_WRITE; + return av; +} + +/* This function will check the file pass through unix socket or binder to see + * if it is a bpf related object. And apply corresponding checks on the bpf + * object based on the type. The bpf maps and programs, not like other files and + * socket, are using a shared anonymous inode inside the kernel as their inode. + * So checking that inode cannot identify if the process have privilege to + * access the bpf object and that's why we have to add this additional check in + * selinux_file_receive and selinux_binder_transfer_files. + */ +static int bpf_fd_pass(const struct file *file, u32 sid) +{ + struct bpf_security_struct *bpfsec; + struct bpf_prog *prog; + struct bpf_map *map; + int ret; + + if (file->f_op == &bpf_map_fops) { + map = file->private_data; + bpfsec = selinux_bpf_map_security(map); + ret = avc_has_perm(sid, bpfsec->sid, SECCLASS_BPF, + bpf_map_fmode_to_av(file->f_mode), NULL); + if (ret) + return ret; + } else if (file->f_op == &bpf_prog_fops) { + prog = file->private_data; + bpfsec = selinux_bpf_prog_security(prog); + ret = avc_has_perm(sid, bpfsec->sid, SECCLASS_BPF, + BPF__PROG_RUN, NULL); + if (ret) + return ret; + } + return 0; +} + +static int selinux_bpf_map(struct bpf_map *map, fmode_t fmode) +{ + u32 sid = current_sid(); + struct bpf_security_struct *bpfsec; + + bpfsec = selinux_bpf_map_security(map); + return avc_has_perm(sid, bpfsec->sid, SECCLASS_BPF, + bpf_map_fmode_to_av(fmode), NULL); +} + +static int selinux_bpf_prog(struct bpf_prog *prog) +{ + u32 sid = current_sid(); + struct bpf_security_struct *bpfsec; + + bpfsec = selinux_bpf_prog_security(prog); + return avc_has_perm(sid, bpfsec->sid, SECCLASS_BPF, + BPF__PROG_RUN, NULL); +} + +static u32 selinux_bpffs_creator_sid(u32 fd) +{ + struct path path; + struct super_block *sb; + struct superblock_security_struct *sbsec; + + CLASS(fd, f)(fd); + + if (fd_empty(f)) + return SECSID_NULL; + + path = fd_file(f)->f_path; + sb = path.dentry->d_sb; + sbsec = selinux_superblock(sb); + + return sbsec->creator_sid; +} + +static int selinux_bpf_map_create(struct bpf_map *map, union bpf_attr *attr, + struct bpf_token *token, bool kernel) +{ + struct bpf_security_struct *bpfsec; + u32 ssid; + + bpfsec = selinux_bpf_map_security(map); + bpfsec->sid = current_sid(); + + if (!token) + ssid = bpfsec->sid; + else + ssid = selinux_bpffs_creator_sid(attr->map_token_fd); + + return avc_has_perm(ssid, bpfsec->sid, SECCLASS_BPF, BPF__MAP_CREATE, + NULL); +} + +static int selinux_bpf_prog_load(struct bpf_prog *prog, union bpf_attr *attr, + struct bpf_token *token, bool kernel) +{ + struct bpf_security_struct *bpfsec; + u32 ssid; + + bpfsec = selinux_bpf_prog_security(prog); + bpfsec->sid = current_sid(); + + if (!token) + ssid = bpfsec->sid; + else + ssid = selinux_bpffs_creator_sid(attr->prog_token_fd); + + return avc_has_perm(ssid, bpfsec->sid, SECCLASS_BPF, BPF__PROG_LOAD, + NULL); +} + +#define bpf_token_cmd(T, C) \ + ((T)->allowed_cmds & (1ULL << (C))) + +static int selinux_bpf_token_create(struct bpf_token *token, + union bpf_attr *attr, + const struct path *path) +{ + struct bpf_security_struct *bpfsec; + u32 sid = selinux_bpffs_creator_sid(attr->token_create.bpffs_fd); + int err; + + bpfsec = selinux_bpf_token_security(token); + bpfsec->sid = current_sid(); + bpfsec->grantor_sid = sid; + + bpfsec->perms = 0; + /** + * 'token->allowed_cmds' is a bit mask of allowed commands + * Convert the BPF command enum to a bitmask representing its position + * in the allowed_cmds bitmap. + */ + if (bpf_token_cmd(token, BPF_MAP_CREATE)) { + err = avc_has_perm(bpfsec->sid, sid, SECCLASS_BPF, + BPF__MAP_CREATE_AS, NULL); + if (err) + return err; + bpfsec->perms |= BPF__MAP_CREATE; + } + if (bpf_token_cmd(token, BPF_PROG_LOAD)) { + err = avc_has_perm(bpfsec->sid, sid, SECCLASS_BPF, + BPF__PROG_LOAD_AS, NULL); + if (err) + return err; + bpfsec->perms |= BPF__PROG_LOAD; + } + + return 0; +} + +static int selinux_bpf_token_cmd(const struct bpf_token *token, + enum bpf_cmd cmd) +{ + struct bpf_security_struct *bpfsec; + + bpfsec = token->security; + switch (cmd) { + case BPF_MAP_CREATE: + if (!(bpfsec->perms & BPF__MAP_CREATE)) + return -EACCES; + break; + case BPF_PROG_LOAD: + if (!(bpfsec->perms & BPF__PROG_LOAD)) + return -EACCES; + break; + default: + break; + } + + return 0; +} + +static int selinux_bpf_token_capable(const struct bpf_token *token, int cap) +{ + u16 sclass; + struct bpf_security_struct *bpfsec = token->security; + bool initns = (token->userns == &init_user_ns); + u32 av = CAP_TO_MASK(cap); + + switch (CAP_TO_INDEX(cap)) { + case 0: + sclass = initns ? SECCLASS_CAPABILITY : SECCLASS_CAP_USERNS; + break; + case 1: + sclass = initns ? SECCLASS_CAPABILITY2 : SECCLASS_CAP2_USERNS; + break; + default: + pr_err("SELinux: out of range capability %d\n", cap); + return -EINVAL; + } + + return avc_has_perm(current_sid(), bpfsec->grantor_sid, sclass, av, + NULL); +} +#endif + +#ifdef CONFIG_PERF_EVENTS +static int selinux_perf_event_open(int type) +{ + u32 requested, sid = current_sid(); + + if (type == PERF_SECURITY_OPEN) + requested = PERF_EVENT__OPEN; + else if (type == PERF_SECURITY_CPU) + requested = PERF_EVENT__CPU; + else if (type == PERF_SECURITY_KERNEL) + requested = PERF_EVENT__KERNEL; + else if (type == PERF_SECURITY_TRACEPOINT) + requested = PERF_EVENT__TRACEPOINT; + else + return -EINVAL; + + return avc_has_perm(sid, sid, SECCLASS_PERF_EVENT, + requested, NULL); +} + +static int selinux_perf_event_alloc(struct perf_event *event) +{ + struct perf_event_security_struct *perfsec; + + perfsec = selinux_perf_event(event->security); + perfsec->sid = current_sid(); + + return 0; +} + +static int selinux_perf_event_read(struct perf_event *event) +{ + struct perf_event_security_struct *perfsec = event->security; + u32 sid = current_sid(); + + return avc_has_perm(sid, perfsec->sid, + SECCLASS_PERF_EVENT, PERF_EVENT__READ, NULL); +} + +static int selinux_perf_event_write(struct perf_event *event) +{ + struct perf_event_security_struct *perfsec = event->security; + u32 sid = current_sid(); + + return avc_has_perm(sid, perfsec->sid, + SECCLASS_PERF_EVENT, PERF_EVENT__WRITE, NULL); +} +#endif + +#ifdef CONFIG_IO_URING +/** + * selinux_uring_override_creds - check the requested cred override + * @new: the target creds + * + * Check to see if the current task is allowed to override it's credentials + * to service an io_uring operation. + */ +static int selinux_uring_override_creds(const struct cred *new) +{ + return avc_has_perm(current_sid(), cred_sid(new), + SECCLASS_IO_URING, IO_URING__OVERRIDE_CREDS, NULL); +} + +/** + * selinux_uring_sqpoll - check if a io_uring polling thread can be created + * + * Check to see if the current task is allowed to create a new io_uring + * kernel polling thread. + */ +static int selinux_uring_sqpoll(void) +{ + u32 sid = current_sid(); + + return avc_has_perm(sid, sid, + SECCLASS_IO_URING, IO_URING__SQPOLL, NULL); +} + +/** + * selinux_uring_cmd - check if IORING_OP_URING_CMD is allowed + * @ioucmd: the io_uring command structure + * + * Check to see if the current domain is allowed to execute an + * IORING_OP_URING_CMD against the device/file specified in @ioucmd. + * + */ +static int selinux_uring_cmd(struct io_uring_cmd *ioucmd) +{ + struct file *file = ioucmd->file; + struct inode *inode = file_inode(file); + struct inode_security_struct *isec = selinux_inode(inode); + struct common_audit_data ad; + + ad.type = LSM_AUDIT_DATA_FILE; + ad.u.file = file; + + return avc_has_perm(current_sid(), isec->sid, + SECCLASS_IO_URING, IO_URING__CMD, &ad); +} + +/** + * selinux_uring_allowed - check if io_uring_setup() can be called + * + * Check to see if the current task is allowed to call io_uring_setup(). + */ +static int selinux_uring_allowed(void) +{ + u32 sid = current_sid(); + + return avc_has_perm(sid, sid, SECCLASS_IO_URING, IO_URING__ALLOWED, + NULL); +} +#endif /* CONFIG_IO_URING */ + +static const struct lsm_id selinux_lsmid = { + .name = "selinux", + .id = LSM_ID_SELINUX, +}; + +struct lsm_blob_sizes selinux_blob_sizes __ro_after_init = { + .lbs_cred = sizeof(struct cred_security_struct), + .lbs_task = sizeof(struct task_security_struct), + .lbs_file = sizeof(struct file_security_struct), + .lbs_backing_file = sizeof(struct backing_file_security_struct), + .lbs_inode = sizeof(struct inode_security_struct), + .lbs_ipc = sizeof(struct ipc_security_struct), + .lbs_key = sizeof(struct key_security_struct), + .lbs_msg_msg = sizeof(struct msg_security_struct), +#ifdef CONFIG_PERF_EVENTS + .lbs_perf_event = sizeof(struct perf_event_security_struct), +#endif + .lbs_sock = sizeof(struct sk_security_struct), + .lbs_superblock = sizeof(struct superblock_security_struct), + .lbs_xattr_count = SELINUX_INODE_INIT_XATTRS, + .lbs_tun_dev = sizeof(struct tun_security_struct), + .lbs_ib = sizeof(struct ib_security_struct), + .lbs_bpf_map = sizeof(struct bpf_security_struct), + .lbs_bpf_prog = sizeof(struct bpf_security_struct), + .lbs_bpf_token = sizeof(struct bpf_security_struct), +}; + +/* + * IMPORTANT NOTE: When adding new hooks, please be careful to keep this order: + * 1. any hooks that don't belong to (2.) or (3.) below, + * 2. hooks that both access structures allocated by other hooks, and allocate + * structures that can be later accessed by other hooks (mostly "cloning" + * hooks), + * 3. hooks that only allocate structures that can be later accessed by other + * hooks ("allocating" hooks). + * + * Please follow block comment delimiters in the list to keep this order. + */ +static struct security_hook_list selinux_hooks[] __ro_after_init = { + LSM_HOOK_INIT(binder_set_context_mgr, selinux_binder_set_context_mgr), + LSM_HOOK_INIT(binder_transaction, selinux_binder_transaction), + LSM_HOOK_INIT(binder_transfer_binder, selinux_binder_transfer_binder), + LSM_HOOK_INIT(binder_transfer_file, selinux_binder_transfer_file), + + LSM_HOOK_INIT(ptrace_access_check, selinux_ptrace_access_check), + LSM_HOOK_INIT(ptrace_traceme, selinux_ptrace_traceme), + LSM_HOOK_INIT(capget, selinux_capget), + LSM_HOOK_INIT(capset, selinux_capset), + LSM_HOOK_INIT(capable, selinux_capable), + LSM_HOOK_INIT(quotactl, selinux_quotactl), + LSM_HOOK_INIT(quota_on, selinux_quota_on), + LSM_HOOK_INIT(syslog, selinux_syslog), + LSM_HOOK_INIT(vm_enough_memory, selinux_vm_enough_memory), + + LSM_HOOK_INIT(netlink_send, selinux_netlink_send), + + LSM_HOOK_INIT(bprm_creds_for_exec, selinux_bprm_creds_for_exec), + LSM_HOOK_INIT(bprm_committing_creds, selinux_bprm_committing_creds), + LSM_HOOK_INIT(bprm_committed_creds, selinux_bprm_committed_creds), + + LSM_HOOK_INIT(sb_free_mnt_opts, selinux_free_mnt_opts), + LSM_HOOK_INIT(sb_mnt_opts_compat, selinux_sb_mnt_opts_compat), + LSM_HOOK_INIT(sb_remount, selinux_sb_remount), + LSM_HOOK_INIT(sb_kern_mount, selinux_sb_kern_mount), + LSM_HOOK_INIT(sb_show_options, selinux_sb_show_options), + LSM_HOOK_INIT(sb_statfs, selinux_sb_statfs), + LSM_HOOK_INIT(sb_mount, selinux_mount), + LSM_HOOK_INIT(sb_umount, selinux_umount), + LSM_HOOK_INIT(sb_set_mnt_opts, selinux_set_mnt_opts), + LSM_HOOK_INIT(sb_clone_mnt_opts, selinux_sb_clone_mnt_opts), + + LSM_HOOK_INIT(move_mount, selinux_move_mount), + + LSM_HOOK_INIT(dentry_init_security, selinux_dentry_init_security), + LSM_HOOK_INIT(dentry_create_files_as, selinux_dentry_create_files_as), + + LSM_HOOK_INIT(inode_free_security, selinux_inode_free_security), + LSM_HOOK_INIT(inode_init_security, selinux_inode_init_security), + LSM_HOOK_INIT(inode_init_security_anon, selinux_inode_init_security_anon), + LSM_HOOK_INIT(inode_create, selinux_inode_create), + LSM_HOOK_INIT(inode_link, selinux_inode_link), + LSM_HOOK_INIT(inode_unlink, selinux_inode_unlink), + LSM_HOOK_INIT(inode_symlink, selinux_inode_symlink), + LSM_HOOK_INIT(inode_mkdir, selinux_inode_mkdir), + LSM_HOOK_INIT(inode_rmdir, selinux_inode_rmdir), + LSM_HOOK_INIT(inode_mknod, selinux_inode_mknod), + LSM_HOOK_INIT(inode_rename, selinux_inode_rename), + LSM_HOOK_INIT(inode_readlink, selinux_inode_readlink), + LSM_HOOK_INIT(inode_follow_link, selinux_inode_follow_link), + LSM_HOOK_INIT(inode_permission, selinux_inode_permission), + LSM_HOOK_INIT(inode_setattr, selinux_inode_setattr), + LSM_HOOK_INIT(inode_getattr, selinux_inode_getattr), + LSM_HOOK_INIT(inode_xattr_skipcap, selinux_inode_xattr_skipcap), + LSM_HOOK_INIT(inode_setxattr, selinux_inode_setxattr), + LSM_HOOK_INIT(inode_post_setxattr, selinux_inode_post_setxattr), + LSM_HOOK_INIT(inode_getxattr, selinux_inode_getxattr), + LSM_HOOK_INIT(inode_listxattr, selinux_inode_listxattr), + LSM_HOOK_INIT(inode_removexattr, selinux_inode_removexattr), + LSM_HOOK_INIT(inode_file_getattr, selinux_inode_file_getattr), + LSM_HOOK_INIT(inode_file_setattr, selinux_inode_file_setattr), + LSM_HOOK_INIT(inode_set_acl, selinux_inode_set_acl), + LSM_HOOK_INIT(inode_get_acl, selinux_inode_get_acl), + LSM_HOOK_INIT(inode_remove_acl, selinux_inode_remove_acl), + LSM_HOOK_INIT(inode_getsecurity, selinux_inode_getsecurity), + LSM_HOOK_INIT(inode_setsecurity, selinux_inode_setsecurity), + LSM_HOOK_INIT(inode_listsecurity, selinux_inode_listsecurity), + LSM_HOOK_INIT(inode_getlsmprop, selinux_inode_getlsmprop), + LSM_HOOK_INIT(inode_copy_up, selinux_inode_copy_up), + LSM_HOOK_INIT(inode_copy_up_xattr, selinux_inode_copy_up_xattr), + LSM_HOOK_INIT(path_notify, selinux_path_notify), + + LSM_HOOK_INIT(kernfs_init_security, selinux_kernfs_init_security), + + LSM_HOOK_INIT(file_permission, selinux_file_permission), + LSM_HOOK_INIT(file_alloc_security, selinux_file_alloc_security), + LSM_HOOK_INIT(backing_file_alloc, selinux_backing_file_alloc), + LSM_HOOK_INIT(file_ioctl, selinux_file_ioctl), + LSM_HOOK_INIT(file_ioctl_compat, selinux_file_ioctl_compat), + LSM_HOOK_INIT(mmap_file, selinux_mmap_file), + LSM_HOOK_INIT(mmap_backing_file, selinux_mmap_backing_file), + LSM_HOOK_INIT(mmap_addr, selinux_mmap_addr), + LSM_HOOK_INIT(file_mprotect, selinux_file_mprotect), + LSM_HOOK_INIT(file_lock, selinux_file_lock), + LSM_HOOK_INIT(file_fcntl, selinux_file_fcntl), + LSM_HOOK_INIT(file_set_fowner, selinux_file_set_fowner), + LSM_HOOK_INIT(file_send_sigiotask, selinux_file_send_sigiotask), + LSM_HOOK_INIT(file_receive, selinux_file_receive), + + LSM_HOOK_INIT(file_open, selinux_file_open), + + LSM_HOOK_INIT(task_alloc, selinux_task_alloc), + LSM_HOOK_INIT(cred_prepare, selinux_cred_prepare), + LSM_HOOK_INIT(cred_transfer, selinux_cred_transfer), + LSM_HOOK_INIT(cred_getsecid, selinux_cred_getsecid), + LSM_HOOK_INIT(cred_getlsmprop, selinux_cred_getlsmprop), + LSM_HOOK_INIT(kernel_act_as, selinux_kernel_act_as), + LSM_HOOK_INIT(kernel_create_files_as, selinux_kernel_create_files_as), + LSM_HOOK_INIT(kernel_module_request, selinux_kernel_module_request), + LSM_HOOK_INIT(kernel_load_data, selinux_kernel_load_data), + LSM_HOOK_INIT(kernel_read_file, selinux_kernel_read_file), + LSM_HOOK_INIT(task_setpgid, selinux_task_setpgid), + LSM_HOOK_INIT(task_getpgid, selinux_task_getpgid), + LSM_HOOK_INIT(task_getsid, selinux_task_getsid), + LSM_HOOK_INIT(current_getlsmprop_subj, selinux_current_getlsmprop_subj), + LSM_HOOK_INIT(task_getlsmprop_obj, selinux_task_getlsmprop_obj), + LSM_HOOK_INIT(task_setnice, selinux_task_setnice), + LSM_HOOK_INIT(task_setioprio, selinux_task_setioprio), + LSM_HOOK_INIT(task_getioprio, selinux_task_getioprio), + LSM_HOOK_INIT(task_prlimit, selinux_task_prlimit), + LSM_HOOK_INIT(task_setrlimit, selinux_task_setrlimit), + LSM_HOOK_INIT(task_setscheduler, selinux_task_setscheduler), + LSM_HOOK_INIT(task_getscheduler, selinux_task_getscheduler), + LSM_HOOK_INIT(task_movememory, selinux_task_movememory), + LSM_HOOK_INIT(task_kill, selinux_task_kill), + LSM_HOOK_INIT(task_to_inode, selinux_task_to_inode), + LSM_HOOK_INIT(userns_create, selinux_userns_create), + + LSM_HOOK_INIT(ipc_permission, selinux_ipc_permission), + LSM_HOOK_INIT(ipc_getlsmprop, selinux_ipc_getlsmprop), + + LSM_HOOK_INIT(msg_queue_associate, selinux_msg_queue_associate), + LSM_HOOK_INIT(msg_queue_msgctl, selinux_msg_queue_msgctl), + LSM_HOOK_INIT(msg_queue_msgsnd, selinux_msg_queue_msgsnd), + LSM_HOOK_INIT(msg_queue_msgrcv, selinux_msg_queue_msgrcv), + + LSM_HOOK_INIT(shm_associate, selinux_shm_associate), + LSM_HOOK_INIT(shm_shmctl, selinux_shm_shmctl), + LSM_HOOK_INIT(shm_shmat, selinux_shm_shmat), + + LSM_HOOK_INIT(sem_associate, selinux_sem_associate), + LSM_HOOK_INIT(sem_semctl, selinux_sem_semctl), + LSM_HOOK_INIT(sem_semop, selinux_sem_semop), + + LSM_HOOK_INIT(d_instantiate, selinux_d_instantiate), + + LSM_HOOK_INIT(getselfattr, selinux_getselfattr), + LSM_HOOK_INIT(setselfattr, selinux_setselfattr), + LSM_HOOK_INIT(getprocattr, selinux_getprocattr), + LSM_HOOK_INIT(setprocattr, selinux_setprocattr), + + LSM_HOOK_INIT(ismaclabel, selinux_ismaclabel), + LSM_HOOK_INIT(secctx_to_secid, selinux_secctx_to_secid), + LSM_HOOK_INIT(release_secctx, selinux_release_secctx), + LSM_HOOK_INIT(inode_invalidate_secctx, selinux_inode_invalidate_secctx), + LSM_HOOK_INIT(inode_notifysecctx, selinux_inode_notifysecctx), + LSM_HOOK_INIT(inode_setsecctx, selinux_inode_setsecctx), + + LSM_HOOK_INIT(unix_stream_connect, selinux_socket_unix_stream_connect), + LSM_HOOK_INIT(unix_may_send, selinux_socket_unix_may_send), + + LSM_HOOK_INIT(socket_create, selinux_socket_create), + LSM_HOOK_INIT(socket_post_create, selinux_socket_post_create), + LSM_HOOK_INIT(socket_socketpair, selinux_socket_socketpair), + LSM_HOOK_INIT(socket_bind, selinux_socket_bind), + LSM_HOOK_INIT(socket_connect, selinux_socket_connect), + LSM_HOOK_INIT(socket_listen, selinux_socket_listen), + LSM_HOOK_INIT(socket_accept, selinux_socket_accept), + LSM_HOOK_INIT(socket_sendmsg, selinux_socket_sendmsg), + LSM_HOOK_INIT(socket_recvmsg, selinux_socket_recvmsg), + LSM_HOOK_INIT(socket_getsockname, selinux_socket_getsockname), + LSM_HOOK_INIT(socket_getpeername, selinux_socket_getpeername), + LSM_HOOK_INIT(socket_getsockopt, selinux_socket_getsockopt), + LSM_HOOK_INIT(socket_setsockopt, selinux_socket_setsockopt), + LSM_HOOK_INIT(socket_shutdown, selinux_socket_shutdown), + LSM_HOOK_INIT(socket_sock_rcv_skb, selinux_socket_sock_rcv_skb), + LSM_HOOK_INIT(socket_getpeersec_stream, + selinux_socket_getpeersec_stream), + LSM_HOOK_INIT(socket_getpeersec_dgram, selinux_socket_getpeersec_dgram), + LSM_HOOK_INIT(sk_free_security, selinux_sk_free_security), + LSM_HOOK_INIT(sk_clone_security, selinux_sk_clone_security), + LSM_HOOK_INIT(sk_getsecid, selinux_sk_getsecid), + LSM_HOOK_INIT(sock_graft, selinux_sock_graft), + LSM_HOOK_INIT(sctp_assoc_request, selinux_sctp_assoc_request), + LSM_HOOK_INIT(sctp_sk_clone, selinux_sctp_sk_clone), + LSM_HOOK_INIT(sctp_bind_connect, selinux_sctp_bind_connect), + LSM_HOOK_INIT(sctp_assoc_established, selinux_sctp_assoc_established), + LSM_HOOK_INIT(mptcp_add_subflow, selinux_mptcp_add_subflow), + LSM_HOOK_INIT(inet_conn_request, selinux_inet_conn_request), + LSM_HOOK_INIT(inet_csk_clone, selinux_inet_csk_clone), + LSM_HOOK_INIT(inet_conn_established, selinux_inet_conn_established), + LSM_HOOK_INIT(secmark_relabel_packet, selinux_secmark_relabel_packet), + LSM_HOOK_INIT(secmark_refcount_inc, selinux_secmark_refcount_inc), + LSM_HOOK_INIT(secmark_refcount_dec, selinux_secmark_refcount_dec), + LSM_HOOK_INIT(req_classify_flow, selinux_req_classify_flow), + LSM_HOOK_INIT(tun_dev_create, selinux_tun_dev_create), + LSM_HOOK_INIT(tun_dev_attach_queue, selinux_tun_dev_attach_queue), + LSM_HOOK_INIT(tun_dev_attach, selinux_tun_dev_attach), + LSM_HOOK_INIT(tun_dev_open, selinux_tun_dev_open), +#ifdef CONFIG_SECURITY_INFINIBAND + LSM_HOOK_INIT(ib_pkey_access, selinux_ib_pkey_access), + LSM_HOOK_INIT(ib_endport_manage_subnet, + selinux_ib_endport_manage_subnet), +#endif +#ifdef CONFIG_SECURITY_NETWORK_XFRM + LSM_HOOK_INIT(xfrm_policy_free_security, selinux_xfrm_policy_free), + LSM_HOOK_INIT(xfrm_policy_delete_security, selinux_xfrm_policy_delete), + LSM_HOOK_INIT(xfrm_state_free_security, selinux_xfrm_state_free), + LSM_HOOK_INIT(xfrm_state_delete_security, selinux_xfrm_state_delete), + LSM_HOOK_INIT(xfrm_policy_lookup, selinux_xfrm_policy_lookup), + LSM_HOOK_INIT(xfrm_state_pol_flow_match, + selinux_xfrm_state_pol_flow_match), + LSM_HOOK_INIT(xfrm_decode_session, selinux_xfrm_decode_session), +#endif + +#ifdef CONFIG_KEYS + LSM_HOOK_INIT(key_permission, selinux_key_permission), + LSM_HOOK_INIT(key_getsecurity, selinux_key_getsecurity), +#ifdef CONFIG_KEY_NOTIFICATIONS + LSM_HOOK_INIT(watch_key, selinux_watch_key), +#endif +#endif + +#ifdef CONFIG_AUDIT + LSM_HOOK_INIT(audit_rule_known, selinux_audit_rule_known), + LSM_HOOK_INIT(audit_rule_match, selinux_audit_rule_match), + LSM_HOOK_INIT(audit_rule_free, selinux_audit_rule_free), +#endif + +#ifdef CONFIG_BPF_SYSCALL + LSM_HOOK_INIT(bpf, selinux_bpf), + LSM_HOOK_INIT(bpf_map, selinux_bpf_map), + LSM_HOOK_INIT(bpf_prog, selinux_bpf_prog), +#endif + +#ifdef CONFIG_PERF_EVENTS + LSM_HOOK_INIT(perf_event_open, selinux_perf_event_open), + LSM_HOOK_INIT(perf_event_read, selinux_perf_event_read), + LSM_HOOK_INIT(perf_event_write, selinux_perf_event_write), +#endif + +#ifdef CONFIG_IO_URING + LSM_HOOK_INIT(uring_override_creds, selinux_uring_override_creds), + LSM_HOOK_INIT(uring_sqpoll, selinux_uring_sqpoll), + LSM_HOOK_INIT(uring_cmd, selinux_uring_cmd), + LSM_HOOK_INIT(uring_allowed, selinux_uring_allowed), +#endif + + /* + * PUT "CLONING" (ACCESSING + ALLOCATING) HOOKS HERE + */ + LSM_HOOK_INIT(fs_context_submount, selinux_fs_context_submount), + LSM_HOOK_INIT(fs_context_dup, selinux_fs_context_dup), + LSM_HOOK_INIT(fs_context_parse_param, selinux_fs_context_parse_param), + LSM_HOOK_INIT(sb_eat_lsm_opts, selinux_sb_eat_lsm_opts), +#ifdef CONFIG_SECURITY_NETWORK_XFRM + LSM_HOOK_INIT(xfrm_policy_clone_security, selinux_xfrm_policy_clone), +#endif + + /* + * PUT "ALLOCATING" HOOKS HERE + */ + LSM_HOOK_INIT(msg_msg_alloc_security, selinux_msg_msg_alloc_security), + LSM_HOOK_INIT(msg_queue_alloc_security, + selinux_msg_queue_alloc_security), + LSM_HOOK_INIT(shm_alloc_security, selinux_shm_alloc_security), + LSM_HOOK_INIT(sb_alloc_security, selinux_sb_alloc_security), + LSM_HOOK_INIT(inode_alloc_security, selinux_inode_alloc_security), + LSM_HOOK_INIT(sem_alloc_security, selinux_sem_alloc_security), + LSM_HOOK_INIT(secid_to_secctx, selinux_secid_to_secctx), + LSM_HOOK_INIT(lsmprop_to_secctx, selinux_lsmprop_to_secctx), + LSM_HOOK_INIT(inode_getsecctx, selinux_inode_getsecctx), + LSM_HOOK_INIT(sk_alloc_security, selinux_sk_alloc_security), + LSM_HOOK_INIT(tun_dev_alloc_security, selinux_tun_dev_alloc_security), +#ifdef CONFIG_SECURITY_INFINIBAND + LSM_HOOK_INIT(ib_alloc_security, selinux_ib_alloc_security), +#endif +#ifdef CONFIG_SECURITY_NETWORK_XFRM + LSM_HOOK_INIT(xfrm_policy_alloc_security, selinux_xfrm_policy_alloc), + LSM_HOOK_INIT(xfrm_state_alloc, selinux_xfrm_state_alloc), + LSM_HOOK_INIT(xfrm_state_alloc_acquire, + selinux_xfrm_state_alloc_acquire), +#endif +#ifdef CONFIG_KEYS + LSM_HOOK_INIT(key_alloc, selinux_key_alloc), +#endif +#ifdef CONFIG_AUDIT + LSM_HOOK_INIT(audit_rule_init, selinux_audit_rule_init), +#endif +#ifdef CONFIG_BPF_SYSCALL + LSM_HOOK_INIT(bpf_map_create, selinux_bpf_map_create), + LSM_HOOK_INIT(bpf_prog_load, selinux_bpf_prog_load), + LSM_HOOK_INIT(bpf_token_create, selinux_bpf_token_create), + LSM_HOOK_INIT(bpf_token_cmd, selinux_bpf_token_cmd), + LSM_HOOK_INIT(bpf_token_capable, selinux_bpf_token_capable), +#endif +#ifdef CONFIG_PERF_EVENTS + LSM_HOOK_INIT(perf_event_alloc, selinux_perf_event_alloc), +#endif +}; + +static __init int selinux_init(void) +{ + vma_flags_t data_default_flags = VMA_DATA_DEFAULT_FLAGS; + + pr_info("SELinux: Initializing.\n"); + + memset(&selinux_state, 0, sizeof(selinux_state)); + enforcing_set(selinux_enforcing_boot); + selinux_avc_init(); + mutex_init(&selinux_state.status_lock); + mutex_init(&selinux_state.policy_mutex); + + /* Set the security state for the initial task. */ + cred_init_security(); + + /* Inform the audit system that secctx is used */ + audit_cfg_lsm(&selinux_lsmid, + AUDIT_CFG_LSM_SECCTX_SUBJECT | + AUDIT_CFG_LSM_SECCTX_OBJECT); + + default_noexec = !vma_flags_test(&data_default_flags, VMA_EXEC_BIT); + if (!default_noexec) + pr_notice("SELinux: virtual memory is executable by default\n"); + + avc_init(); + + avtab_cache_init(); + + ebitmap_cache_init(); + + hashtab_cache_init(); + + selinux_ima_config_len_init(); + + security_add_hooks(selinux_hooks, ARRAY_SIZE(selinux_hooks), + &selinux_lsmid); + + if (avc_add_callback(selinux_netcache_avc_callback, AVC_CALLBACK_RESET)) + panic("SELinux: Unable to register AVC netcache callback\n"); + + if (avc_add_callback(selinux_lsm_notifier_avc_callback, AVC_CALLBACK_RESET)) + panic("SELinux: Unable to register AVC LSM notifier callback\n"); + + if (avc_add_callback(selinux_audit_rule_avc_callback, + AVC_CALLBACK_RESET)) + panic("SELinux: Unable to register AVC audit callback\n"); + + if (selinux_enforcing_boot) + pr_debug("SELinux: Starting in enforcing mode\n"); + else + pr_debug("SELinux: Starting in permissive mode\n"); + + fs_validate_description("selinux", selinux_fs_parameters); + + return 0; +} + +static void delayed_superblock_init(struct super_block *sb, void *unused) +{ + selinux_set_mnt_opts(sb, NULL, 0, NULL); +} + +void selinux_complete_init(void) +{ + pr_debug("SELinux: Completing initialization.\n"); + + /* Set up any superblocks initialized prior to the policy load. */ + pr_debug("SELinux: Setting up existing superblocks.\n"); + iterate_supers(delayed_superblock_init, NULL); +} + +/* SELinux requires early initialization in order to label + all processes and objects when they are created. */ +DEFINE_LSM(selinux) = { + .id = &selinux_lsmid, + .flags = LSM_FLAG_LEGACY_MAJOR | LSM_FLAG_EXCLUSIVE, + .enabled = &selinux_enabled_boot, + .blobs = &selinux_blob_sizes, + .init = selinux_init, + .initcall_device = selinux_initcall, +}; + +#if defined(CONFIG_NETFILTER) +static const struct nf_hook_ops selinux_nf_ops[] = { + { + .hook = selinux_ip_postroute, + .pf = NFPROTO_IPV4, + .hooknum = NF_INET_POST_ROUTING, + .priority = NF_IP_PRI_SELINUX_LAST, + }, + { + .hook = selinux_ip_forward, + .pf = NFPROTO_IPV4, + .hooknum = NF_INET_FORWARD, + .priority = NF_IP_PRI_SELINUX_FIRST, + }, + { + .hook = selinux_ip_output, + .pf = NFPROTO_IPV4, + .hooknum = NF_INET_LOCAL_OUT, + .priority = NF_IP_PRI_SELINUX_FIRST, + }, +#if IS_ENABLED(CONFIG_IPV6) + { + .hook = selinux_ip_postroute, + .pf = NFPROTO_IPV6, + .hooknum = NF_INET_POST_ROUTING, + .priority = NF_IP6_PRI_SELINUX_LAST, + }, + { + .hook = selinux_ip_forward, + .pf = NFPROTO_IPV6, + .hooknum = NF_INET_FORWARD, + .priority = NF_IP6_PRI_SELINUX_FIRST, + }, + { + .hook = selinux_ip_output, + .pf = NFPROTO_IPV6, + .hooknum = NF_INET_LOCAL_OUT, + .priority = NF_IP6_PRI_SELINUX_FIRST, + }, +#endif /* IPV6 */ +}; + +static int __net_init selinux_nf_register(struct net *net) +{ + return nf_register_net_hooks(net, selinux_nf_ops, + ARRAY_SIZE(selinux_nf_ops)); +} + +static void __net_exit selinux_nf_unregister(struct net *net) +{ + nf_unregister_net_hooks(net, selinux_nf_ops, + ARRAY_SIZE(selinux_nf_ops)); +} + +static struct pernet_operations selinux_net_ops = { + .init = selinux_nf_register, + .exit = selinux_nf_unregister, +}; + +int __init selinux_nf_ip_init(void) +{ + int err; + + if (!selinux_enabled_boot) + return 0; + + pr_debug("SELinux: Registering netfilter hooks\n"); + + err = register_pernet_subsys(&selinux_net_ops); + if (err) + panic("SELinux: register_pernet_subsys: error %d\n", err); + + return 0; +} +#endif /* CONFIG_NETFILTER */ diff --git a/security/selinux/ibpkey.c b/security/selinux/ibpkey.c new file mode 100644 index 000000000..ae09d59aa --- /dev/null +++ b/security/selinux/ibpkey.c @@ -0,0 +1,235 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Pkey table + * + * SELinux must keep a mapping of Infiniband PKEYs to labels/SIDs. This + * mapping is maintained as part of the normal policy but a fast cache is + * needed to reduce the lookup overhead. + * + * This code is heavily based on the "netif" and "netport" concept originally + * developed by + * James Morris <jmorris@redhat.com> and + * Paul Moore <paul@paul-moore.com> + * (see security/selinux/netif.c and security/selinux/netport.c for more + * information) + */ + +/* + * (c) Mellanox Technologies, 2016 + */ + +#include <linux/types.h> +#include <linux/rcupdate.h> +#include <linux/list.h> +#include <linux/spinlock.h> + +#include "initcalls.h" +#include "ibpkey.h" +#include "objsec.h" + +#define SEL_PKEY_HASH_SIZE 256 +#define SEL_PKEY_HASH_BKT_LIMIT 16 + +struct sel_ib_pkey_bkt { + int size; + struct list_head list; +}; + +struct sel_ib_pkey { + struct pkey_security_struct psec; + struct list_head list; + struct rcu_head rcu; +}; + +static DEFINE_SPINLOCK(sel_ib_pkey_lock); +static struct sel_ib_pkey_bkt sel_ib_pkey_hash[SEL_PKEY_HASH_SIZE]; + +/** + * sel_ib_pkey_hashfn - Hashing function for the pkey table + * @pkey: pkey number + * + * Description: + * This is the hashing function for the pkey table, it returns the bucket + * number for the given pkey. + * + */ +static unsigned int sel_ib_pkey_hashfn(u16 pkey) +{ + return (pkey & (SEL_PKEY_HASH_SIZE - 1)); +} + +/** + * sel_ib_pkey_find - Search for a pkey record + * @subnet_prefix: subnet_prefix + * @pkey_num: pkey_num + * + * Description: + * Search the pkey table and return the matching record. If an entry + * can not be found in the table return NULL. + * + */ +static struct sel_ib_pkey *sel_ib_pkey_find(u64 subnet_prefix, u16 pkey_num) +{ + unsigned int idx; + struct sel_ib_pkey *pkey; + + idx = sel_ib_pkey_hashfn(pkey_num); + list_for_each_entry_rcu(pkey, &sel_ib_pkey_hash[idx].list, list) { + if (pkey->psec.pkey == pkey_num && + pkey->psec.subnet_prefix == subnet_prefix) + return pkey; + } + + return NULL; +} + +/** + * sel_ib_pkey_insert - Insert a new pkey into the table + * @pkey: the new pkey record + * + * Description: + * Add a new pkey record to the hash table. + * + */ +static void sel_ib_pkey_insert(struct sel_ib_pkey *pkey) +{ + unsigned int idx; + + /* we need to impose a limit on the growth of the hash table so check + * this bucket to make sure it is within the specified bounds + */ + idx = sel_ib_pkey_hashfn(pkey->psec.pkey); + list_add_rcu(&pkey->list, &sel_ib_pkey_hash[idx].list); + if (sel_ib_pkey_hash[idx].size == SEL_PKEY_HASH_BKT_LIMIT) { + struct sel_ib_pkey *tail; + + tail = list_entry( + rcu_dereference_protected( + list_tail_rcu(&sel_ib_pkey_hash[idx].list), + lockdep_is_held(&sel_ib_pkey_lock)), + struct sel_ib_pkey, list); + list_del_rcu(&tail->list); + kfree_rcu(tail, rcu); + } else { + sel_ib_pkey_hash[idx].size++; + } +} + +/** + * sel_ib_pkey_sid_slow - Lookup the SID of a pkey using the policy + * @subnet_prefix: subnet prefix + * @pkey_num: pkey number + * @sid: pkey SID + * + * Description: + * This function determines the SID of a pkey by querying the security + * policy. The result is added to the pkey table to speedup future + * queries. Returns zero on success, negative values on failure. + * + */ +static int sel_ib_pkey_sid_slow(u64 subnet_prefix, u16 pkey_num, u32 *sid) +{ + int ret; + struct sel_ib_pkey *pkey; + struct sel_ib_pkey *new; + unsigned long flags; + + spin_lock_irqsave(&sel_ib_pkey_lock, flags); + pkey = sel_ib_pkey_find(subnet_prefix, pkey_num); + if (pkey) { + *sid = pkey->psec.sid; + spin_unlock_irqrestore(&sel_ib_pkey_lock, flags); + return 0; + } + + ret = security_ib_pkey_sid(subnet_prefix, pkey_num, + sid); + if (ret) + goto out; + + new = kmalloc_obj(*new, GFP_ATOMIC); + if (!new) { + /* If this memory allocation fails still return 0. The SID + * is valid, it just won't be added to the cache. + */ + goto out; + } + + new->psec.subnet_prefix = subnet_prefix; + new->psec.pkey = pkey_num; + new->psec.sid = *sid; + sel_ib_pkey_insert(new); + +out: + spin_unlock_irqrestore(&sel_ib_pkey_lock, flags); + return ret; +} + +/** + * sel_ib_pkey_sid - Lookup the SID of a PKEY + * @subnet_prefix: subnet_prefix + * @pkey_num: pkey number + * @sid: pkey SID + * + * Description: + * This function determines the SID of a PKEY using the fastest method + * possible. First the pkey table is queried, but if an entry can't be found + * then the policy is queried and the result is added to the table to speedup + * future queries. Returns zero on success, negative values on failure. + * + */ +int sel_ib_pkey_sid(u64 subnet_prefix, u16 pkey_num, u32 *sid) +{ + struct sel_ib_pkey *pkey; + + rcu_read_lock(); + pkey = sel_ib_pkey_find(subnet_prefix, pkey_num); + if (likely(pkey)) { + *sid = pkey->psec.sid; + rcu_read_unlock(); + return 0; + } + rcu_read_unlock(); + + return sel_ib_pkey_sid_slow(subnet_prefix, pkey_num, sid); +} + +/** + * sel_ib_pkey_flush - Flush the entire pkey table + * + * Description: + * Remove all entries from the pkey table + * + */ +void sel_ib_pkey_flush(void) +{ + unsigned int idx; + struct sel_ib_pkey *pkey, *pkey_tmp; + unsigned long flags; + + spin_lock_irqsave(&sel_ib_pkey_lock, flags); + for (idx = 0; idx < SEL_PKEY_HASH_SIZE; idx++) { + list_for_each_entry_safe(pkey, pkey_tmp, + &sel_ib_pkey_hash[idx].list, list) { + list_del_rcu(&pkey->list); + kfree_rcu(pkey, rcu); + } + sel_ib_pkey_hash[idx].size = 0; + } + spin_unlock_irqrestore(&sel_ib_pkey_lock, flags); +} + +int __init sel_ib_pkey_init(void) +{ + int iter; + + if (!selinux_enabled_boot) + return 0; + + for (iter = 0; iter < SEL_PKEY_HASH_SIZE; iter++) { + INIT_LIST_HEAD(&sel_ib_pkey_hash[iter].list); + sel_ib_pkey_hash[iter].size = 0; + } + + return 0; +} diff --git a/security/selinux/ima.c b/security/selinux/ima.c new file mode 100644 index 000000000..cda68122e --- /dev/null +++ b/security/selinux/ima.c @@ -0,0 +1,121 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (C) 2021 Microsoft Corporation + * + * Author: Lakshmi Ramasubramanian (nramas@linux.microsoft.com) + * + * Measure critical data structures maintained by SELinux + * using IMA subsystem. + */ +#include <linux/vmalloc.h> +#include <linux/ima.h> +#include <linux/seq_buf.h> +#include "security.h" +#include "ima.h" + +static int selinux_ima_config_len __ro_after_init; + +/* + * selinux_ima_config_len_init - Compute the configuration settings string length + * + * The string is fixed text plus one digit per setting, so its length + * is known at boot. + */ +void __init selinux_ima_config_len_init(void) +{ + int buf_len, suffix_len, i; + + buf_len = strlen("initialized=0;enforcing=0;checkreqprot=0;") + 1; + suffix_len = strlen("=0;"); + + for (i = 0; i < __POLICYDB_CAP_MAX; i++) + buf_len += strlen(selinux_policycap_names[i]) + suffix_len; + + selinux_ima_config_len = buf_len; +} + +/* + * selinux_ima_collect_state - Read selinux configuration settings + * + * On success returns the configuration settings string. + * On error, returns NULL. + */ +static char *selinux_ima_collect_state(void) +{ + struct seq_buf s; + char *buf; + int i; + + buf = kzalloc(selinux_ima_config_len, GFP_KERNEL); + if (!buf) + return NULL; + + seq_buf_init(&s, buf, selinux_ima_config_len); + + seq_buf_printf(&s, "initialized=%d;enforcing=%d;checkreqprot=%d;", + selinux_initialized(), enforcing_enabled(), + checkreqprot_get()); + + for (i = 0; i < __POLICYDB_CAP_MAX; i++) + seq_buf_printf(&s, "%s=%d;", selinux_policycap_names[i], + selinux_state.policycap[i]); + + WARN_ON(seq_buf_has_overflowed(&s)); + + return buf; +} + +/* + * selinux_ima_measure_state_locked - Measure SELinux state and hash of policy + */ +void selinux_ima_measure_state_locked(void) +{ + char *state_str = NULL; + void *policy = NULL; + size_t policy_len; + int rc = 0; + + lockdep_assert_held(&selinux_state.policy_mutex); + + state_str = selinux_ima_collect_state(); + if (!state_str) { + pr_err("SELinux: %s: failed to read state.\n", __func__); + return; + } + + ima_measure_critical_data("selinux", "selinux-state", + state_str, strlen(state_str), false, + NULL, 0); + + kfree(state_str); + + /* + * Measure SELinux policy only after initialization is completed. + */ + if (!selinux_initialized()) + return; + + rc = security_read_state_kernel(&policy, &policy_len); + if (rc) { + pr_err("SELinux: %s: failed to read policy %d.\n", __func__, rc); + return; + } + + ima_measure_critical_data("selinux", "selinux-policy-hash", + policy, policy_len, true, + NULL, 0); + + vfree(policy); +} + +/* + * selinux_ima_measure_state - Measure SELinux state and hash of policy + */ +void selinux_ima_measure_state(void) +{ + lockdep_assert_not_held(&selinux_state.policy_mutex); + + mutex_lock(&selinux_state.policy_mutex); + selinux_ima_measure_state_locked(); + mutex_unlock(&selinux_state.policy_mutex); +} diff --git a/security/selinux/include/audit.h b/security/selinux/include/audit.h new file mode 100644 index 000000000..85a531ac7 --- /dev/null +++ b/security/selinux/include/audit.h @@ -0,0 +1,71 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * SELinux support for the Audit LSM hooks + * + * Author: James Morris <jmorris@redhat.com> + * + * Copyright (C) 2005 Red Hat, Inc., James Morris <jmorris@redhat.com> + * Copyright (C) 2006 Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com> + * Copyright (C) 2006 IBM Corporation, Timothy R. Chavez <tinytim@us.ibm.com> + */ + +#ifndef _SELINUX_AUDIT_H +#define _SELINUX_AUDIT_H + +#include <linux/audit.h> +#include <linux/types.h> + +/** + * selinux_audit_rule_avc_callback - update the audit LSM rules on AVC events. + * @event: the AVC event + * + * Update any audit LSM rules based on the AVC event specified in @event. + * Returns 0 on success, negative values otherwise. + */ +int selinux_audit_rule_avc_callback(u32 event); + +/** + * selinux_audit_rule_init - alloc/init an selinux audit rule structure. + * @field: the field this rule refers to + * @op: the operator the rule uses + * @rulestr: the text "target" of the rule + * @rule: pointer to the new rule structure returned via this + * @gfp: GFP flag used for kmalloc + * + * Returns 0 if successful, -errno if not. On success, the rule structure + * will be allocated internally. The caller must free this structure with + * selinux_audit_rule_free() after use. + */ +int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **rule, + gfp_t gfp); + +/** + * selinux_audit_rule_free - free an selinux audit rule structure. + * @rule: pointer to the audit rule to be freed + * + * This will free all memory associated with the given rule. + * If @rule is NULL, no operation is performed. + */ +void selinux_audit_rule_free(void *rule); + +/** + * selinux_audit_rule_match - determine if a context ID matches a rule. + * @prop: includes the context ID to check + * @field: the field this rule refers to + * @op: the operator the rule uses + * @rule: pointer to the audit rule to check against + * + * Returns 1 if the context id matches the rule, 0 if it does not, and + * -errno on failure. + */ +int selinux_audit_rule_match(struct lsm_prop *prop, u32 field, u32 op, + void *rule); + +/** + * selinux_audit_rule_known - check to see if rule contains selinux fields. + * @rule: rule to be checked + * Returns 1 if there are selinux fields specified in the rule, 0 otherwise. + */ +int selinux_audit_rule_known(struct audit_krule *rule); + +#endif /* _SELINUX_AUDIT_H */ diff --git a/security/selinux/include/avc.h b/security/selinux/include/avc.h new file mode 100644 index 000000000..01b5167fe --- /dev/null +++ b/security/selinux/include/avc.h @@ -0,0 +1,172 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Access vector cache interface for object managers. + * + * Author : Stephen Smalley, <stephen.smalley.work@gmail.com> + */ + +#ifndef _SELINUX_AVC_H_ +#define _SELINUX_AVC_H_ + +#include <linux/stddef.h> +#include <linux/errno.h> +#include <linux/kernel.h> +#include <linux/kdev_t.h> +#include <linux/spinlock.h> +#include <linux/init.h> +#include <linux/audit.h> +#include <linux/lsm_audit.h> +#include <linux/in6.h> +#include "flask.h" +#include "av_permissions.h" +#include "security.h" + +/* + * An entry in the AVC. + */ +struct avc_entry; + +struct task_struct; +struct inode; +struct sock; +struct sk_buff; + +/* + * AVC statistics + */ +struct avc_cache_stats { + unsigned int lookups; + unsigned int misses; + unsigned int allocations; + unsigned int reclaims; + unsigned int frees; +}; + +/* + * We only need this data after we have decided to send an audit message. + */ +struct selinux_audit_data { + u32 ssid; + u32 tsid; + u16 tclass; + u32 requested; + u32 audited; + u32 denied; + int result; +} __randomize_layout; + +/* + * AVC operations + */ + +void __init avc_init(void); + +static inline u32 avc_audit_required(u32 requested, struct av_decision *avd, + int result, u32 auditdeny, u32 *deniedp) +{ + u32 denied, audited; + + if (avd->flags & AVD_FLAGS_NEVERAUDIT) + return 0; + + denied = requested & ~avd->allowed; + if (unlikely(denied)) { + audited = denied & avd->auditdeny; + /* + * auditdeny is TRICKY! Setting a bit in + * this field means that ANY denials should NOT be audited if + * the policy contains an explicit dontaudit rule for that + * permission. Take notice that this is unrelated to the + * actual permissions that were denied. As an example lets + * assume: + * + * denied == READ + * avd.auditdeny & ACCESS == 0 (not set means explicit rule) + * auditdeny & ACCESS == 1 + * + * We will NOT audit the denial even though the denied + * permission was READ and the auditdeny checks were for + * ACCESS + */ + if (auditdeny && !(auditdeny & avd->auditdeny)) + audited = 0; + } else if (result) + audited = denied = requested; + else + audited = requested & avd->auditallow; + *deniedp = denied; + return audited; +} + +int slow_avc_audit(u32 ssid, u32 tsid, u16 tclass, u32 requested, u32 audited, + u32 denied, int result, struct common_audit_data *a); + +/** + * avc_audit - Audit the granting or denial of permissions. + * @ssid: source security identifier + * @tsid: target security identifier + * @tclass: target security class + * @requested: requested permissions + * @avd: access vector decisions + * @result: result from avc_has_perm_noaudit + * @a: auxiliary audit data + * + * Audit the granting or denial of permissions in accordance + * with the policy. This function is typically called by + * avc_has_perm() after a permission check, but can also be + * called directly by callers who use avc_has_perm_noaudit() + * in order to separate the permission check from the auditing. + * For example, this separation is useful when the permission check must + * be performed under a lock, to allow the lock to be released + * before calling the auditing code. + */ +static inline int avc_audit(u32 ssid, u32 tsid, u16 tclass, u32 requested, + struct av_decision *avd, int result, + struct common_audit_data *a) +{ + u32 audited, denied; + audited = avc_audit_required(requested, avd, result, 0, &denied); + if (likely(!audited)) + return 0; + return slow_avc_audit(ssid, tsid, tclass, requested, audited, denied, + result, a); +} + +#define AVC_STRICT 1 /* Ignore permissive mode. */ +#define AVC_EXTENDED_PERMS 2 /* update extended permissions */ +int avc_has_perm_noaudit(u32 ssid, u32 tsid, u16 tclass, u32 requested, + unsigned int flags, struct av_decision *avd); + +int avc_has_perm(u32 ssid, u32 tsid, u16 tclass, u32 requested, + struct common_audit_data *auditdata); + +#define AVC_EXT_IOCTL (1 << 0) /* Cache entry for an ioctl extended permission */ +#define AVC_EXT_NLMSG (1 << 1) /* Cache entry for an nlmsg extended permission */ +int avc_has_extended_perms(u32 ssid, u32 tsid, u16 tclass, u32 requested, + u8 driver, u8 base_perm, u8 perm, + struct common_audit_data *ad); + +u32 avc_policy_seqno(void); + +#define AVC_CALLBACK_GRANT 1 +#define AVC_CALLBACK_TRY_REVOKE 2 +#define AVC_CALLBACK_REVOKE 4 +#define AVC_CALLBACK_RESET 8 +#define AVC_CALLBACK_AUDITALLOW_ENABLE 16 +#define AVC_CALLBACK_AUDITALLOW_DISABLE 32 +#define AVC_CALLBACK_AUDITDENY_ENABLE 64 +#define AVC_CALLBACK_AUDITDENY_DISABLE 128 +#define AVC_CALLBACK_ADD_XPERMS 256 + +int avc_add_callback(int (*callback)(u32 event), u32 events); + +/* Exported to selinuxfs */ +int avc_get_hash_stats(char *page); +unsigned int avc_get_cache_threshold(void); +void avc_set_cache_threshold(unsigned int cache_threshold); + +#ifdef CONFIG_SECURITY_SELINUX_AVC_STATS +DECLARE_PER_CPU(struct avc_cache_stats, avc_cache_stats); +#endif + +#endif /* _SELINUX_AVC_H_ */ diff --git a/security/selinux/include/avc_ss.h b/security/selinux/include/avc_ss.h new file mode 100644 index 000000000..48ad64d54 --- /dev/null +++ b/security/selinux/include/avc_ss.h @@ -0,0 +1,23 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Access vector cache interface for the security server. + * + * Author : Stephen Smalley, <stephen.smalley.work@gmail.com> + */ + +#ifndef _SELINUX_AVC_SS_H_ +#define _SELINUX_AVC_SS_H_ + +#include <linux/types.h> + +int avc_ss_reset(u32 seqno); + +/* Class/perm mapping support */ +struct security_class_mapping { + const char *name; + const char *perms[sizeof(u32) * 8 + 1]; +}; + +extern const struct security_class_mapping secclass_map[]; + +#endif /* _SELINUX_AVC_SS_H_ */ diff --git a/security/selinux/include/classmap.h b/security/selinux/include/classmap.h new file mode 100644 index 000000000..90cb61b16 --- /dev/null +++ b/security/selinux/include/classmap.h @@ -0,0 +1,193 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#define COMMON_FILE_SOCK_PERMS \ + "ioctl", "read", "write", "create", "getattr", "setattr", "lock", \ + "relabelfrom", "relabelto", "append", "map" + +#define COMMON_FILE_PERMS \ + COMMON_FILE_SOCK_PERMS, "unlink", "link", "rename", "execute", \ + "quotaon", "mounton", "audit_access", "open", "execmod", \ + "watch", "watch_mount", "watch_sb", "watch_with_perm", \ + "watch_reads", "watch_mountns" + +#define COMMON_SOCK_PERMS \ + COMMON_FILE_SOCK_PERMS, "bind", "connect", "listen", "accept", \ + "getopt", "setopt", "shutdown", "recvfrom", "sendto", \ + "name_bind" + +#define COMMON_IPC_PERMS \ + "create", "destroy", "getattr", "setattr", "read", "write", \ + "associate", "unix_read", "unix_write" + +#define COMMON_CAP_PERMS \ + "chown", "dac_override", "dac_read_search", "fowner", "fsetid", \ + "kill", "setgid", "setuid", "setpcap", "linux_immutable", \ + "net_bind_service", "net_broadcast", "net_admin", "net_raw", \ + "ipc_lock", "ipc_owner", "sys_module", "sys_rawio", \ + "sys_chroot", "sys_ptrace", "sys_pacct", "sys_admin", \ + "sys_boot", "sys_nice", "sys_resource", "sys_time", \ + "sys_tty_config", "mknod", "lease", "audit_write", \ + "audit_control", "setfcap" + +#define COMMON_CAP2_PERMS \ + "mac_override", "mac_admin", "syslog", "wake_alarm", "block_suspend", \ + "audit_read", "perfmon", "bpf", "checkpoint_restore" + +#ifdef __KERNEL__ /* avoid this check when building host programs */ +#include <linux/capability.h> + +#if CAP_LAST_CAP > CAP_CHECKPOINT_RESTORE +#error New capability defined, please update COMMON_CAP2_PERMS. +#endif +#endif + +/* + * Note: The name for any socket class should be suffixed by "socket", + * and doesn't contain more than one substr of "socket". + */ +const struct security_class_mapping secclass_map[] = { + { "security", + { "compute_av", "compute_create", "compute_member", "check_context", + "load_policy", "compute_relabel", "compute_user", "setenforce", + "setbool", "setsecparam", "setcheckreqprot", "read_policy", + "validate_trans", NULL } }, + { "process", + { "fork", "transition", "sigchld", "sigkill", + "sigstop", "signull", "signal", "ptrace", + "getsched", "setsched", "getsession", "getpgid", + "setpgid", "getcap", "setcap", "share", + "getattr", "setexec", "setfscreate", "noatsecure", + "siginh", "setrlimit", "rlimitinh", "dyntransition", + "setcurrent", "execmem", "execstack", "execheap", + "setkeycreate", "setsockcreate", "getrlimit", NULL } }, + { "process2", { "nnp_transition", "nosuid_transition", NULL } }, + { "system", + { "ipc_info", "syslog_read", "syslog_mod", "syslog_console", + "module_request", "module_load", "firmware_load", + "kexec_image_load", "kexec_initramfs_load", "policy_load", + "x509_certificate_load", NULL } }, + { "capability", { COMMON_CAP_PERMS, NULL } }, + { "filesystem", + { "mount", "remount", "unmount", "getattr", "relabelfrom", + "relabelto", "associate", "quotamod", "quotaget", "watch", NULL } }, + { "file", + { COMMON_FILE_PERMS, "execute_no_trans", "entrypoint", NULL } }, + { "dir", + { COMMON_FILE_PERMS, "add_name", "remove_name", "reparent", "search", + "rmdir", NULL } }, + { "fd", { "use", NULL } }, + { "lnk_file", { COMMON_FILE_PERMS, NULL } }, + { "chr_file", { COMMON_FILE_PERMS, NULL } }, + { "blk_file", { COMMON_FILE_PERMS, NULL } }, + { "sock_file", { COMMON_FILE_PERMS, NULL } }, + { "fifo_file", { COMMON_FILE_PERMS, NULL } }, + { "socket", { COMMON_SOCK_PERMS, NULL } }, + { "tcp_socket", + { COMMON_SOCK_PERMS, "node_bind", "name_connect", NULL } }, + { "udp_socket", { COMMON_SOCK_PERMS, "node_bind", NULL } }, + { "rawip_socket", { COMMON_SOCK_PERMS, "node_bind", NULL } }, + { "node", { "recvfrom", "sendto", NULL } }, + { "netif", { "ingress", "egress", NULL } }, + { "netlink_socket", { COMMON_SOCK_PERMS, NULL } }, + { "packet_socket", { COMMON_SOCK_PERMS, NULL } }, + { "key_socket", { COMMON_SOCK_PERMS, NULL } }, + { "unix_stream_socket", { COMMON_SOCK_PERMS, "connectto", NULL } }, + { "unix_dgram_socket", { COMMON_SOCK_PERMS, NULL } }, + { "sem", { COMMON_IPC_PERMS, NULL } }, + { "msg", { "send", "receive", NULL } }, + { "msgq", { COMMON_IPC_PERMS, "enqueue", NULL } }, + { "shm", { COMMON_IPC_PERMS, "lock", NULL } }, + { "ipc", { COMMON_IPC_PERMS, NULL } }, + { "netlink_route_socket", + { COMMON_SOCK_PERMS, "nlmsg_read", "nlmsg_write", "nlmsg", NULL } }, + { "netlink_tcpdiag_socket", + { COMMON_SOCK_PERMS, "nlmsg_read", "nlmsg_write", "nlmsg", NULL } }, + { "netlink_nflog_socket", { COMMON_SOCK_PERMS, NULL } }, + { "netlink_xfrm_socket", + { COMMON_SOCK_PERMS, "nlmsg_read", "nlmsg_write", "nlmsg", NULL } }, + { "netlink_selinux_socket", { COMMON_SOCK_PERMS, NULL } }, + { "netlink_iscsi_socket", { COMMON_SOCK_PERMS, NULL } }, + { "netlink_audit_socket", + { COMMON_SOCK_PERMS, "nlmsg_read", "nlmsg_write", "nlmsg_relay", + "nlmsg_readpriv", "nlmsg_tty_audit", "nlmsg", NULL } }, + { "netlink_fib_lookup_socket", { COMMON_SOCK_PERMS, NULL } }, + { "netlink_connector_socket", { COMMON_SOCK_PERMS, NULL } }, + { "netlink_netfilter_socket", { COMMON_SOCK_PERMS, NULL } }, + { "netlink_dnrt_socket", { COMMON_SOCK_PERMS, NULL } }, + { "association", + { "sendto", "recvfrom", "setcontext", "polmatch", NULL } }, + { "netlink_kobject_uevent_socket", { COMMON_SOCK_PERMS, NULL } }, + { "netlink_generic_socket", { COMMON_SOCK_PERMS, NULL } }, + { "netlink_scsitransport_socket", { COMMON_SOCK_PERMS, NULL } }, + { "netlink_rdma_socket", { COMMON_SOCK_PERMS, NULL } }, + { "netlink_crypto_socket", { COMMON_SOCK_PERMS, NULL } }, + { "appletalk_socket", { COMMON_SOCK_PERMS, NULL } }, + { "packet", + { "send", "recv", "relabelto", "forward_in", "forward_out", NULL } }, + { "key", + { "view", "read", "write", "search", "link", "setattr", "create", + NULL } }, + { "memprotect", { "mmap_zero", NULL } }, + { "peer", { "recv", NULL } }, + { "capability2", { COMMON_CAP2_PERMS, NULL } }, + { "kernel_service", { "use_as_override", "create_files_as", NULL } }, + { "tun_socket", { COMMON_SOCK_PERMS, "attach_queue", NULL } }, + { "binder", + { "impersonate", "call", "set_context_mgr", "transfer", NULL } }, + { "cap_userns", { COMMON_CAP_PERMS, NULL } }, + { "cap2_userns", { COMMON_CAP2_PERMS, NULL } }, + { "sctp_socket", + { COMMON_SOCK_PERMS, "node_bind", "name_connect", "association", + NULL } }, + { "icmp_socket", { COMMON_SOCK_PERMS, "node_bind", NULL } }, + { "ax25_socket", { COMMON_SOCK_PERMS, NULL } }, + { "ipx_socket", { COMMON_SOCK_PERMS, NULL } }, + { "netrom_socket", { COMMON_SOCK_PERMS, NULL } }, + { "atmpvc_socket", { COMMON_SOCK_PERMS, NULL } }, + { "x25_socket", { COMMON_SOCK_PERMS, NULL } }, + { "rose_socket", { COMMON_SOCK_PERMS, NULL } }, + { "decnet_socket", { COMMON_SOCK_PERMS, NULL } }, + { "atmsvc_socket", { COMMON_SOCK_PERMS, NULL } }, + { "rds_socket", { COMMON_SOCK_PERMS, NULL } }, + { "irda_socket", { COMMON_SOCK_PERMS, NULL } }, + { "pppox_socket", { COMMON_SOCK_PERMS, NULL } }, + { "llc_socket", { COMMON_SOCK_PERMS, NULL } }, + { "can_socket", { COMMON_SOCK_PERMS, NULL } }, + { "tipc_socket", { COMMON_SOCK_PERMS, NULL } }, + { "bluetooth_socket", { COMMON_SOCK_PERMS, NULL } }, + { "iucv_socket", { COMMON_SOCK_PERMS, NULL } }, + { "rxrpc_socket", { COMMON_SOCK_PERMS, NULL } }, + { "isdn_socket", { COMMON_SOCK_PERMS, NULL } }, + { "phonet_socket", { COMMON_SOCK_PERMS, NULL } }, + { "ieee802154_socket", { COMMON_SOCK_PERMS, NULL } }, + { "caif_socket", { COMMON_SOCK_PERMS, NULL } }, + { "alg_socket", { COMMON_SOCK_PERMS, NULL } }, + { "nfc_socket", { COMMON_SOCK_PERMS, NULL } }, + { "vsock_socket", { COMMON_SOCK_PERMS, NULL } }, + { "kcm_socket", { COMMON_SOCK_PERMS, NULL } }, + { "qipcrtr_socket", { COMMON_SOCK_PERMS, NULL } }, + { "smc_socket", { COMMON_SOCK_PERMS, NULL } }, + { "infiniband_pkey", { "access", NULL } }, + { "infiniband_endport", { "manage_subnet", NULL } }, + { "bpf", + { "map_create", "map_read", "map_write", "prog_load", "prog_run", + "map_create_as", "prog_load_as", NULL } }, + { "xdp_socket", { COMMON_SOCK_PERMS, NULL } }, + { "mctp_socket", { COMMON_SOCK_PERMS, NULL } }, + { "perf_event", + { "open", "cpu", "kernel", "tracepoint", "read", "write", NULL } }, + { "anon_inode", { COMMON_FILE_PERMS, NULL } }, + { "io_uring", { "override_creds", "sqpoll", "cmd", "allowed", NULL } }, + { "user_namespace", { "create", NULL } }, + { "memfd_file", + { COMMON_FILE_PERMS, "execute_no_trans", "entrypoint", NULL } }, + /* last one */ { NULL, {} } +}; + +#ifdef __KERNEL__ /* avoid this check when building host programs */ +#include <linux/socket.h> + +#if PF_MAX > 46 +#error New address family defined, please update secclass_map. +#endif +#endif diff --git a/security/selinux/include/conditional.h b/security/selinux/include/conditional.h new file mode 100644 index 000000000..060833e2d --- /dev/null +++ b/security/selinux/include/conditional.h @@ -0,0 +1,23 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Interface to booleans in the security server. This is exported + * for the selinuxfs. + * + * Author: Karl MacMillan <kmacmillan@tresys.com> + * + * Copyright (C) 2003 - 2004 Tresys Technology, LLC + */ + +#ifndef _SELINUX_CONDITIONAL_H_ +#define _SELINUX_CONDITIONAL_H_ + +#include "security.h" + +int security_get_bools(struct selinux_policy *policy, u32 *len, char ***names, + int **values); + +int security_set_bools(u32 len, const int *values); + +int security_get_bool_value(u32 index); + +#endif diff --git a/security/selinux/include/hash.h b/security/selinux/include/hash.h new file mode 100644 index 000000000..18956dbef --- /dev/null +++ b/security/selinux/include/hash.h @@ -0,0 +1,47 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +#ifndef _SELINUX_HASH_H_ +#define _SELINUX_HASH_H_ + +/* + * Based on MurmurHash3, written by Austin Appleby and placed in the + * public domain. + */ +static inline u32 av_hash(u32 key1, u32 key2, u32 key3, u32 mask) +{ + static const u32 c1 = 0xcc9e2d51; + static const u32 c2 = 0x1b873593; + static const u32 r1 = 15; + static const u32 r2 = 13; + static const u32 m = 5; + static const u32 n = 0xe6546b64; + + u32 hash = 0; + +#define mix(input) \ + do { \ + u32 v = input; \ + v *= c1; \ + v = (v << r1) | (v >> (32 - r1)); \ + v *= c2; \ + hash ^= v; \ + hash = (hash << r2) | (hash >> (32 - r2)); \ + hash = hash * m + n; \ + } while (0) + + mix(key1); + mix(key2); + mix(key3); + +#undef mix + + hash ^= hash >> 16; + hash *= 0x85ebca6b; + hash ^= hash >> 13; + hash *= 0xc2b2ae35; + hash ^= hash >> 16; + + return hash & mask; +} + +#endif /* _SELINUX_HASH_H_ */ diff --git a/security/selinux/include/ibpkey.h b/security/selinux/include/ibpkey.h new file mode 100644 index 000000000..875b05584 --- /dev/null +++ b/security/selinux/include/ibpkey.h @@ -0,0 +1,35 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * pkey table + * + * SELinux must keep a mapping of pkeys to labels/SIDs. This + * mapping is maintained as part of the normal policy but a fast cache is + * needed to reduce the lookup overhead. + */ + +/* + * (c) Mellanox Technologies, 2016 + */ + +#ifndef _SELINUX_IB_PKEY_H +#define _SELINUX_IB_PKEY_H + +#include <linux/types.h> +#include "flask.h" + +#ifdef CONFIG_SECURITY_INFINIBAND +void sel_ib_pkey_flush(void); +int sel_ib_pkey_sid(u64 subnet_prefix, u16 pkey, u32 *sid); +#else +static inline void sel_ib_pkey_flush(void) +{ + return; +} +static inline int sel_ib_pkey_sid(u64 subnet_prefix, u16 pkey, u32 *sid) +{ + *sid = SECINITSID_UNLABELED; + return 0; +} +#endif + +#endif diff --git a/security/selinux/include/ima.h b/security/selinux/include/ima.h new file mode 100644 index 000000000..d7d18f030 --- /dev/null +++ b/security/selinux/include/ima.h @@ -0,0 +1,32 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * Copyright (C) 2021 Microsoft Corporation + * + * Author: Lakshmi Ramasubramanian (nramas@linux.microsoft.com) + * + * Measure critical data structures maintained by SELinux + * using IMA subsystem. + */ + +#ifndef _SELINUX_IMA_H_ +#define _SELINUX_IMA_H_ + +#include "security.h" + +#ifdef CONFIG_IMA +void __init selinux_ima_config_len_init(void); +extern void selinux_ima_measure_state(void); +extern void selinux_ima_measure_state_locked(void); +#else +static inline void selinux_ima_config_len_init(void) +{ +} +static inline void selinux_ima_measure_state(void) +{ +} +static inline void selinux_ima_measure_state_locked(void) +{ +} +#endif + +#endif /* _SELINUX_IMA_H_ */ diff --git a/security/selinux/include/initcalls.h b/security/selinux/include/initcalls.h new file mode 100644 index 000000000..6674cf489 --- /dev/null +++ b/security/selinux/include/initcalls.h @@ -0,0 +1,19 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * SELinux initcalls + */ + +#ifndef _SELINUX_INITCALLS_H +#define _SELINUX_INITCALLS_H + +int init_sel_fs(void); +int sel_netport_init(void); +int sel_netnode_init(void); +int sel_netif_init(void); +int sel_netlink_init(void); +int sel_ib_pkey_init(void); +int selinux_nf_ip_init(void); + +int selinux_initcall(void); + +#endif diff --git a/security/selinux/include/initial_sid_to_string.h b/security/selinux/include/initial_sid_to_string.h new file mode 100644 index 000000000..d7ba60b62 --- /dev/null +++ b/security/selinux/include/initial_sid_to_string.h @@ -0,0 +1,38 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifdef __KERNEL__ +#include <linux/stddef.h> +#else +#include <stddef.h> +#endif + +static const char *const initial_sid_to_string[] = { + NULL, /* zero placeholder, not used */ + "kernel", /* kernel / SECINITSID_KERNEL */ + "security", /* security / SECINITSID_SECURITY */ + "unlabeled", /* unlabeled / SECINITSID_UNLABELED */ + NULL, /* fs */ + "file", /* file / SECINITSID_FILE */ + NULL, /* file_labels */ + "init", /* init / SECINITSID_INIT */ + "any_socket", /* any_socket / SECINITSID_ANY_SOCKET */ + "port", /* port / SECINITSID_PORT */ + "netif", /* netif / SECINITSID_NETIF */ + "netmsg", /* netmsg / SECINITSID_NETMSG */ + "node", /* node / SECINITSID_NODE */ + NULL, /* igmp_packet */ + NULL, /* icmp_socket */ + NULL, /* tcp_socket */ + NULL, /* sysctl_modprobe */ + NULL, /* sysctl */ + NULL, /* sysctl_fs */ + NULL, /* sysctl_kernel */ + NULL, /* sysctl_net */ + NULL, /* sysctl_net_unix */ + NULL, /* sysctl_vm */ + NULL, /* sysctl_dev */ + NULL, /* kmod */ + NULL, /* policy */ + NULL, /* scmp_packet */ + "devnull", /* devnull / SECINITSID_DEVNULL */ +}; diff --git a/security/selinux/include/netif.h b/security/selinux/include/netif.h new file mode 100644 index 000000000..2838bdc17 --- /dev/null +++ b/security/selinux/include/netif.h @@ -0,0 +1,24 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Network interface table. + * + * Network interfaces (devices) do not have a security field, so we + * maintain a table associating each interface with a SID. + * + * Author: James Morris <jmorris@redhat.com> + * + * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com> + * Copyright (C) 2007 Hewlett-Packard Development Company, L.P. + * Paul Moore <paul@paul-moore.com> + */ + +#ifndef _SELINUX_NETIF_H_ +#define _SELINUX_NETIF_H_ + +#include <net/net_namespace.h> + +void sel_netif_flush(void); + +int sel_netif_sid(struct net *ns, int ifindex, u32 *sid); + +#endif /* _SELINUX_NETIF_H_ */ diff --git a/security/selinux/include/netlabel.h b/security/selinux/include/netlabel.h new file mode 100644 index 000000000..5731c0dcd --- /dev/null +++ b/security/selinux/include/netlabel.h @@ -0,0 +1,137 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * SELinux interface to the NetLabel subsystem + * + * Author: Paul Moore <paul@paul-moore.com> + */ + +/* + * (c) Copyright Hewlett-Packard Development Company, L.P., 2006 + */ + +#ifndef _SELINUX_NETLABEL_H_ +#define _SELINUX_NETLABEL_H_ + +#include <linux/types.h> +#include <linux/fs.h> +#include <linux/net.h> +#include <linux/skbuff.h> +#include <net/sock.h> +#include <net/request_sock.h> +#include <net/sctp/structs.h> + +#include "avc.h" +#include "objsec.h" + +#ifdef CONFIG_NETLABEL +void selinux_netlbl_cache_invalidate(void); + +void selinux_netlbl_err(struct sk_buff *skb, u16 family, int error, + int gateway); + +void selinux_netlbl_sk_security_free(struct sk_security_struct *sksec); +void selinux_netlbl_sk_security_reset(struct sk_security_struct *sksec); + +int selinux_netlbl_skbuff_getsid(struct sk_buff *skb, u16 family, u32 *type, + u32 *sid); +int selinux_netlbl_skbuff_setsid(struct sk_buff *skb, u16 family, u32 sid); +int selinux_netlbl_sctp_assoc_request(struct sctp_association *asoc, + struct sk_buff *skb); +int selinux_netlbl_inet_conn_request(struct request_sock *req, u16 family); +void selinux_netlbl_inet_csk_clone(struct sock *sk, u16 family); +void selinux_netlbl_sctp_sk_clone(struct sock *sk, struct sock *newsk); +int selinux_netlbl_socket_post_create(struct sock *sk, u16 family); +int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec, + struct sk_buff *skb, u16 family, + struct common_audit_data *ad); +int selinux_netlbl_socket_setsockopt(struct socket *sock, int level, + int optname); +int selinux_netlbl_socket_connect(struct sock *sk, struct sockaddr *addr); +int selinux_netlbl_socket_connect_locked(struct sock *sk, + struct sockaddr *addr); + +#else +static inline void selinux_netlbl_cache_invalidate(void) +{ + return; +} + +static inline void selinux_netlbl_err(struct sk_buff *skb, u16 family, + int error, int gateway) +{ + return; +} + +static inline void +selinux_netlbl_sk_security_free(struct sk_security_struct *sksec) +{ + return; +} + +static inline void +selinux_netlbl_sk_security_reset(struct sk_security_struct *sksec) +{ + return; +} + +static inline int selinux_netlbl_skbuff_getsid(struct sk_buff *skb, u16 family, + u32 *type, u32 *sid) +{ + *type = NETLBL_NLTYPE_NONE; + *sid = SECSID_NULL; + return 0; +} +static inline int selinux_netlbl_skbuff_setsid(struct sk_buff *skb, u16 family, + u32 sid) +{ + return 0; +} + +static inline int +selinux_netlbl_sctp_assoc_request(struct sctp_association *asoc, + struct sk_buff *skb) +{ + return 0; +} +static inline int selinux_netlbl_inet_conn_request(struct request_sock *req, + u16 family) +{ + return 0; +} +static inline void selinux_netlbl_inet_csk_clone(struct sock *sk, u16 family) +{ + return; +} +static inline void selinux_netlbl_sctp_sk_clone(struct sock *sk, + struct sock *newsk) +{ + return; +} +static inline int selinux_netlbl_socket_post_create(struct sock *sk, u16 family) +{ + return 0; +} +static inline int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec, + struct sk_buff *skb, u16 family, + struct common_audit_data *ad) +{ + return 0; +} +static inline int selinux_netlbl_socket_setsockopt(struct socket *sock, + int level, int optname) +{ + return 0; +} +static inline int selinux_netlbl_socket_connect(struct sock *sk, + struct sockaddr *addr) +{ + return 0; +} +static inline int selinux_netlbl_socket_connect_locked(struct sock *sk, + struct sockaddr *addr) +{ + return 0; +} +#endif /* CONFIG_NETLABEL */ + +#endif diff --git a/security/selinux/include/netnode.h b/security/selinux/include/netnode.h new file mode 100644 index 000000000..e4dc904c3 --- /dev/null +++ b/security/selinux/include/netnode.h @@ -0,0 +1,26 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Network node table + * + * SELinux must keep a mapping of network nodes to labels/SIDs. This + * mapping is maintained as part of the normal policy but a fast cache is + * needed to reduce the lookup overhead since most of these queries happen on + * a per-packet basis. + * + * Author: Paul Moore <paul@paul-moore.com> + */ + +/* + * (c) Copyright Hewlett-Packard Development Company, L.P., 2007 + */ + +#ifndef _SELINUX_NETNODE_H +#define _SELINUX_NETNODE_H + +#include <linux/types.h> + +void sel_netnode_flush(void); + +int sel_netnode_sid(const void *addr, u16 family, u32 *sid); + +#endif diff --git a/security/selinux/include/netport.h b/security/selinux/include/netport.h new file mode 100644 index 000000000..9096a8289 --- /dev/null +++ b/security/selinux/include/netport.h @@ -0,0 +1,25 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Network port table + * + * SELinux must keep a mapping of network ports to labels/SIDs. This + * mapping is maintained as part of the normal policy but a fast cache is + * needed to reduce the lookup overhead. + * + * Author: Paul Moore <paul@paul-moore.com> + */ + +/* + * (c) Copyright Hewlett-Packard Development Company, L.P., 2008 + */ + +#ifndef _SELINUX_NETPORT_H +#define _SELINUX_NETPORT_H + +#include <linux/types.h> + +void sel_netport_flush(void); + +int sel_netport_sid(u8 protocol, u16 pnum, u32 *sid); + +#endif diff --git a/security/selinux/include/objsec.h b/security/selinux/include/objsec.h new file mode 100644 index 000000000..3c0a16ec9 --- /dev/null +++ b/security/selinux/include/objsec.h @@ -0,0 +1,290 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Security-Enhanced Linux (SELinux) security module + * + * This file contains the SELinux security data structures for kernel objects. + * + * Author(s): Stephen Smalley, <stephen.smalley.work@gmail.com> + * Chris Vance, <cvance@nai.com> + * Wayne Salamon, <wsalamon@nai.com> + * James Morris <jmorris@redhat.com> + * + * Copyright (C) 2001,2002 Networks Associates Technology, Inc. + * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com> + * Copyright (C) 2016 Mellanox Technologies + */ + +#ifndef _SELINUX_OBJSEC_H_ +#define _SELINUX_OBJSEC_H_ + +#include <linux/list.h> +#include <linux/sched.h> +#include <linux/fs.h> +#include <linux/binfmts.h> +#include <linux/in.h> +#include <linux/spinlock.h> +#include <linux/lsm_hooks.h> +#include <linux/msg.h> +#include <net/net_namespace.h> +#include <linux/bpf.h> +#include "flask.h" +#include "avc.h" + +struct avdc_entry { + u32 isid; /* inode SID */ + struct av_decision avd; /* av decision */ +}; + +struct cred_security_struct { + u32 osid; /* SID prior to last execve */ + u32 sid; /* current SID */ + u32 exec_sid; /* exec SID */ + u32 create_sid; /* fscreate SID */ + u32 keycreate_sid; /* keycreate SID */ + u32 sockcreate_sid; /* fscreate SID */ +} __randomize_layout; + +struct task_security_struct { +#define TSEC_AVDC_DIR_SIZE (1 << 2) + struct { + u32 sid; /* current SID for cached entries */ + u32 seqno; /* AVC sequence number */ + unsigned int dir_spot; /* dir cache index to check first */ + struct avdc_entry dir[TSEC_AVDC_DIR_SIZE]; /* dir entries */ + bool permissive_neveraudit; /* permissive and neveraudit */ + } avdcache; +} __randomize_layout; + +static inline bool task_avdcache_permnoaudit(struct task_security_struct *tsec, + u32 sid) +{ + return (tsec->avdcache.permissive_neveraudit && + sid == tsec->avdcache.sid && + tsec->avdcache.seqno == avc_policy_seqno()); +} + +enum label_initialized { + LABEL_INVALID, /* invalid or not initialized */ + LABEL_INITIALIZED, /* initialized */ + LABEL_PENDING +}; + +struct inode_security_struct { + struct inode *inode; /* back pointer to inode object */ + struct list_head list; /* list of inode_security_struct */ + u32 task_sid; /* SID of creating task */ + u32 sid; /* SID of this object */ + u16 sclass; /* security class of this object */ + unsigned char initialized; /* initialization flag */ + spinlock_t lock; +}; + +struct file_security_struct { + u32 sid; /* SID of open file description */ + u32 fown_sid; /* SID of file owner (for SIGIO) */ + u32 isid; /* SID of inode at the time of file open */ + u32 pseqno; /* Policy seqno at the time of file open */ +}; + +struct backing_file_security_struct { + u32 uf_sid; /* associated user file fsec->sid */ +}; + +struct superblock_security_struct { + u32 sid; /* SID of file system superblock */ + u32 def_sid; /* default SID for labeling */ + u32 mntpoint_sid; /* SECURITY_FS_USE_MNTPOINT context for files */ + u32 creator_sid; /* SID of privileged process */ + unsigned short behavior; /* labeling behavior */ + unsigned short flags; /* which mount options were specified */ + struct mutex lock; + struct list_head isec_head; + spinlock_t isec_lock; +}; + +struct msg_security_struct { + u32 sid; /* SID of message */ +}; + +struct ipc_security_struct { + u16 sclass; /* security class of this object */ + u32 sid; /* SID of IPC resource */ +}; + +struct netif_security_struct { + const struct net *ns; /* network namespace */ + int ifindex; /* device index */ + u32 sid; /* SID for this interface */ +}; + +struct netnode_security_struct { + union { + __be32 ipv4; /* IPv4 node address */ + struct in6_addr ipv6; /* IPv6 node address */ + } addr; + u32 sid; /* SID for this node */ + u16 family; /* address family */ +}; + +struct netport_security_struct { + u32 sid; /* SID for this node */ + u16 port; /* port number */ + u8 protocol; /* transport protocol */ +}; + +struct sk_security_struct { +#ifdef CONFIG_NETLABEL + enum { /* NetLabel state */ + NLBL_UNSET = 0, + NLBL_REQUIRE, + NLBL_LABELED, + NLBL_REQSKB, + NLBL_CONNLABELED, + } nlbl_state; + struct netlbl_lsm_secattr *nlbl_secattr; /* NetLabel sec attributes */ +#endif + u32 sid; /* SID of this object */ + u32 peer_sid; /* SID of peer */ + u16 sclass; /* sock security class */ + enum { /* SCTP association state */ + SCTP_ASSOC_UNSET = 0, + SCTP_ASSOC_SET, + } sctp_assoc_state; +}; + +struct tun_security_struct { + u32 sid; /* SID for the tun device sockets */ +}; + +struct key_security_struct { + u32 sid; /* SID of key */ +}; + +struct ib_security_struct { + u32 sid; /* SID of the queue pair or MAD agent */ +}; + +struct pkey_security_struct { + u64 subnet_prefix; /* Port subnet prefix */ + u16 pkey; /* PKey number */ + u32 sid; /* SID of pkey */ +}; + +struct bpf_security_struct { + u32 sid; /* SID of bpf obj creator */ + u32 perms; /* permissions for allowed bpf token commands */ + u32 grantor_sid; /* SID of token grantor */ +}; + +struct perf_event_security_struct { + u32 sid; /* SID of perf_event obj creator */ +}; + +extern struct lsm_blob_sizes selinux_blob_sizes; +static inline struct cred_security_struct *selinux_cred(const struct cred *cred) +{ + return cred->security + selinux_blob_sizes.lbs_cred; +} + +static inline struct task_security_struct * +selinux_task(const struct task_struct *task) +{ + return task->security + selinux_blob_sizes.lbs_task; +} + +static inline struct file_security_struct *selinux_file(const struct file *file) +{ + return file->f_security + selinux_blob_sizes.lbs_file; +} + +static inline struct backing_file_security_struct * +selinux_backing_file(const struct file *backing_file) +{ + void *blob = backing_file_security(backing_file); + return blob + selinux_blob_sizes.lbs_backing_file; +} + +static inline struct inode_security_struct * +selinux_inode(const struct inode *inode) +{ + if (unlikely(!inode->i_security)) + return NULL; + return inode->i_security + selinux_blob_sizes.lbs_inode; +} + +static inline struct msg_security_struct * +selinux_msg_msg(const struct msg_msg *msg_msg) +{ + return msg_msg->security + selinux_blob_sizes.lbs_msg_msg; +} + +static inline struct ipc_security_struct * +selinux_ipc(const struct kern_ipc_perm *ipc) +{ + return ipc->security + selinux_blob_sizes.lbs_ipc; +} + +/* + * get the subjective security ID of the current task + */ +static inline u32 current_sid(void) +{ + const struct cred_security_struct *crsec = selinux_cred(current_cred()); + + return crsec->sid; +} + +static inline struct superblock_security_struct * +selinux_superblock(const struct super_block *superblock) +{ + return superblock->s_security + selinux_blob_sizes.lbs_superblock; +} + +#ifdef CONFIG_KEYS +static inline struct key_security_struct *selinux_key(const struct key *key) +{ + return key->security + selinux_blob_sizes.lbs_key; +} +#endif /* CONFIG_KEYS */ + +static inline struct sk_security_struct *selinux_sock(const struct sock *sock) +{ + return sock->sk_security + selinux_blob_sizes.lbs_sock; +} + +static inline struct tun_security_struct *selinux_tun_dev(void *security) +{ + return security + selinux_blob_sizes.lbs_tun_dev; +} + +static inline struct ib_security_struct *selinux_ib(void *ib_sec) +{ + return ib_sec + selinux_blob_sizes.lbs_ib; +} + +static inline struct perf_event_security_struct * +selinux_perf_event(void *perf_event) +{ + return perf_event + selinux_blob_sizes.lbs_perf_event; +} + +#ifdef CONFIG_BPF_SYSCALL +static inline struct bpf_security_struct * +selinux_bpf_map_security(struct bpf_map *map) +{ + return map->security + selinux_blob_sizes.lbs_bpf_map; +} + +static inline struct bpf_security_struct * +selinux_bpf_prog_security(struct bpf_prog *prog) +{ + return prog->aux->security + selinux_blob_sizes.lbs_bpf_prog; +} + +static inline struct bpf_security_struct * +selinux_bpf_token_security(struct bpf_token *token) +{ + return token->security + selinux_blob_sizes.lbs_bpf_token; +} +#endif /* CONFIG_BPF_SYSCALL */ +#endif /* _SELINUX_OBJSEC_H_ */ diff --git a/security/selinux/include/policycap.h b/security/selinux/include/policycap.h new file mode 100644 index 000000000..dbf39358a --- /dev/null +++ b/security/selinux/include/policycap.h @@ -0,0 +1,29 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef _SELINUX_POLICYCAP_H_ +#define _SELINUX_POLICYCAP_H_ + +/* Policy capabilities */ +enum { + POLICYDB_CAP_NETPEER, + POLICYDB_CAP_OPENPERM, + POLICYDB_CAP_EXTSOCKCLASS, + POLICYDB_CAP_ALWAYSNETWORK, + POLICYDB_CAP_CGROUPSECLABEL, + POLICYDB_CAP_NNP_NOSUID_TRANSITION, + POLICYDB_CAP_GENFS_SECLABEL_SYMLINKS, + POLICYDB_CAP_IOCTL_SKIP_CLOEXEC, + POLICYDB_CAP_USERSPACE_INITIAL_CONTEXT, + POLICYDB_CAP_NETLINK_XPERM, + POLICYDB_CAP_NETIF_WILDCARD, + POLICYDB_CAP_GENFS_SECLABEL_WILDCARD, + POLICYDB_CAP_FUNCTIONFS_SECLABEL, + POLICYDB_CAP_MEMFD_CLASS, + POLICYDB_CAP_BPF_TOKEN_PERMS, + __POLICYDB_CAP_MAX +}; +#define POLICYDB_CAP_MAX (__POLICYDB_CAP_MAX - 1) + +extern const char *const selinux_policycap_names[__POLICYDB_CAP_MAX]; + +#endif /* _SELINUX_POLICYCAP_H_ */ diff --git a/security/selinux/include/policycap_names.h b/security/selinux/include/policycap_names.h new file mode 100644 index 000000000..6e2b808e1 --- /dev/null +++ b/security/selinux/include/policycap_names.h @@ -0,0 +1,29 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef _SELINUX_POLICYCAP_NAMES_H_ +#define _SELINUX_POLICYCAP_NAMES_H_ + +#include "policycap.h" + +/* clang-format off */ +/* Policy capability names */ +const char *const selinux_policycap_names[__POLICYDB_CAP_MAX] = { + "network_peer_controls", + "open_perms", + "extended_socket_class", + "always_check_network", + "cgroup_seclabel", + "nnp_nosuid_transition", + "genfs_seclabel_symlinks", + "ioctl_skip_cloexec", + "userspace_initial_context", + "netlink_xperm", + "netif_wildcard", + "genfs_seclabel_wildcard", + "functionfs_seclabel", + "memfd_class", + "bpf_token_perms", +}; +/* clang-format on */ + +#endif /* _SELINUX_POLICYCAP_NAMES_H_ */ diff --git a/security/selinux/include/security.h b/security/selinux/include/security.h new file mode 100644 index 000000000..a74415e3a --- /dev/null +++ b/security/selinux/include/security.h @@ -0,0 +1,414 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Security server interface. + * + * Author : Stephen Smalley, <stephen.smalley.work@gmail.com> + * + */ + +#ifndef _SELINUX_SECURITY_H_ +#define _SELINUX_SECURITY_H_ + +#include <linux/compiler.h> +#include <linux/dcache.h> +#include <linux/magic.h> +#include <linux/types.h> +#include <linux/rcupdate.h> +#include <linux/refcount.h> +#include <linux/workqueue.h> +#include <linux/delay.h> +#include <linux/printk.h> +#include "flask.h" +#include "policycap.h" + +#define SECSID_NULL 0x00000000 /* unspecified SID */ +#define SECSID_WILD 0xffffffff /* wildcard SID */ +#define SECCLASS_NULL 0x0000 /* no class */ + +/* Identify specific policy version changes */ +#define POLICYDB_VERSION_BASE 15 +#define POLICYDB_VERSION_BOOL 16 +#define POLICYDB_VERSION_IPV6 17 +#define POLICYDB_VERSION_NLCLASS 18 +#define POLICYDB_VERSION_VALIDATETRANS 19 +#define POLICYDB_VERSION_MLS 19 +#define POLICYDB_VERSION_AVTAB 20 +#define POLICYDB_VERSION_RANGETRANS 21 +#define POLICYDB_VERSION_POLCAP 22 +#define POLICYDB_VERSION_PERMISSIVE 23 +#define POLICYDB_VERSION_BOUNDARY 24 +#define POLICYDB_VERSION_FILENAME_TRANS 25 +#define POLICYDB_VERSION_ROLETRANS 26 +#define POLICYDB_VERSION_NEW_OBJECT_DEFAULTS 27 +#define POLICYDB_VERSION_DEFAULT_TYPE 28 +#define POLICYDB_VERSION_CONSTRAINT_NAMES 29 +#define POLICYDB_VERSION_XPERMS_IOCTL 30 +#define POLICYDB_VERSION_INFINIBAND 31 +#define POLICYDB_VERSION_GLBLUB 32 +#define POLICYDB_VERSION_COMP_FTRANS 33 /* compressed filename transitions */ +#define POLICYDB_VERSION_COND_XPERMS 34 /* extended permissions in conditional policies */ +#define POLICYDB_VERSION_NEVERAUDIT 35 /* neveraudit types */ + +/* Range of policy versions we understand*/ +#define POLICYDB_VERSION_MIN POLICYDB_VERSION_BASE +#define POLICYDB_VERSION_MAX POLICYDB_VERSION_NEVERAUDIT + +/* Mask for just the mount related flags */ +#define SE_MNTMASK 0x0f +/* Super block security struct flags for mount options */ +/* BE CAREFUL, these need to be the low order bits for selinux_get_mnt_opts */ +#define CONTEXT_MNT 0x01 +#define FSCONTEXT_MNT 0x02 +#define ROOTCONTEXT_MNT 0x04 +#define DEFCONTEXT_MNT 0x08 +#define SBLABEL_MNT 0x10 +/* Non-mount related flags */ +#define SE_SBINITIALIZED 0x0100 +#define SE_SBPROC 0x0200 +#define SE_SBGENFS 0x0400 +#define SE_SBGENFS_XATTR 0x0800 +#define SE_SBNATIVE 0x1000 + +#define CONTEXT_STR "context" +#define FSCONTEXT_STR "fscontext" +#define ROOTCONTEXT_STR "rootcontext" +#define DEFCONTEXT_STR "defcontext" +#define SECLABEL_STR "seclabel" + +struct netlbl_lsm_secattr; + +extern int selinux_enabled_boot; + +/* + * type_datum properties + * available at the kernel policy version >= POLICYDB_VERSION_BOUNDARY + */ +#define TYPEDATUM_PROPERTY_PRIMARY 0x0001 +#define TYPEDATUM_PROPERTY_ATTRIBUTE 0x0002 + +/* limitation of boundary depth */ +#define POLICYDB_BOUNDS_MAXDEPTH 4 + +struct selinux_policy; + +struct selinux_state { +#ifdef CONFIG_SECURITY_SELINUX_DEVELOP + bool enforcing; +#endif + bool initialized; + bool policycap[__POLICYDB_CAP_MAX]; + + struct page *status_page; + struct mutex status_lock; + + struct selinux_policy __rcu *policy; + struct mutex policy_mutex; +} __randomize_layout; + +void selinux_avc_init(void); + +extern struct selinux_state selinux_state; + +static inline bool selinux_initialized(void) +{ + /* do a synchronized load to avoid race conditions */ + return smp_load_acquire(&selinux_state.initialized); +} + +static inline void selinux_mark_initialized(void) +{ + /* do a synchronized write to avoid race conditions */ + smp_store_release(&selinux_state.initialized, true); +} + +#ifdef CONFIG_SECURITY_SELINUX_DEVELOP +static inline bool enforcing_enabled(void) +{ + return READ_ONCE(selinux_state.enforcing); +} + +static inline void enforcing_set(bool value) +{ + WRITE_ONCE(selinux_state.enforcing, value); +} +#else +static inline bool enforcing_enabled(void) +{ + return true; +} + +static inline void enforcing_set(bool value) +{ +} +#endif + +static inline bool checkreqprot_get(void) +{ + /* non-zero/true checkreqprot values are no longer supported */ + return 0; +} + +static inline bool selinux_policycap_netpeer(void) +{ + return READ_ONCE(selinux_state.policycap[POLICYDB_CAP_NETPEER]); +} + +static inline bool selinux_policycap_openperm(void) +{ + return READ_ONCE(selinux_state.policycap[POLICYDB_CAP_OPENPERM]); +} + +static inline bool selinux_policycap_extsockclass(void) +{ + return READ_ONCE(selinux_state.policycap[POLICYDB_CAP_EXTSOCKCLASS]); +} + +static inline bool selinux_policycap_alwaysnetwork(void) +{ + return READ_ONCE(selinux_state.policycap[POLICYDB_CAP_ALWAYSNETWORK]); +} + +static inline bool selinux_policycap_cgroupseclabel(void) +{ + return READ_ONCE(selinux_state.policycap[POLICYDB_CAP_CGROUPSECLABEL]); +} + +static inline bool selinux_policycap_nnp_nosuid_transition(void) +{ + return READ_ONCE( + selinux_state.policycap[POLICYDB_CAP_NNP_NOSUID_TRANSITION]); +} + +static inline bool selinux_policycap_genfs_seclabel_symlinks(void) +{ + return READ_ONCE( + selinux_state.policycap[POLICYDB_CAP_GENFS_SECLABEL_SYMLINKS]); +} + +static inline bool selinux_policycap_ioctl_skip_cloexec(void) +{ + return READ_ONCE( + selinux_state.policycap[POLICYDB_CAP_IOCTL_SKIP_CLOEXEC]); +} + +static inline bool selinux_policycap_userspace_initial_context(void) +{ + return READ_ONCE( + selinux_state.policycap[POLICYDB_CAP_USERSPACE_INITIAL_CONTEXT]); +} + +static inline bool selinux_policycap_netlink_xperm(void) +{ + return READ_ONCE( + selinux_state.policycap[POLICYDB_CAP_NETLINK_XPERM]); +} + +static inline bool selinux_policycap_functionfs_seclabel(void) +{ + return READ_ONCE( + selinux_state.policycap[POLICYDB_CAP_FUNCTIONFS_SECLABEL]); +} + +static inline bool selinux_policycap_memfd_class(void) +{ + return READ_ONCE(selinux_state.policycap[POLICYDB_CAP_MEMFD_CLASS]); +} + +static inline bool selinux_policycap_bpf_token_perms(void) +{ + return READ_ONCE( + selinux_state.policycap[POLICYDB_CAP_BPF_TOKEN_PERMS]); +} + +struct selinux_policy_convert_data; + +struct selinux_load_state { + struct selinux_policy *policy; + struct selinux_policy_convert_data *convert_data; +}; + +int security_mls_enabled(void); +int security_load_policy(void *data, size_t len, + struct selinux_load_state *load_state); +void selinux_policy_commit(struct selinux_load_state *load_state); +void selinux_policy_cancel(struct selinux_load_state *load_state); +int security_read_policy(void **data, size_t *len); +int security_read_state_kernel(void **data, size_t *len); +int security_policycap_supported(unsigned int req_cap); + +/* Maximum supported number of permissions per class */ +#define SEL_VEC_MAX 32 +struct av_decision { + u32 allowed; + u32 auditallow; + u32 auditdeny; + u32 seqno; + u32 flags; +}; + +#define XPERMS_ALLOWED 1 +#define XPERMS_AUDITALLOW 2 +#define XPERMS_DONTAUDIT 4 + +#define security_xperm_set(perms, x) ((perms)[(x) >> 5] |= 1 << ((x)&0x1f)) +#define security_xperm_test(perms, x) (1 & ((perms)[(x) >> 5] >> ((x)&0x1f))) +struct extended_perms_data { + u32 p[8]; +}; + +struct extended_perms_decision { + u8 used; + u8 driver; + u8 base_perm; + struct extended_perms_data *allowed; + struct extended_perms_data *auditallow; + struct extended_perms_data *dontaudit; +}; + +struct extended_perms { + u16 len; /* length associated decision chain */ + u8 base_perms; /* which base permissions are covered */ + struct extended_perms_data drivers; /* flag drivers that are used */ +}; + +/* definitions of av_decision.flags */ +#define AVD_FLAGS_PERMISSIVE 0x0001 +#define AVD_FLAGS_NEVERAUDIT 0x0002 + +void security_compute_av(u32 ssid, u32 tsid, u16 tclass, + struct av_decision *avd, + struct extended_perms *xperms); + +void security_compute_xperms_decision(u32 ssid, u32 tsid, u16 tclass, u8 driver, + u8 base_perm, + struct extended_perms_decision *xpermd); + +void security_compute_av_user(u32 ssid, u32 tsid, u16 tclass, + struct av_decision *avd); + +int security_transition_sid(u32 ssid, u32 tsid, u16 tclass, + const struct qstr *qstr, u32 *out_sid); + +int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass, + const char *objname, u32 *out_sid); + +int security_member_sid(u32 ssid, u32 tsid, u16 tclass, u32 *out_sid); + +int security_change_sid(u32 ssid, u32 tsid, u16 tclass, u32 *out_sid); + +int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len); + +int security_sid_to_context_force(u32 sid, char **scontext, u32 *scontext_len); + +int security_sid_to_context_inval(u32 sid, char **scontext, u32 *scontext_len); + +int security_context_to_sid(const char *scontext, u32 scontext_len, + u32 *out_sid, gfp_t gfp); + +int security_context_str_to_sid(const char *scontext, u32 *out_sid, gfp_t gfp); + +int security_context_to_sid_default(const char *scontext, u32 scontext_len, + u32 *out_sid, u32 def_sid, gfp_t gfp_flags); + +int security_context_to_sid_force(const char *scontext, u32 scontext_len, + u32 *sid); + +int security_port_sid(u8 protocol, u16 port, u32 *out_sid); + +int security_ib_pkey_sid(u64 subnet_prefix, u16 pkey_num, u32 *out_sid); + +int security_ib_endport_sid(const char *dev_name, u8 port_num, u32 *out_sid); + +int security_netif_sid(const char *name, u32 *if_sid); + +int security_node_sid(u16 domain, const void *addr, u32 addrlen, u32 *out_sid); + +int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid, + u16 tclass); + +int security_validate_transition_user(u32 oldsid, u32 newsid, u32 tasksid, + u16 tclass); + +int security_bounded_transition(u32 old_sid, u32 new_sid); + +int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid); + +int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type, u32 xfrm_sid, + u32 *peer_sid); + +int security_get_classes(struct selinux_policy *policy, char ***classes, + u32 *nclasses); +int security_get_permissions(struct selinux_policy *policy, const char *class, + char ***perms, u32 *nperms); +int security_get_reject_unknown(void); +int security_get_allow_unknown(void); + +#define SECURITY_FS_USE_XATTR 1 /* use xattr */ +#define SECURITY_FS_USE_TRANS 2 /* use transition SIDs, e.g. devpts/tmpfs */ +#define SECURITY_FS_USE_TASK 3 /* use task SIDs, e.g. pipefs/sockfs */ +#define SECURITY_FS_USE_GENFS 4 /* use the genfs support */ +#define SECURITY_FS_USE_NONE 5 /* no labeling support */ +#define SECURITY_FS_USE_MNTPOINT 6 /* use mountpoint labeling */ +#define SECURITY_FS_USE_NATIVE 7 /* use native label support */ +#define SECURITY_FS_USE_MAX 7 /* Highest SECURITY_FS_USE_XXX */ + +int security_fs_use(struct super_block *sb); + +int security_genfs_sid(const char *fstype, const char *path, u16 sclass, + u32 *sid); + +int selinux_policy_genfs_sid(struct selinux_policy *policy, const char *fstype, + const char *path, u16 sclass, u32 *sid); + +#ifdef CONFIG_NETLABEL +int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr, + u32 *sid); + +int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr); +#else +static inline int +security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr, u32 *sid) +{ + return -EIDRM; +} + +static inline int +security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr) +{ + return -ENOENT; +} +#endif /* CONFIG_NETLABEL */ + +const char *security_get_initial_sid_context(u32 sid); + +/* + * status notifier using mmap interface + */ +extern struct page *selinux_kernel_status_page(void); + +#define SELINUX_KERNEL_STATUS_VERSION 1 +struct selinux_kernel_status { + u32 version; /* version number of the structure */ + u32 sequence; /* sequence number of seqlock logic */ + u32 enforcing; /* current setting of enforcing mode */ + u32 policyload; /* times of policy reloaded */ + u32 deny_unknown; /* current setting of deny_unknown */ + /* + * The version > 0 supports above members. + */ +} __packed; + +extern void selinux_status_update_setenforce(bool enforcing); +extern void selinux_status_update_policyload(u32 seqno); +extern void selinux_complete_init(void); +extern struct path selinux_null; +extern void selnl_notify_setenforce(int val); +extern void selnl_notify_policyload(u32 seqno); +extern int selinux_nlmsg_lookup(u16 sclass, u16 nlmsg_type, u32 *perm); + +extern void avtab_cache_init(void); +extern void ebitmap_cache_init(void); +extern void hashtab_cache_init(void); +extern int security_sidtab_hash_stats(char *page); + +#endif /* _SELINUX_SECURITY_H_ */ diff --git a/security/selinux/include/xfrm.h b/security/selinux/include/xfrm.h new file mode 100644 index 000000000..de485556a --- /dev/null +++ b/security/selinux/include/xfrm.h @@ -0,0 +1,94 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * SELinux support for the XFRM LSM hooks + * + * Author : Trent Jaeger, <jaegert@us.ibm.com> + * Updated : Venkat Yekkirala, <vyekkirala@TrustedCS.com> + */ + +#ifndef _SELINUX_XFRM_H_ +#define _SELINUX_XFRM_H_ + +#include <linux/lsm_audit.h> +#include <net/flow.h> +#include <net/xfrm.h> + +int selinux_xfrm_policy_alloc(struct xfrm_sec_ctx **ctxp, + struct xfrm_user_sec_ctx *uctx, gfp_t gfp); +int selinux_xfrm_policy_clone(struct xfrm_sec_ctx *old_ctx, + struct xfrm_sec_ctx **new_ctxp); +void selinux_xfrm_policy_free(struct xfrm_sec_ctx *ctx); +int selinux_xfrm_policy_delete(struct xfrm_sec_ctx *ctx); +int selinux_xfrm_state_alloc(struct xfrm_state *x, + struct xfrm_user_sec_ctx *uctx); +int selinux_xfrm_state_alloc_acquire(struct xfrm_state *x, + struct xfrm_sec_ctx *polsec, u32 secid); +void selinux_xfrm_state_free(struct xfrm_state *x); +int selinux_xfrm_state_delete(struct xfrm_state *x); +int selinux_xfrm_policy_lookup(struct xfrm_sec_ctx *ctx, u32 fl_secid); +int selinux_xfrm_state_pol_flow_match(struct xfrm_state *x, + struct xfrm_policy *xp, + const struct flowi_common *flic); + +#ifdef CONFIG_SECURITY_NETWORK_XFRM +extern atomic_t selinux_xfrm_refcount; + +static inline int selinux_xfrm_enabled(void) +{ + return (atomic_read(&selinux_xfrm_refcount) > 0); +} + +int selinux_xfrm_sock_rcv_skb(u32 sk_sid, struct sk_buff *skb, + struct common_audit_data *ad); +int selinux_xfrm_postroute_last(u32 sk_sid, struct sk_buff *skb, + struct common_audit_data *ad, u8 proto); +int selinux_xfrm_decode_session(struct sk_buff *skb, u32 *sid, int ckall); +int selinux_xfrm_skb_sid(struct sk_buff *skb, u32 *sid); + +static inline void selinux_xfrm_notify_policyload(void) +{ + struct net *net; + + down_read(&net_rwsem); + for_each_net(net) + rt_genid_bump_all(net); + up_read(&net_rwsem); +} +#else +static inline int selinux_xfrm_enabled(void) +{ + return 0; +} + +static inline int selinux_xfrm_sock_rcv_skb(u32 sk_sid, struct sk_buff *skb, + struct common_audit_data *ad) +{ + return 0; +} + +static inline int selinux_xfrm_postroute_last(u32 sk_sid, struct sk_buff *skb, + struct common_audit_data *ad, + u8 proto) +{ + return 0; +} + +static inline int selinux_xfrm_decode_session(struct sk_buff *skb, u32 *sid, + int ckall) +{ + *sid = SECSID_NULL; + return 0; +} + +static inline void selinux_xfrm_notify_policyload(void) +{ +} + +static inline int selinux_xfrm_skb_sid(struct sk_buff *skb, u32 *sid) +{ + *sid = SECSID_NULL; + return 0; +} +#endif + +#endif /* _SELINUX_XFRM_H_ */ diff --git a/security/selinux/initcalls.c b/security/selinux/initcalls.c new file mode 100644 index 000000000..f6716a1d3 --- /dev/null +++ b/security/selinux/initcalls.c @@ -0,0 +1,52 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * SELinux initcalls + */ + +#include <linux/init.h> + +#include "initcalls.h" + +/** + * selinux_initcall - Perform the SELinux initcalls + * + * Used as a device initcall in the SELinux LSM definition. + */ +int __init selinux_initcall(void) +{ + int rc = 0, rc_tmp = 0; + + rc_tmp = init_sel_fs(); + if (!rc && rc_tmp) + rc = rc_tmp; + + rc_tmp = sel_netport_init(); + if (!rc && rc_tmp) + rc = rc_tmp; + + rc_tmp = sel_netnode_init(); + if (!rc && rc_tmp) + rc = rc_tmp; + + rc_tmp = sel_netif_init(); + if (!rc && rc_tmp) + rc = rc_tmp; + + rc_tmp = sel_netlink_init(); + if (!rc && rc_tmp) + rc = rc_tmp; + +#if defined(CONFIG_SECURITY_INFINIBAND) + rc_tmp = sel_ib_pkey_init(); + if (!rc && rc_tmp) + rc = rc_tmp; +#endif + +#if defined(CONFIG_NETFILTER) + rc_tmp = selinux_nf_ip_init(); + if (!rc && rc_tmp) + rc = rc_tmp; +#endif + + return rc; +} diff --git a/security/selinux/netif.c b/security/selinux/netif.c new file mode 100644 index 000000000..fa6d24a37 --- /dev/null +++ b/security/selinux/netif.c @@ -0,0 +1,283 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Network interface table. + * + * Network interfaces (devices) do not have a security field, so we + * maintain a table associating each interface with a SID. + * + * Author: James Morris <jmorris@redhat.com> + * + * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com> + * Copyright (C) 2007 Hewlett-Packard Development Company, L.P. + * Paul Moore <paul@paul-moore.com> + */ +#include <linux/init.h> +#include <linux/types.h> +#include <linux/slab.h> +#include <linux/stddef.h> +#include <linux/kernel.h> +#include <linux/list.h> +#include <linux/notifier.h> +#include <linux/netdevice.h> +#include <linux/rcupdate.h> +#include <net/net_namespace.h> + +#include "initcalls.h" +#include "security.h" +#include "objsec.h" +#include "netif.h" + +#define SEL_NETIF_HASH_SIZE 64 +#define SEL_NETIF_HASH_MAX 1024 + +struct sel_netif { + struct list_head list; + struct netif_security_struct nsec; + struct rcu_head rcu_head; +}; + +static u32 sel_netif_total; +static DEFINE_SPINLOCK(sel_netif_lock); +static struct list_head sel_netif_hash[SEL_NETIF_HASH_SIZE]; + +/** + * sel_netif_hashfn - Hashing function for the interface table + * @ns: the network namespace + * @ifindex: the network interface + * + * Description: + * This is the hashing function for the network interface table, it returns the + * bucket number for the given interface. + * + */ +static inline u32 sel_netif_hashfn(const struct net *ns, int ifindex) +{ + return (((uintptr_t)ns + ifindex) & (SEL_NETIF_HASH_SIZE - 1)); +} + +/** + * sel_netif_find - Search for an interface record + * @ns: the network namespace + * @ifindex: the network interface + * + * Description: + * Search the network interface table and return the record matching @ifindex. + * If an entry can not be found in the table return NULL. + * + */ +static inline struct sel_netif *sel_netif_find(const struct net *ns, + int ifindex) +{ + u32 idx = sel_netif_hashfn(ns, ifindex); + struct sel_netif *netif; + + list_for_each_entry_rcu(netif, &sel_netif_hash[idx], list) + if (net_eq(netif->nsec.ns, ns) && + netif->nsec.ifindex == ifindex) + return netif; + + return NULL; +} + +/** + * sel_netif_insert - Insert a new interface into the table + * @netif: the new interface record + * + * Description: + * Add a new interface record to the network interface hash table. Returns + * zero on success, negative values on failure. + * + */ +static int sel_netif_insert(struct sel_netif *netif) +{ + u32 idx; + + if (sel_netif_total >= SEL_NETIF_HASH_MAX) + return -ENOSPC; + + idx = sel_netif_hashfn(netif->nsec.ns, netif->nsec.ifindex); + list_add_rcu(&netif->list, &sel_netif_hash[idx]); + sel_netif_total++; + + return 0; +} + +/** + * sel_netif_destroy - Remove an interface record from the table + * @netif: the existing interface record + * + * Description: + * Remove an existing interface record from the network interface table. + * + */ +static void sel_netif_destroy(struct sel_netif *netif) +{ + list_del_rcu(&netif->list); + sel_netif_total--; + kfree_rcu(netif, rcu_head); +} + +/** + * sel_netif_sid_slow - Lookup the SID of a network interface using the policy + * @ns: the network namespace + * @ifindex: the network interface + * @sid: interface SID + * + * Description: + * This function determines the SID of a network interface by querying the + * security policy. The result is added to the network interface table to + * speedup future queries. Returns zero on success, negative values on + * failure. + * + */ +static int sel_netif_sid_slow(struct net *ns, int ifindex, u32 *sid) +{ + int ret = 0; + struct sel_netif *netif; + struct sel_netif *new; + struct net_device *dev; + + /* NOTE: we always use init's network namespace since we don't + * currently support containers */ + + dev = dev_get_by_index(ns, ifindex); + if (unlikely(dev == NULL)) { + pr_warn("SELinux: failure in %s(), invalid network interface (%d)\n", + __func__, ifindex); + return -ENOENT; + } + + spin_lock_bh(&sel_netif_lock); + netif = sel_netif_find(ns, ifindex); + if (netif != NULL) { + *sid = netif->nsec.sid; + goto out; + } + + ret = security_netif_sid(dev->name, sid); + if (ret != 0) + goto out; + + /* If this memory allocation fails still return 0. The SID + * is valid, it just won't be added to the cache. + */ + new = kmalloc_obj(*new, GFP_ATOMIC); + if (new) { + new->nsec.ns = ns; + new->nsec.ifindex = ifindex; + new->nsec.sid = *sid; + if (sel_netif_insert(new)) + kfree(new); + } + +out: + spin_unlock_bh(&sel_netif_lock); + dev_put(dev); + if (unlikely(ret)) + pr_warn("SELinux: failure in %s(), unable to determine network interface label (%d)\n", + __func__, ifindex); + return ret; +} + +/** + * sel_netif_sid - Lookup the SID of a network interface + * @ns: the network namespace + * @ifindex: the network interface + * @sid: interface SID + * + * Description: + * This function determines the SID of a network interface using the fastest + * method possible. First the interface table is queried, but if an entry + * can't be found then the policy is queried and the result is added to the + * table to speedup future queries. Returns zero on success, negative values + * on failure. + * + */ +int sel_netif_sid(struct net *ns, int ifindex, u32 *sid) +{ + struct sel_netif *netif; + + rcu_read_lock(); + netif = sel_netif_find(ns, ifindex); + if (likely(netif != NULL)) { + *sid = netif->nsec.sid; + rcu_read_unlock(); + return 0; + } + rcu_read_unlock(); + + return sel_netif_sid_slow(ns, ifindex, sid); +} + +/** + * sel_netif_kill - Remove an entry from the network interface table + * @ns: the network namespace + * @ifindex: the network interface + * + * Description: + * This function removes the entry matching @ifindex from the network interface + * table if it exists. + * + */ +static void sel_netif_kill(const struct net *ns, int ifindex) +{ + struct sel_netif *netif; + + rcu_read_lock(); + spin_lock_bh(&sel_netif_lock); + netif = sel_netif_find(ns, ifindex); + if (netif) + sel_netif_destroy(netif); + spin_unlock_bh(&sel_netif_lock); + rcu_read_unlock(); +} + +/** + * sel_netif_flush - Flush the entire network interface table + * + * Description: + * Remove all entries from the network interface table. + * + */ +void sel_netif_flush(void) +{ + int idx; + struct sel_netif *netif; + + spin_lock_bh(&sel_netif_lock); + for (idx = 0; idx < SEL_NETIF_HASH_SIZE; idx++) + list_for_each_entry(netif, &sel_netif_hash[idx], list) + sel_netif_destroy(netif); + spin_unlock_bh(&sel_netif_lock); +} + +static int sel_netif_netdev_notifier_handler(struct notifier_block *this, + unsigned long event, void *ptr) +{ + struct net_device *dev = netdev_notifier_info_to_dev(ptr); + + if (event == NETDEV_DOWN) + sel_netif_kill(dev_net(dev), dev->ifindex); + + return NOTIFY_DONE; +} + +static struct notifier_block sel_netif_netdev_notifier = { + .notifier_call = sel_netif_netdev_notifier_handler, +}; + +int __init sel_netif_init(void) +{ + int i; + + if (!selinux_enabled_boot) + return 0; + + for (i = 0; i < SEL_NETIF_HASH_SIZE; i++) + INIT_LIST_HEAD(&sel_netif_hash[i]); + + register_netdevice_notifier(&sel_netif_netdev_notifier); + + return 0; +} + diff --git a/security/selinux/netlabel.c b/security/selinux/netlabel.c new file mode 100644 index 000000000..d51dfe892 --- /dev/null +++ b/security/selinux/netlabel.c @@ -0,0 +1,619 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * SELinux NetLabel Support + * + * This file provides the necessary glue to tie NetLabel into the SELinux + * subsystem. + * + * Author: Paul Moore <paul@paul-moore.com> + */ + +/* + * (c) Copyright Hewlett-Packard Development Company, L.P., 2007, 2008 + */ + +#include <linux/spinlock.h> +#include <linux/rcupdate.h> +#include <linux/gfp.h> +#include <linux/ip.h> +#include <linux/ipv6.h> +#include <linux/lsm_hooks.h> +#include <net/sock.h> +#include <net/netlabel.h> +#include <net/ip.h> +#include <net/ipv6.h> + +#include "objsec.h" +#include "security.h" +#include "netlabel.h" + +/** + * selinux_netlbl_sidlookup_cached - Cache a SID lookup + * @skb: the packet + * @family: the packet's address family + * @secattr: the NetLabel security attributes + * @sid: the SID + * + * Description: + * Query the SELinux security server to lookup the correct SID for the given + * security attributes. If the query is successful, cache the result to speed + * up future lookups. Returns zero on success, negative values on failure. + * + */ +static int selinux_netlbl_sidlookup_cached(struct sk_buff *skb, + u16 family, + struct netlbl_lsm_secattr *secattr, + u32 *sid) +{ + int rc; + + rc = security_netlbl_secattr_to_sid(secattr, sid); + if (rc == 0 && + (secattr->flags & NETLBL_SECATTR_CACHEABLE) && + (secattr->flags & NETLBL_SECATTR_CACHE)) + netlbl_cache_add(skb, family, secattr); + + return rc; +} + +/** + * selinux_netlbl_sock_genattr - Generate the NetLabel socket secattr + * @sk: the socket + * + * Description: + * Generate the NetLabel security attributes for a socket, making full use of + * the socket's attribute cache. Returns a pointer to the security attributes + * on success, or an ERR_PTR on failure. + * + */ +static struct netlbl_lsm_secattr *selinux_netlbl_sock_genattr(struct sock *sk) +{ + int rc; + struct sk_security_struct *sksec = selinux_sock(sk); + struct netlbl_lsm_secattr *secattr; + + if (sksec->nlbl_secattr != NULL) + return sksec->nlbl_secattr; + + secattr = netlbl_secattr_alloc(GFP_ATOMIC); + if (secattr == NULL) + return ERR_PTR(-ENOMEM); + + rc = security_netlbl_sid_to_secattr(sksec->sid, secattr); + if (rc != 0) { + netlbl_secattr_free(secattr); + return ERR_PTR(rc); + } + sksec->nlbl_secattr = secattr; + + return secattr; +} + +/** + * selinux_netlbl_sock_getattr - Get the cached NetLabel secattr + * @sk: the socket + * @sid: the SID + * + * Query the socket's cached secattr and if the SID matches the cached value + * return the cache, otherwise return NULL. + * + */ +static struct netlbl_lsm_secattr *selinux_netlbl_sock_getattr( + const struct sock *sk, + u32 sid) +{ + struct sk_security_struct *sksec = selinux_sock(sk); + struct netlbl_lsm_secattr *secattr = sksec->nlbl_secattr; + + if (secattr == NULL) + return NULL; + + if ((secattr->flags & NETLBL_SECATTR_SECID) && + (secattr->attr.secid == sid)) + return secattr; + + return NULL; +} + +/** + * selinux_netlbl_cache_invalidate - Invalidate the NetLabel cache + * + * Description: + * Invalidate the NetLabel security attribute mapping cache. + * + */ +void selinux_netlbl_cache_invalidate(void) +{ + netlbl_cache_invalidate(); +} + +/** + * selinux_netlbl_err - Handle a NetLabel packet error + * @skb: the packet + * @family: the packet's address family + * @error: the error code + * @gateway: true if host is acting as a gateway, false otherwise + * + * Description: + * When a packet is dropped due to a call to avc_has_perm() pass the error + * code to the NetLabel subsystem so any protocol specific processing can be + * done. This is safe to call even if you are unsure if NetLabel labeling is + * present on the packet, NetLabel is smart enough to only act when it should. + * + */ +void selinux_netlbl_err(struct sk_buff *skb, u16 family, int error, int gateway) +{ + netlbl_skbuff_err(skb, family, error, gateway); +} + +/** + * selinux_netlbl_sk_security_free - Free the NetLabel fields + * @sksec: the sk_security_struct + * + * Description: + * Free all of the memory in the NetLabel fields of a sk_security_struct. + * + */ +void selinux_netlbl_sk_security_free(struct sk_security_struct *sksec) +{ + if (!sksec->nlbl_secattr) + return; + + netlbl_secattr_free(sksec->nlbl_secattr); + sksec->nlbl_secattr = NULL; + sksec->nlbl_state = NLBL_UNSET; +} + +/** + * selinux_netlbl_sk_security_reset - Reset the NetLabel fields + * @sksec: the sk_security_struct + * + * Description: + * Called when the NetLabel state of a sk_security_struct needs to be reset. + * The caller is responsible for all the NetLabel sk_security_struct locking. + * + */ +void selinux_netlbl_sk_security_reset(struct sk_security_struct *sksec) +{ + sksec->nlbl_state = NLBL_UNSET; +} + +/** + * selinux_netlbl_skbuff_getsid - Get the sid of a packet using NetLabel + * @skb: the packet + * @family: protocol family + * @type: NetLabel labeling protocol type + * @sid: the SID + * + * Description: + * Call the NetLabel mechanism to get the security attributes of the given + * packet and use those attributes to determine the correct context/SID to + * assign to the packet. Returns zero on success, negative values on failure. + * + */ +int selinux_netlbl_skbuff_getsid(struct sk_buff *skb, + u16 family, + u32 *type, + u32 *sid) +{ + int rc; + struct netlbl_lsm_secattr secattr; + + if (!netlbl_enabled()) { + *type = NETLBL_NLTYPE_NONE; + *sid = SECSID_NULL; + return 0; + } + + netlbl_secattr_init(&secattr); + rc = netlbl_skbuff_getattr(skb, family, &secattr); + if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE) + rc = selinux_netlbl_sidlookup_cached(skb, family, + &secattr, sid); + else + *sid = SECSID_NULL; + *type = secattr.type; + netlbl_secattr_destroy(&secattr); + + return rc; +} + +/** + * selinux_netlbl_skbuff_setsid - Set the NetLabel on a packet given a sid + * @skb: the packet + * @family: protocol family + * @sid: the SID + * + * Description + * Call the NetLabel mechanism to set the label of a packet using @sid. + * Returns zero on success, negative values on failure. + * + */ +int selinux_netlbl_skbuff_setsid(struct sk_buff *skb, + u16 family, + u32 sid) +{ + int rc; + struct netlbl_lsm_secattr secattr_storage; + struct netlbl_lsm_secattr *secattr = NULL; + struct sock *sk; + + /* if this is a locally generated packet check to see if it is already + * being labeled by it's parent socket, if it is just exit */ + sk = skb_to_full_sk(skb); + if (sk != NULL) { + struct sk_security_struct *sksec = selinux_sock(sk); + + if (sksec->nlbl_state != NLBL_REQSKB) + return 0; + secattr = selinux_netlbl_sock_getattr(sk, sid); + } + if (secattr == NULL) { + secattr = &secattr_storage; + netlbl_secattr_init(secattr); + rc = security_netlbl_sid_to_secattr(sid, secattr); + if (rc != 0) + goto skbuff_setsid_return; + } + + rc = netlbl_skbuff_setattr(skb, family, secattr); + +skbuff_setsid_return: + if (secattr == &secattr_storage) + netlbl_secattr_destroy(secattr); + return rc; +} + +/** + * selinux_netlbl_sctp_assoc_request - Label an incoming sctp association. + * @asoc: incoming association. + * @skb: the packet. + * + * Description: + * A new incoming connection is represented by @asoc, ...... + * Returns zero on success, negative values on failure. + * + */ +int selinux_netlbl_sctp_assoc_request(struct sctp_association *asoc, + struct sk_buff *skb) +{ + int rc; + struct netlbl_lsm_secattr secattr; + struct sk_security_struct *sksec = selinux_sock(asoc->base.sk); + struct sockaddr_in addr4; + struct sockaddr_in6 addr6; + + if (asoc->base.sk->sk_family != PF_INET && + asoc->base.sk->sk_family != PF_INET6) + return 0; + + netlbl_secattr_init(&secattr); + rc = security_netlbl_sid_to_secattr(asoc->secid, &secattr); + if (rc != 0) + goto assoc_request_return; + + /* Move skb hdr address info to a struct sockaddr and then call + * netlbl_conn_setattr(). + */ + if (ip_hdr(skb)->version == 4) { + addr4.sin_family = AF_INET; + addr4.sin_addr.s_addr = ip_hdr(skb)->saddr; + rc = netlbl_conn_setattr(asoc->base.sk, (void *)&addr4, &secattr); + } else if (IS_ENABLED(CONFIG_IPV6) && ip_hdr(skb)->version == 6) { + addr6.sin6_family = AF_INET6; + addr6.sin6_addr = ipv6_hdr(skb)->saddr; + rc = netlbl_conn_setattr(asoc->base.sk, (void *)&addr6, &secattr); + } else { + rc = -EAFNOSUPPORT; + } + + if (rc == 0) + sksec->nlbl_state = NLBL_LABELED; + +assoc_request_return: + netlbl_secattr_destroy(&secattr); + return rc; +} + +/** + * selinux_netlbl_inet_conn_request - Label an incoming stream connection + * @req: incoming connection request socket + * @family: the request socket's address family + * + * Description: + * A new incoming connection request is represented by @req, we need to label + * the new request_sock here and the stack will ensure the on-the-wire label + * will get preserved when a full sock is created once the connection handshake + * is complete. Returns zero on success, negative values on failure. + * + */ +int selinux_netlbl_inet_conn_request(struct request_sock *req, u16 family) +{ + int rc; + struct netlbl_lsm_secattr secattr; + + if (family != PF_INET && family != PF_INET6) + return 0; + + netlbl_secattr_init(&secattr); + rc = security_netlbl_sid_to_secattr(req->secid, &secattr); + if (rc != 0) + goto inet_conn_request_return; + rc = netlbl_req_setattr(req, &secattr); +inet_conn_request_return: + netlbl_secattr_destroy(&secattr); + return rc; +} + +/** + * selinux_netlbl_inet_csk_clone - Initialize the newly created sock + * @sk: the new sock + * @family: the sock's address family + * + * Description: + * A new connection has been established using @sk, we've already labeled the + * socket via the request_sock struct in selinux_netlbl_inet_conn_request() but + * we need to set the NetLabel state here since we now have a sock structure. + * + */ +void selinux_netlbl_inet_csk_clone(struct sock *sk, u16 family) +{ + struct sk_security_struct *sksec = selinux_sock(sk); + + if (family == PF_INET || family == PF_INET6) + sksec->nlbl_state = NLBL_LABELED; + else + sksec->nlbl_state = NLBL_UNSET; +} + +/** + * selinux_netlbl_sctp_sk_clone - Copy state to the newly created sock + * @sk: current sock + * @newsk: the new sock + * + * Description: + * Called whenever a new socket is created by accept(2) or sctp_peeloff(3). + */ +void selinux_netlbl_sctp_sk_clone(struct sock *sk, struct sock *newsk) +{ + struct sk_security_struct *sksec = selinux_sock(sk); + struct sk_security_struct *newsksec = selinux_sock(newsk); + + newsksec->nlbl_state = sksec->nlbl_state; +} + +/** + * selinux_netlbl_socket_post_create - Label a socket using NetLabel + * @sk: the sock to label + * @family: protocol family + * + * Description: + * Attempt to label a socket using the NetLabel mechanism using the given + * SID. Returns zero values on success, negative values on failure. + * + */ +int selinux_netlbl_socket_post_create(struct sock *sk, u16 family) +{ + int rc; + struct sk_security_struct *sksec = selinux_sock(sk); + struct netlbl_lsm_secattr *secattr; + + if (family != PF_INET && family != PF_INET6) + return 0; + + secattr = selinux_netlbl_sock_genattr(sk); + if (IS_ERR(secattr)) + return PTR_ERR(secattr); + /* On socket creation, replacement of IP options is safe even if + * the caller does not hold the socket lock. + */ + rc = netlbl_sock_setattr(sk, family, secattr, true); + switch (rc) { + case 0: + sksec->nlbl_state = NLBL_LABELED; + break; + case -EDESTADDRREQ: + sksec->nlbl_state = NLBL_REQSKB; + rc = 0; + break; + } + + return rc; +} + +/** + * selinux_netlbl_sock_rcv_skb - Do an inbound access check using NetLabel + * @sksec: the sock's sk_security_struct + * @skb: the packet + * @family: protocol family + * @ad: the audit data + * + * Description: + * Fetch the NetLabel security attributes from @skb and perform an access check + * against the receiving socket. Returns zero on success, negative values on + * error. + * + */ +int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec, + struct sk_buff *skb, + u16 family, + struct common_audit_data *ad) +{ + int rc; + u32 nlbl_sid; + u32 perm; + struct netlbl_lsm_secattr secattr; + + if (!netlbl_enabled()) + return 0; + + netlbl_secattr_init(&secattr); + rc = netlbl_skbuff_getattr(skb, family, &secattr); + if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE) + rc = selinux_netlbl_sidlookup_cached(skb, family, + &secattr, &nlbl_sid); + else + nlbl_sid = SECINITSID_UNLABELED; + netlbl_secattr_destroy(&secattr); + if (rc != 0) + return rc; + + switch (sksec->sclass) { + case SECCLASS_UDP_SOCKET: + perm = UDP_SOCKET__RECVFROM; + break; + case SECCLASS_TCP_SOCKET: + perm = TCP_SOCKET__RECVFROM; + break; + default: + perm = RAWIP_SOCKET__RECVFROM; + } + + rc = avc_has_perm(sksec->sid, nlbl_sid, sksec->sclass, perm, ad); + if (rc == 0) + return 0; + + if (nlbl_sid != SECINITSID_UNLABELED) + netlbl_skbuff_err(skb, family, rc, 0); + return rc; +} + +/** + * selinux_netlbl_option - Is this a NetLabel option + * @level: the socket level or protocol + * @optname: the socket option name + * + * Description: + * Returns true if @level and @optname refer to a NetLabel option. + * Helper for selinux_netlbl_socket_setsockopt(). + */ +static inline int selinux_netlbl_option(int level, int optname) +{ + return (level == IPPROTO_IP && optname == IP_OPTIONS) || + (level == IPPROTO_IPV6 && optname == IPV6_HOPOPTS); +} + +/** + * selinux_netlbl_socket_setsockopt - Do not allow users to remove a NetLabel + * @sock: the socket + * @level: the socket level or protocol + * @optname: the socket option name + * + * Description: + * Check the setsockopt() call and if the user is trying to replace the IP + * options on a socket and a NetLabel is in place for the socket deny the + * access; otherwise allow the access. Returns zero when the access is + * allowed, -EACCES when denied, and other negative values on error. + * + */ +int selinux_netlbl_socket_setsockopt(struct socket *sock, + int level, + int optname) +{ + int rc = 0; + struct sock *sk = sock->sk; + struct sk_security_struct *sksec = selinux_sock(sk); + struct netlbl_lsm_secattr secattr; + + if (selinux_netlbl_option(level, optname) && + (sksec->nlbl_state == NLBL_LABELED || + sksec->nlbl_state == NLBL_CONNLABELED)) { + netlbl_secattr_init(&secattr); + lock_sock(sk); + /* call the netlabel function directly as we want to see the + * on-the-wire label that is assigned via the socket's options + * and not the cached netlabel/lsm attributes */ + rc = netlbl_sock_getattr(sk, &secattr); + release_sock(sk); + if (rc == 0) + rc = -EACCES; + else if (rc == -ENOMSG) + rc = 0; + netlbl_secattr_destroy(&secattr); + } + + return rc; +} + +/** + * selinux_netlbl_socket_connect_helper - Help label a client-side socket on + * connect + * @sk: the socket to label + * @addr: the destination address + * + * Description: + * Attempt to label a connected socket with NetLabel using the given address. + * Returns zero values on success, negative values on failure. + * + */ +static int selinux_netlbl_socket_connect_helper(struct sock *sk, + struct sockaddr *addr) +{ + int rc; + struct sk_security_struct *sksec = selinux_sock(sk); + struct netlbl_lsm_secattr *secattr; + + /* connected sockets are allowed to disconnect when the address family + * is set to AF_UNSPEC, if that is what is happening we want to reset + * the socket */ + if (addr->sa_family == AF_UNSPEC) { + netlbl_sock_delattr(sk); + sksec->nlbl_state = NLBL_REQSKB; + rc = 0; + return rc; + } + secattr = selinux_netlbl_sock_genattr(sk); + if (IS_ERR(secattr)) + return PTR_ERR(secattr); + + rc = netlbl_conn_setattr(sk, addr, secattr); + if (rc == 0) + sksec->nlbl_state = NLBL_CONNLABELED; + + return rc; +} + +/** + * selinux_netlbl_socket_connect_locked - Label a client-side socket on + * connect + * @sk: the socket to label + * @addr: the destination address + * + * Description: + * Attempt to label a connected socket that already has the socket locked + * with NetLabel using the given address. + * Returns zero values on success, negative values on failure. + * + */ +int selinux_netlbl_socket_connect_locked(struct sock *sk, + struct sockaddr *addr) +{ + struct sk_security_struct *sksec = selinux_sock(sk); + + if (sksec->nlbl_state != NLBL_REQSKB && + sksec->nlbl_state != NLBL_CONNLABELED) + return 0; + + return selinux_netlbl_socket_connect_helper(sk, addr); +} + +/** + * selinux_netlbl_socket_connect - Label a client-side socket on connect + * @sk: the socket to label + * @addr: the destination address + * + * Description: + * Attempt to label a connected socket with NetLabel using the given address. + * Returns zero values on success, negative values on failure. + * + */ +int selinux_netlbl_socket_connect(struct sock *sk, struct sockaddr *addr) +{ + int rc; + + lock_sock(sk); + rc = selinux_netlbl_socket_connect_locked(sk, addr); + release_sock(sk); + + return rc; +} diff --git a/security/selinux/netlink.c b/security/selinux/netlink.c new file mode 100644 index 000000000..eb40e4603 --- /dev/null +++ b/security/selinux/netlink.c @@ -0,0 +1,120 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Netlink event notifications for SELinux. + * + * Author: James Morris <jmorris@redhat.com> + * + * Copyright (C) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com> + */ +#include <linux/init.h> +#include <linux/types.h> +#include <linux/slab.h> +#include <linux/stddef.h> +#include <linux/kernel.h> +#include <linux/export.h> +#include <linux/skbuff.h> +#include <linux/selinux_netlink.h> +#include <net/net_namespace.h> +#include <net/netlink.h> + +#include "initcalls.h" +#include "security.h" + +static struct sock *selnl __ro_after_init; + +static int selnl_msglen(int msgtype) +{ + int ret = 0; + + switch (msgtype) { + case SELNL_MSG_SETENFORCE: + ret = sizeof(struct selnl_msg_setenforce); + break; + + case SELNL_MSG_POLICYLOAD: + ret = sizeof(struct selnl_msg_policyload); + break; + + default: + BUG(); + } + return ret; +} + +static void selnl_add_payload(struct nlmsghdr *nlh, int len, int msgtype, void *data) +{ + switch (msgtype) { + case SELNL_MSG_SETENFORCE: { + struct selnl_msg_setenforce *msg = nlmsg_data(nlh); + + memset(msg, 0, len); + msg->val = *((int *)data); + break; + } + + case SELNL_MSG_POLICYLOAD: { + struct selnl_msg_policyload *msg = nlmsg_data(nlh); + + memset(msg, 0, len); + msg->seqno = *((u32 *)data); + break; + } + + default: + BUG(); + } +} + +static void selnl_notify(int msgtype, void *data) +{ + int len; + sk_buff_data_t tmp; + struct sk_buff *skb; + struct nlmsghdr *nlh; + + len = selnl_msglen(msgtype); + + skb = nlmsg_new(len, GFP_USER); + if (!skb) + goto oom; + + tmp = skb->tail; + nlh = nlmsg_put(skb, 0, 0, msgtype, len, 0); + if (!nlh) + goto out_kfree_skb; + selnl_add_payload(nlh, len, msgtype, data); + nlh->nlmsg_len = skb->tail - tmp; + NETLINK_CB(skb).dst_group = SELNLGRP_AVC; + netlink_broadcast(selnl, skb, 0, SELNLGRP_AVC, GFP_USER); +out: + return; + +out_kfree_skb: + kfree_skb(skb); +oom: + pr_err("SELinux: OOM in %s\n", __func__); + goto out; +} + +void selnl_notify_setenforce(int val) +{ + selnl_notify(SELNL_MSG_SETENFORCE, &val); +} + +void selnl_notify_policyload(u32 seqno) +{ + selnl_notify(SELNL_MSG_POLICYLOAD, &seqno); +} + +int __init sel_netlink_init(void) +{ + struct netlink_kernel_cfg cfg = { + .groups = SELNLGRP_MAX, + .flags = NL_CFG_F_NONROOT_RECV, + }; + + selnl = netlink_kernel_create(&init_net, NETLINK_SELINUX, &cfg); + if (selnl == NULL) + panic("SELinux: Cannot create netlink socket."); + return 0; +} diff --git a/security/selinux/netnode.c b/security/selinux/netnode.c new file mode 100644 index 000000000..adb93003b --- /dev/null +++ b/security/selinux/netnode.c @@ -0,0 +1,307 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Network node table + * + * SELinux must keep a mapping of network nodes to labels/SIDs. This + * mapping is maintained as part of the normal policy but a fast cache is + * needed to reduce the lookup overhead since most of these queries happen on + * a per-packet basis. + * + * Author: Paul Moore <paul@paul-moore.com> + * + * This code is heavily based on the "netif" concept originally developed by + * James Morris <jmorris@redhat.com> + * (see security/selinux/netif.c for more information) + */ + +/* + * (c) Copyright Hewlett-Packard Development Company, L.P., 2007 + */ + +#include <linux/types.h> +#include <linux/rcupdate.h> +#include <linux/list.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/in.h> +#include <linux/in6.h> +#include <linux/ip.h> +#include <linux/ipv6.h> +#include <net/ip.h> +#include <net/ipv6.h> + +#include "initcalls.h" +#include "netnode.h" +#include "objsec.h" + +#define SEL_NETNODE_HASH_SIZE 256 +#define SEL_NETNODE_HASH_BKT_LIMIT 16 + +struct sel_netnode_bkt { + unsigned int size; + struct list_head list; +}; + +struct sel_netnode { + struct netnode_security_struct nsec; + + struct list_head list; + struct rcu_head rcu; +}; + +/* NOTE: we are using a combined hash table for both IPv4 and IPv6, the reason + * for this is that I suspect most users will not make heavy use of both + * address families at the same time so one table will usually end up wasted, + * if this becomes a problem we can always add a hash table for each address + * family later */ + +static DEFINE_SPINLOCK(sel_netnode_lock); +static struct sel_netnode_bkt sel_netnode_hash[SEL_NETNODE_HASH_SIZE]; + +/** + * sel_netnode_hashfn_ipv4 - IPv4 hashing function for the node table + * @addr: IPv4 address + * + * Description: + * This is the IPv4 hashing function for the node interface table, it returns + * the bucket number for the given IP address. + * + */ +static unsigned int sel_netnode_hashfn_ipv4(__be32 addr) +{ + /* at some point we should determine if the mismatch in byte order + * affects the hash function dramatically */ + return (addr & (SEL_NETNODE_HASH_SIZE - 1)); +} + +/** + * sel_netnode_hashfn_ipv6 - IPv6 hashing function for the node table + * @addr: IPv6 address + * + * Description: + * This is the IPv6 hashing function for the node interface table, it returns + * the bucket number for the given IP address. + * + */ +static unsigned int sel_netnode_hashfn_ipv6(const struct in6_addr *addr) +{ + /* just hash the least significant 32 bits to keep things fast (they + * are the most likely to be different anyway), we can revisit this + * later if needed */ + return (addr->s6_addr32[3] & (SEL_NETNODE_HASH_SIZE - 1)); +} + +/** + * sel_netnode_find - Search for a node record + * @addr: IP address + * @family: address family + * + * Description: + * Search the network node table and return the record matching @addr. If an + * entry can not be found in the table return NULL. + * + */ +static struct sel_netnode *sel_netnode_find(const void *addr, u16 family) +{ + unsigned int idx; + struct sel_netnode *node; + + switch (family) { + case PF_INET: + idx = sel_netnode_hashfn_ipv4(*(const __be32 *)addr); + break; + case PF_INET6: + idx = sel_netnode_hashfn_ipv6(addr); + break; + default: + BUG(); + return NULL; + } + + list_for_each_entry_rcu(node, &sel_netnode_hash[idx].list, list) + if (node->nsec.family == family) + switch (family) { + case PF_INET: + if (node->nsec.addr.ipv4 == *(const __be32 *)addr) + return node; + break; + case PF_INET6: + if (ipv6_addr_equal(&node->nsec.addr.ipv6, + addr)) + return node; + break; + } + + return NULL; +} + +/** + * sel_netnode_insert - Insert a new node into the table + * @node: the new node record + * + * Description: + * Add a new node record to the network address hash table. + * + */ +static void sel_netnode_insert(struct sel_netnode *node) +{ + unsigned int idx; + + switch (node->nsec.family) { + case PF_INET: + idx = sel_netnode_hashfn_ipv4(node->nsec.addr.ipv4); + break; + case PF_INET6: + idx = sel_netnode_hashfn_ipv6(&node->nsec.addr.ipv6); + break; + default: + BUG(); + return; + } + + /* we need to impose a limit on the growth of the hash table so check + * this bucket to make sure it is within the specified bounds */ + list_add_rcu(&node->list, &sel_netnode_hash[idx].list); + if (sel_netnode_hash[idx].size == SEL_NETNODE_HASH_BKT_LIMIT) { + struct sel_netnode *tail; + tail = list_entry( + rcu_dereference_protected( + list_tail_rcu(&sel_netnode_hash[idx].list), + lockdep_is_held(&sel_netnode_lock)), + struct sel_netnode, list); + list_del_rcu(&tail->list); + kfree_rcu(tail, rcu); + } else + sel_netnode_hash[idx].size++; +} + +/** + * sel_netnode_sid_slow - Lookup the SID of a network address using the policy + * @addr: the IP address + * @family: the address family + * @sid: node SID + * + * Description: + * This function determines the SID of a network address by querying the + * security policy. The result is added to the network address table to + * speedup future queries. Returns zero on success, negative values on + * failure. + * + */ +static int sel_netnode_sid_slow(const void *addr, u16 family, u32 *sid) +{ + int ret; + struct sel_netnode *node; + struct sel_netnode *new; + + spin_lock_bh(&sel_netnode_lock); + node = sel_netnode_find(addr, family); + if (node != NULL) { + *sid = node->nsec.sid; + spin_unlock_bh(&sel_netnode_lock); + return 0; + } + + /* If this memory allocation fails still return 0. The SID + * is valid, it just won't be added to the cache. + */ + new = kmalloc_obj(*new, GFP_ATOMIC); + switch (family) { + case PF_INET: + ret = security_node_sid(PF_INET, + addr, sizeof(struct in_addr), sid); + if (new) + new->nsec.addr.ipv4 = *(const __be32 *)addr; + break; + case PF_INET6: + ret = security_node_sid(PF_INET6, + addr, sizeof(struct in6_addr), sid); + if (new) + new->nsec.addr.ipv6 = *(const struct in6_addr *)addr; + break; + default: + BUG(); + ret = -EINVAL; + } + if (ret == 0 && new) { + new->nsec.family = family; + new->nsec.sid = *sid; + sel_netnode_insert(new); + } else + kfree(new); + + spin_unlock_bh(&sel_netnode_lock); + if (unlikely(ret)) + pr_warn("SELinux: failure in %s(), unable to determine network node label\n", + __func__); + return ret; +} + +/** + * sel_netnode_sid - Lookup the SID of a network address + * @addr: the IP address + * @family: the address family + * @sid: node SID + * + * Description: + * This function determines the SID of a network address using the fastest + * method possible. First the address table is queried, but if an entry + * can't be found then the policy is queried and the result is added to the + * table to speedup future queries. Returns zero on success, negative values + * on failure. + * + */ +int sel_netnode_sid(const void *addr, u16 family, u32 *sid) +{ + struct sel_netnode *node; + + rcu_read_lock(); + node = sel_netnode_find(addr, family); + if (likely(node != NULL)) { + *sid = node->nsec.sid; + rcu_read_unlock(); + return 0; + } + rcu_read_unlock(); + + return sel_netnode_sid_slow(addr, family, sid); +} + +/** + * sel_netnode_flush - Flush the entire network address table + * + * Description: + * Remove all entries from the network address table. + * + */ +void sel_netnode_flush(void) +{ + unsigned int idx; + struct sel_netnode *node, *node_tmp; + + spin_lock_bh(&sel_netnode_lock); + for (idx = 0; idx < SEL_NETNODE_HASH_SIZE; idx++) { + list_for_each_entry_safe(node, node_tmp, + &sel_netnode_hash[idx].list, list) { + list_del_rcu(&node->list); + kfree_rcu(node, rcu); + } + sel_netnode_hash[idx].size = 0; + } + spin_unlock_bh(&sel_netnode_lock); +} + +int __init sel_netnode_init(void) +{ + int iter; + + if (!selinux_enabled_boot) + return 0; + + for (iter = 0; iter < SEL_NETNODE_HASH_SIZE; iter++) { + INIT_LIST_HEAD(&sel_netnode_hash[iter].list); + sel_netnode_hash[iter].size = 0; + } + + return 0; +} diff --git a/security/selinux/netport.c b/security/selinux/netport.c new file mode 100644 index 000000000..006a6ec71 --- /dev/null +++ b/security/selinux/netport.c @@ -0,0 +1,235 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Network port table + * + * SELinux must keep a mapping of network ports to labels/SIDs. This + * mapping is maintained as part of the normal policy but a fast cache is + * needed to reduce the lookup overhead. + * + * Author: Paul Moore <paul@paul-moore.com> + * + * This code is heavily based on the "netif" concept originally developed by + * James Morris <jmorris@redhat.com> + * (see security/selinux/netif.c for more information) + */ + +/* + * (c) Copyright Hewlett-Packard Development Company, L.P., 2008 + */ + +#include <linux/types.h> +#include <linux/rcupdate.h> +#include <linux/list.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/in.h> +#include <linux/in6.h> +#include <linux/ip.h> +#include <linux/ipv6.h> +#include <net/ip.h> +#include <net/ipv6.h> + +#include "initcalls.h" +#include "netport.h" +#include "objsec.h" + +#define SEL_NETPORT_HASH_SIZE 256 +#define SEL_NETPORT_HASH_BKT_LIMIT 16 + +struct sel_netport_bkt { + int size; + struct list_head list; +}; + +struct sel_netport { + struct netport_security_struct psec; + + struct list_head list; + struct rcu_head rcu; +}; + +static DEFINE_SPINLOCK(sel_netport_lock); +static struct sel_netport_bkt sel_netport_hash[SEL_NETPORT_HASH_SIZE]; + +/** + * sel_netport_hashfn - Hashing function for the port table + * @pnum: port number + * + * Description: + * This is the hashing function for the port table, it returns the bucket + * number for the given port. + * + */ +static unsigned int sel_netport_hashfn(u16 pnum) +{ + return (pnum & (SEL_NETPORT_HASH_SIZE - 1)); +} + +/** + * sel_netport_find - Search for a port record + * @protocol: protocol + * @pnum: port + * + * Description: + * Search the network port table and return the matching record. If an entry + * can not be found in the table return NULL. + * + */ +static struct sel_netport *sel_netport_find(u8 protocol, u16 pnum) +{ + unsigned int idx; + struct sel_netport *port; + + idx = sel_netport_hashfn(pnum); + list_for_each_entry_rcu(port, &sel_netport_hash[idx].list, list) + if (port->psec.port == pnum && port->psec.protocol == protocol) + return port; + + return NULL; +} + +/** + * sel_netport_insert - Insert a new port into the table + * @port: the new port record + * + * Description: + * Add a new port record to the network address hash table. + * + */ +static void sel_netport_insert(struct sel_netport *port) +{ + unsigned int idx; + + /* we need to impose a limit on the growth of the hash table so check + * this bucket to make sure it is within the specified bounds */ + idx = sel_netport_hashfn(port->psec.port); + list_add_rcu(&port->list, &sel_netport_hash[idx].list); + if (sel_netport_hash[idx].size == SEL_NETPORT_HASH_BKT_LIMIT) { + struct sel_netport *tail; + tail = list_entry( + rcu_dereference_protected( + list_tail_rcu(&sel_netport_hash[idx].list), + lockdep_is_held(&sel_netport_lock)), + struct sel_netport, list); + list_del_rcu(&tail->list); + kfree_rcu(tail, rcu); + } else + sel_netport_hash[idx].size++; +} + +/** + * sel_netport_sid_slow - Lookup the SID of a network address using the policy + * @protocol: protocol + * @pnum: port + * @sid: port SID + * + * Description: + * This function determines the SID of a network port by querying the security + * policy. The result is added to the network port table to speedup future + * queries. Returns zero on success, negative values on failure. + * + */ +static int sel_netport_sid_slow(u8 protocol, u16 pnum, u32 *sid) +{ + int ret; + struct sel_netport *port; + struct sel_netport *new; + + spin_lock_bh(&sel_netport_lock); + port = sel_netport_find(protocol, pnum); + if (port != NULL) { + *sid = port->psec.sid; + spin_unlock_bh(&sel_netport_lock); + return 0; + } + + ret = security_port_sid(protocol, pnum, sid); + if (ret != 0) + goto out; + + /* If this memory allocation fails still return 0. The SID + * is valid, it just won't be added to the cache. + */ + new = kmalloc_obj(*new, GFP_ATOMIC); + if (new) { + new->psec.port = pnum; + new->psec.protocol = protocol; + new->psec.sid = *sid; + sel_netport_insert(new); + } + +out: + spin_unlock_bh(&sel_netport_lock); + if (unlikely(ret)) + pr_warn("SELinux: failure in %s(), unable to determine network port label\n", + __func__); + return ret; +} + +/** + * sel_netport_sid - Lookup the SID of a network port + * @protocol: protocol + * @pnum: port + * @sid: port SID + * + * Description: + * This function determines the SID of a network port using the fastest method + * possible. First the port table is queried, but if an entry can't be found + * then the policy is queried and the result is added to the table to speedup + * future queries. Returns zero on success, negative values on failure. + * + */ +int sel_netport_sid(u8 protocol, u16 pnum, u32 *sid) +{ + struct sel_netport *port; + + rcu_read_lock(); + port = sel_netport_find(protocol, pnum); + if (likely(port != NULL)) { + *sid = port->psec.sid; + rcu_read_unlock(); + return 0; + } + rcu_read_unlock(); + + return sel_netport_sid_slow(protocol, pnum, sid); +} + +/** + * sel_netport_flush - Flush the entire network port table + * + * Description: + * Remove all entries from the network address table. + * + */ +void sel_netport_flush(void) +{ + unsigned int idx; + struct sel_netport *port, *port_tmp; + + spin_lock_bh(&sel_netport_lock); + for (idx = 0; idx < SEL_NETPORT_HASH_SIZE; idx++) { + list_for_each_entry_safe(port, port_tmp, + &sel_netport_hash[idx].list, list) { + list_del_rcu(&port->list); + kfree_rcu(port, rcu); + } + sel_netport_hash[idx].size = 0; + } + spin_unlock_bh(&sel_netport_lock); +} + +int __init sel_netport_init(void) +{ + int iter; + + if (!selinux_enabled_boot) + return 0; + + for (iter = 0; iter < SEL_NETPORT_HASH_SIZE; iter++) { + INIT_LIST_HEAD(&sel_netport_hash[iter].list); + sel_netport_hash[iter].size = 0; + } + + return 0; +} diff --git a/security/selinux/nlmsgtab.c b/security/selinux/nlmsgtab.c new file mode 100644 index 000000000..655d2616c --- /dev/null +++ b/security/selinux/nlmsgtab.c @@ -0,0 +1,234 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Netlink message type permission tables, for user generated messages. + * + * Author: James Morris <jmorris@redhat.com> + * + * Copyright (C) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com> + */ +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/netlink.h> +#include <linux/rtnetlink.h> +#include <linux/if.h> +#include <linux/inet_diag.h> +#include <linux/xfrm.h> +#include <linux/audit.h> +#include <linux/sock_diag.h> + +#include "flask.h" +#include "av_permissions.h" +#include "security.h" + +struct nlmsg_perm { + u16 nlmsg_type; + u32 perm; +}; + +static const struct nlmsg_perm nlmsg_route_perms[] = { + { RTM_NEWLINK, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_DELLINK, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_GETLINK, NETLINK_ROUTE_SOCKET__NLMSG_READ }, + { RTM_SETLINK, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_NEWADDR, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_DELADDR, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_GETADDR, NETLINK_ROUTE_SOCKET__NLMSG_READ }, + { RTM_NEWROUTE, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_DELROUTE, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_GETROUTE, NETLINK_ROUTE_SOCKET__NLMSG_READ }, + { RTM_NEWNEIGH, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_DELNEIGH, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_GETNEIGH, NETLINK_ROUTE_SOCKET__NLMSG_READ }, + { RTM_NEWRULE, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_DELRULE, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_GETRULE, NETLINK_ROUTE_SOCKET__NLMSG_READ }, + { RTM_NEWQDISC, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_DELQDISC, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_GETQDISC, NETLINK_ROUTE_SOCKET__NLMSG_READ }, + { RTM_NEWTCLASS, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_DELTCLASS, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_GETTCLASS, NETLINK_ROUTE_SOCKET__NLMSG_READ }, + { RTM_NEWTFILTER, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_DELTFILTER, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_GETTFILTER, NETLINK_ROUTE_SOCKET__NLMSG_READ }, + { RTM_NEWACTION, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_DELACTION, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_GETACTION, NETLINK_ROUTE_SOCKET__NLMSG_READ }, + { RTM_NEWPREFIX, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_GETMULTICAST, NETLINK_ROUTE_SOCKET__NLMSG_READ }, + { RTM_GETANYCAST, NETLINK_ROUTE_SOCKET__NLMSG_READ }, + { RTM_GETNEIGHTBL, NETLINK_ROUTE_SOCKET__NLMSG_READ }, + { RTM_SETNEIGHTBL, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_NEWADDRLABEL, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_DELADDRLABEL, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_GETADDRLABEL, NETLINK_ROUTE_SOCKET__NLMSG_READ }, + { RTM_GETDCB, NETLINK_ROUTE_SOCKET__NLMSG_READ }, + { RTM_SETDCB, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_NEWNETCONF, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_DELNETCONF, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_GETNETCONF, NETLINK_ROUTE_SOCKET__NLMSG_READ }, + { RTM_NEWMDB, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_DELMDB, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_GETMDB, NETLINK_ROUTE_SOCKET__NLMSG_READ }, + { RTM_NEWNSID, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_DELNSID, NETLINK_ROUTE_SOCKET__NLMSG_READ }, + { RTM_GETNSID, NETLINK_ROUTE_SOCKET__NLMSG_READ }, + { RTM_NEWSTATS, NETLINK_ROUTE_SOCKET__NLMSG_READ }, + { RTM_GETSTATS, NETLINK_ROUTE_SOCKET__NLMSG_READ }, + { RTM_SETSTATS, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_NEWCACHEREPORT, NETLINK_ROUTE_SOCKET__NLMSG_READ }, + { RTM_NEWCHAIN, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_DELCHAIN, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_GETCHAIN, NETLINK_ROUTE_SOCKET__NLMSG_READ }, + { RTM_NEWNEXTHOP, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_DELNEXTHOP, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_GETNEXTHOP, NETLINK_ROUTE_SOCKET__NLMSG_READ }, + { RTM_NEWLINKPROP, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_DELLINKPROP, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_NEWVLAN, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_DELVLAN, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_GETVLAN, NETLINK_ROUTE_SOCKET__NLMSG_READ }, + { RTM_NEWNEXTHOPBUCKET, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_DELNEXTHOPBUCKET, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_GETNEXTHOPBUCKET, NETLINK_ROUTE_SOCKET__NLMSG_READ }, + { RTM_NEWTUNNEL, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_DELTUNNEL, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_GETTUNNEL, NETLINK_ROUTE_SOCKET__NLMSG_READ }, +}; + +static const struct nlmsg_perm nlmsg_tcpdiag_perms[] = { + { TCPDIAG_GETSOCK, NETLINK_TCPDIAG_SOCKET__NLMSG_READ }, + { SOCK_DIAG_BY_FAMILY, NETLINK_TCPDIAG_SOCKET__NLMSG_READ }, + { SOCK_DESTROY, NETLINK_TCPDIAG_SOCKET__NLMSG_WRITE }, +}; + +static const struct nlmsg_perm nlmsg_xfrm_perms[] = { + { XFRM_MSG_NEWSA, NETLINK_XFRM_SOCKET__NLMSG_WRITE }, + { XFRM_MSG_DELSA, NETLINK_XFRM_SOCKET__NLMSG_WRITE }, + { XFRM_MSG_GETSA, NETLINK_XFRM_SOCKET__NLMSG_READ }, + { XFRM_MSG_NEWPOLICY, NETLINK_XFRM_SOCKET__NLMSG_WRITE }, + { XFRM_MSG_DELPOLICY, NETLINK_XFRM_SOCKET__NLMSG_WRITE }, + { XFRM_MSG_GETPOLICY, NETLINK_XFRM_SOCKET__NLMSG_READ }, + { XFRM_MSG_ALLOCSPI, NETLINK_XFRM_SOCKET__NLMSG_WRITE }, + { XFRM_MSG_ACQUIRE, NETLINK_XFRM_SOCKET__NLMSG_WRITE }, + { XFRM_MSG_EXPIRE, NETLINK_XFRM_SOCKET__NLMSG_WRITE }, + { XFRM_MSG_UPDPOLICY, NETLINK_XFRM_SOCKET__NLMSG_WRITE }, + { XFRM_MSG_UPDSA, NETLINK_XFRM_SOCKET__NLMSG_WRITE }, + { XFRM_MSG_POLEXPIRE, NETLINK_XFRM_SOCKET__NLMSG_WRITE }, + { XFRM_MSG_FLUSHSA, NETLINK_XFRM_SOCKET__NLMSG_WRITE }, + { XFRM_MSG_FLUSHPOLICY, NETLINK_XFRM_SOCKET__NLMSG_WRITE }, + { XFRM_MSG_NEWAE, NETLINK_XFRM_SOCKET__NLMSG_WRITE }, + { XFRM_MSG_GETAE, NETLINK_XFRM_SOCKET__NLMSG_READ }, + { XFRM_MSG_REPORT, NETLINK_XFRM_SOCKET__NLMSG_READ }, + { XFRM_MSG_MIGRATE, NETLINK_XFRM_SOCKET__NLMSG_WRITE }, + { XFRM_MSG_NEWSADINFO, NETLINK_XFRM_SOCKET__NLMSG_READ }, + { XFRM_MSG_GETSADINFO, NETLINK_XFRM_SOCKET__NLMSG_READ }, + { XFRM_MSG_NEWSPDINFO, NETLINK_XFRM_SOCKET__NLMSG_WRITE }, + { XFRM_MSG_GETSPDINFO, NETLINK_XFRM_SOCKET__NLMSG_READ }, + { XFRM_MSG_MAPPING, NETLINK_XFRM_SOCKET__NLMSG_READ }, + { XFRM_MSG_SETDEFAULT, NETLINK_XFRM_SOCKET__NLMSG_WRITE }, + { XFRM_MSG_GETDEFAULT, NETLINK_XFRM_SOCKET__NLMSG_READ }, + { XFRM_MSG_MIGRATE_STATE, NETLINK_XFRM_SOCKET__NLMSG_WRITE }, +}; + +static const struct nlmsg_perm nlmsg_audit_perms[] = { + { AUDIT_GET, NETLINK_AUDIT_SOCKET__NLMSG_READ }, + { AUDIT_SET, NETLINK_AUDIT_SOCKET__NLMSG_WRITE }, + { AUDIT_LIST, NETLINK_AUDIT_SOCKET__NLMSG_READPRIV }, + { AUDIT_ADD, NETLINK_AUDIT_SOCKET__NLMSG_WRITE }, + { AUDIT_DEL, NETLINK_AUDIT_SOCKET__NLMSG_WRITE }, + { AUDIT_LIST_RULES, NETLINK_AUDIT_SOCKET__NLMSG_READPRIV }, + { AUDIT_ADD_RULE, NETLINK_AUDIT_SOCKET__NLMSG_WRITE }, + { AUDIT_DEL_RULE, NETLINK_AUDIT_SOCKET__NLMSG_WRITE }, + { AUDIT_USER, NETLINK_AUDIT_SOCKET__NLMSG_RELAY }, + { AUDIT_SIGNAL_INFO, NETLINK_AUDIT_SOCKET__NLMSG_READ }, + { AUDIT_TRIM, NETLINK_AUDIT_SOCKET__NLMSG_WRITE }, + { AUDIT_MAKE_EQUIV, NETLINK_AUDIT_SOCKET__NLMSG_WRITE }, + { AUDIT_TTY_GET, NETLINK_AUDIT_SOCKET__NLMSG_READ }, + { AUDIT_TTY_SET, NETLINK_AUDIT_SOCKET__NLMSG_TTY_AUDIT }, + { AUDIT_GET_FEATURE, NETLINK_AUDIT_SOCKET__NLMSG_READ }, + { AUDIT_SET_FEATURE, NETLINK_AUDIT_SOCKET__NLMSG_WRITE }, +}; + +static int nlmsg_perm(u16 nlmsg_type, u32 *perm, const struct nlmsg_perm *tab, + size_t tabsize) +{ + unsigned int i; + int err = -EINVAL; + + for (i = 0; i < tabsize / sizeof(struct nlmsg_perm); i++) + if (nlmsg_type == tab[i].nlmsg_type) { + *perm = tab[i].perm; + err = 0; + break; + } + + return err; +} + +int selinux_nlmsg_lookup(u16 sclass, u16 nlmsg_type, u32 *perm) +{ + /* While it is possible to add a similar permission to other netlink + * classes, note that the extended permission value is matched against + * the nlmsg_type field. Notably, SECCLASS_NETLINK_GENERIC_SOCKET uses + * dynamic values for this field, which means that it cannot be added + * as-is. + */ + + switch (sclass) { + case SECCLASS_NETLINK_ROUTE_SOCKET: + /* RTM_MAX always points to RTM_SETxxxx, ie RTM_NEWxxx + 3. + * If the BUILD_BUG_ON() below fails you must update the + * structures at the top of this file with the new mappings + * before updating the BUILD_BUG_ON() macro! + */ + BUILD_BUG_ON(RTM_MAX != (RTM_NEWTUNNEL + 3)); + + if (selinux_policycap_netlink_xperm()) { + *perm = NETLINK_ROUTE_SOCKET__NLMSG; + return 0; + } + return nlmsg_perm(nlmsg_type, perm, nlmsg_route_perms, + sizeof(nlmsg_route_perms)); + break; + case SECCLASS_NETLINK_TCPDIAG_SOCKET: + if (selinux_policycap_netlink_xperm()) { + *perm = NETLINK_TCPDIAG_SOCKET__NLMSG; + return 0; + } + return nlmsg_perm(nlmsg_type, perm, nlmsg_tcpdiag_perms, + sizeof(nlmsg_tcpdiag_perms)); + break; + case SECCLASS_NETLINK_XFRM_SOCKET: + /* If the BUILD_BUG_ON() below fails you must update the + * structures at the top of this file with the new mappings + * before updating the BUILD_BUG_ON() macro! + */ + BUILD_BUG_ON(XFRM_MSG_MAX != XFRM_MSG_MIGRATE_STATE); + + if (selinux_policycap_netlink_xperm()) { + *perm = NETLINK_XFRM_SOCKET__NLMSG; + return 0; + } + return nlmsg_perm(nlmsg_type, perm, nlmsg_xfrm_perms, + sizeof(nlmsg_xfrm_perms)); + break; + case SECCLASS_NETLINK_AUDIT_SOCKET: + if (selinux_policycap_netlink_xperm()) { + *perm = NETLINK_AUDIT_SOCKET__NLMSG; + return 0; + } else if ((nlmsg_type >= AUDIT_FIRST_USER_MSG && + nlmsg_type <= AUDIT_LAST_USER_MSG) || + (nlmsg_type >= AUDIT_FIRST_USER_MSG2 && + nlmsg_type <= AUDIT_LAST_USER_MSG2)) { + *perm = NETLINK_AUDIT_SOCKET__NLMSG_RELAY; + return 0; + } + return nlmsg_perm(nlmsg_type, perm, nlmsg_audit_perms, + sizeof(nlmsg_audit_perms)); + break; + } + + /* No messaging from userspace, or class unknown/unhandled */ + return -ENOENT; +} diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c new file mode 100644 index 000000000..c7d914769 --- /dev/null +++ b/security/selinux/selinuxfs.c @@ -0,0 +1,2023 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Updated: Karl MacMillan <kmacmillan@tresys.com> + * + * Added conditional policy language extensions + * + * Updated: Hewlett-Packard <paul@paul-moore.com> + * + * Added support for the policy capability bitmap + * + * Copyright (C) 2007 Hewlett-Packard Development Company, L.P. + * Copyright (C) 2003 - 2004 Tresys Technology, LLC + * Copyright (C) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com> + */ + +#include <linux/kernel.h> +#include <linux/pagemap.h> +#include <linux/slab.h> +#include <linux/vmalloc.h> +#include <linux/fs.h> +#include <linux/fs_context.h> +#include <linux/hex.h> +#include <linux/mount.h> +#include <linux/mutex.h> +#include <linux/namei.h> +#include <linux/init.h> +#include <linux/string.h> +#include <linux/security.h> +#include <linux/major.h> +#include <linux/seq_file.h> +#include <linux/percpu.h> +#include <linux/audit.h> +#include <linux/uaccess.h> +#include <linux/kobject.h> +#include <linux/ctype.h> + +/* selinuxfs pseudo filesystem for exporting the security policy API. + Based on the proc code and the fs/nfsd/nfsctl.c code. */ + +#include "initcalls.h" +#include "flask.h" +#include "avc.h" +#include "avc_ss.h" +#include "security.h" +#include "objsec.h" +#include "conditional.h" +#include "ima.h" + +enum sel_inos { + SEL_ROOT_INO = 2, + SEL_LOAD, /* load policy */ + SEL_ENFORCE, /* get or set enforcing status */ + SEL_CONTEXT, /* validate context */ + SEL_ACCESS, /* compute access decision */ + SEL_CREATE, /* compute create labeling decision */ + SEL_RELABEL, /* compute relabeling decision */ + SEL_USER, /* compute reachable user contexts */ + SEL_POLICYVERS, /* return policy version for this kernel */ + SEL_COMMIT_BOOLS, /* commit new boolean values */ + SEL_MLS, /* return if MLS policy is enabled */ + SEL_DISABLE, /* disable SELinux until next reboot */ + SEL_MEMBER, /* compute polyinstantiation membership decision */ + SEL_CHECKREQPROT, /* check requested protection, not kernel-applied one */ + SEL_COMPAT_NET, /* whether to use old compat network packet controls */ + SEL_REJECT_UNKNOWN, /* export unknown reject handling to userspace */ + SEL_DENY_UNKNOWN, /* export unknown deny handling to userspace */ + SEL_STATUS, /* export current status using mmap() */ + SEL_POLICY, /* allow userspace to read the in kernel policy */ + SEL_VALIDATE_TRANS, /* compute validatetrans decision */ + SEL_INO_NEXT, /* The next inode number to use */ +}; + +struct selinux_fs_info { + struct dentry *bool_dir; + unsigned int bool_num; + char **bool_pending_names; + int *bool_pending_values; + struct dentry *class_dir; + unsigned long last_class_ino; + unsigned long last_ino; + struct super_block *sb; +}; + +static int selinux_fs_info_create(struct super_block *sb) +{ + struct selinux_fs_info *fsi; + + fsi = kzalloc_obj(*fsi); + if (!fsi) + return -ENOMEM; + + fsi->last_ino = SEL_INO_NEXT - 1; + fsi->sb = sb; + sb->s_fs_info = fsi; + return 0; +} + +static void selinux_fs_info_free(struct selinux_fs_info *fsi) +{ + unsigned int i; + + if (fsi) { + for (i = 0; i < fsi->bool_num; i++) + kfree(fsi->bool_pending_names[i]); + kfree(fsi->bool_pending_names); + kfree(fsi->bool_pending_values); + } + kfree(fsi); +} + +#define SEL_INITCON_INO_OFFSET 0x01000000 +#define SEL_BOOL_INO_OFFSET 0x02000000 +#define SEL_CLASS_INO_OFFSET 0x04000000 +#define SEL_POLICYCAP_INO_OFFSET 0x08000000 +#define SEL_INO_MASK 0x00ffffff + +#define BOOL_DIR_NAME "booleans" +#define CLASS_DIR_NAME "class" + +#define TMPBUFLEN 12 +static ssize_t sel_read_enforce(struct file *filp, char __user *buf, + size_t count, loff_t *ppos) +{ + char tmpbuf[TMPBUFLEN]; + ssize_t length; + + length = scnprintf(tmpbuf, TMPBUFLEN, "%d", + enforcing_enabled()); + return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); +} + +#ifdef CONFIG_SECURITY_SELINUX_DEVELOP +static ssize_t sel_write_enforce(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) + +{ + char *page = NULL; + ssize_t length; + int scan_value; + bool old_value, new_value; + + if (count >= PAGE_SIZE) + return -ENOMEM; + + /* No partial writes. */ + if (*ppos != 0) + return -EINVAL; + + page = memdup_user_nul(buf, count); + if (IS_ERR(page)) + return PTR_ERR(page); + + length = -EINVAL; + if (sscanf(page, "%d", &scan_value) != 1) + goto out; + + new_value = !!scan_value; + + old_value = enforcing_enabled(); + if (new_value != old_value) { + length = avc_has_perm(current_sid(), SECINITSID_SECURITY, + SECCLASS_SECURITY, SECURITY__SETENFORCE, + NULL); + if (length) + goto out; + audit_log(audit_context(), GFP_KERNEL, AUDIT_MAC_STATUS, + "enforcing=%d old_enforcing=%d auid=%u ses=%u" + " enabled=1 old-enabled=1 lsm=selinux res=1", + new_value, old_value, + from_kuid(&init_user_ns, audit_get_loginuid(current)), + audit_get_sessionid(current)); + enforcing_set(new_value); + if (new_value) + avc_ss_reset(0); + selnl_notify_setenforce(new_value); + selinux_status_update_setenforce(new_value); + if (!new_value) + call_blocking_lsm_notifier(LSM_POLICY_CHANGE, NULL); + + selinux_ima_measure_state(); + } + length = count; +out: + kfree(page); + return length; +} +#else +#define sel_write_enforce NULL +#endif + +static const struct file_operations sel_enforce_ops = { + .read = sel_read_enforce, + .write = sel_write_enforce, + .llseek = generic_file_llseek, +}; + +static ssize_t sel_read_handle_unknown(struct file *filp, char __user *buf, + size_t count, loff_t *ppos) +{ + char tmpbuf[TMPBUFLEN]; + ssize_t length; + ino_t ino = file_inode(filp)->i_ino; + int handle_unknown = (ino == SEL_REJECT_UNKNOWN) ? + security_get_reject_unknown() : + !security_get_allow_unknown(); + + length = scnprintf(tmpbuf, TMPBUFLEN, "%d", handle_unknown); + return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); +} + +static const struct file_operations sel_handle_unknown_ops = { + .read = sel_read_handle_unknown, + .llseek = generic_file_llseek, +}; + +static int sel_open_handle_status(struct inode *inode, struct file *filp) +{ + struct page *status = selinux_kernel_status_page(); + + if (!status) + return -ENOMEM; + + filp->private_data = status; + + return 0; +} + +static ssize_t sel_read_handle_status(struct file *filp, char __user *buf, + size_t count, loff_t *ppos) +{ + struct page *status = filp->private_data; + + BUG_ON(!status); + + return simple_read_from_buffer(buf, count, ppos, + page_address(status), + sizeof(struct selinux_kernel_status)); +} + +static int sel_mmap_handle_status(struct file *filp, + struct vm_area_struct *vma) +{ + struct page *status = filp->private_data; + unsigned long size = vma->vm_end - vma->vm_start; + + BUG_ON(!status); + + /* only allows one page from the head */ + if (vma->vm_pgoff > 0 || size != PAGE_SIZE) + return -EIO; + /* disallow writable mapping */ + if (vma->vm_flags & VM_WRITE) + return -EPERM; + /* disallow mprotect() turns it into writable */ + vm_flags_clear(vma, VM_MAYWRITE); + + return remap_pfn_range(vma, vma->vm_start, + page_to_pfn(status), + size, vma->vm_page_prot); +} + +static const struct file_operations sel_handle_status_ops = { + .open = sel_open_handle_status, + .read = sel_read_handle_status, + .mmap = sel_mmap_handle_status, + .llseek = generic_file_llseek, +}; + +static ssize_t sel_write_disable(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) + +{ + /* + * Setting disable is no longer supported, see + * https://github.com/SELinuxProject/selinux-kernel/wiki/DEPRECATE-runtime-disable + */ + pr_err_once("SELinux: %s (%d) wrote to disable. This is no longer supported.\n", + current->comm, current->pid); + return count; +} + +static const struct file_operations sel_disable_ops = { + .write = sel_write_disable, + .llseek = generic_file_llseek, +}; + +static ssize_t sel_read_policyvers(struct file *filp, char __user *buf, + size_t count, loff_t *ppos) +{ + char tmpbuf[TMPBUFLEN]; + ssize_t length; + + length = scnprintf(tmpbuf, TMPBUFLEN, "%u", POLICYDB_VERSION_MAX); + return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); +} + +static const struct file_operations sel_policyvers_ops = { + .read = sel_read_policyvers, + .llseek = generic_file_llseek, +}; + +/* declaration for sel_write_load */ +static int sel_make_bools(struct selinux_policy *newpolicy, struct dentry *bool_dir, + unsigned int *bool_num, char ***bool_pending_names, + int **bool_pending_values); +static int sel_make_classes(struct selinux_policy *newpolicy, + struct dentry *class_dir, + unsigned long *last_class_ino); + +/* declaration for sel_make_class_dirs */ +static struct dentry *sel_make_dir(struct dentry *dir, const char *name, + unsigned long *ino); + +/* declaration for sel_make_policy_nodes */ +static struct dentry *sel_make_swapover_dir(struct super_block *sb, + unsigned long *ino); + +static ssize_t sel_read_mls(struct file *filp, char __user *buf, + size_t count, loff_t *ppos) +{ + char tmpbuf[TMPBUFLEN]; + ssize_t length; + + length = scnprintf(tmpbuf, TMPBUFLEN, "%d", + security_mls_enabled()); + return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); +} + +static const struct file_operations sel_mls_ops = { + .read = sel_read_mls, + .llseek = generic_file_llseek, +}; + +struct policy_load_memory { + size_t len; + void *data; +}; + +static int sel_open_policy(struct inode *inode, struct file *filp) +{ + struct policy_load_memory *plm = NULL; + int rc; + + rc = avc_has_perm(current_sid(), SECINITSID_SECURITY, + SECCLASS_SECURITY, SECURITY__READ_POLICY, NULL); + if (rc) + return rc; + + plm = kzalloc_obj(*plm); + if (!plm) + return -ENOMEM; + + mutex_lock(&selinux_state.policy_mutex); + rc = security_read_policy(&plm->data, &plm->len); + if (rc) + goto err; + if ((size_t)i_size_read(inode) != plm->len) { + inode_lock(inode); + i_size_write(inode, plm->len); + inode_unlock(inode); + } + mutex_unlock(&selinux_state.policy_mutex); + + filp->private_data = plm; + + return 0; +err: + mutex_unlock(&selinux_state.policy_mutex); + + if (plm) + vfree(plm->data); + kfree(plm); + return rc; +} + +static int sel_release_policy(struct inode *inode, struct file *filp) +{ + struct policy_load_memory *plm = filp->private_data; + + vfree(plm->data); + kfree(plm); + + return 0; +} + +static ssize_t sel_read_policy(struct file *filp, char __user *buf, + size_t count, loff_t *ppos) +{ + struct policy_load_memory *plm = filp->private_data; + int ret; + + ret = avc_has_perm(current_sid(), SECINITSID_SECURITY, + SECCLASS_SECURITY, SECURITY__READ_POLICY, NULL); + if (ret) + return ret; + + return simple_read_from_buffer(buf, count, ppos, plm->data, plm->len); +} + +static vm_fault_t sel_mmap_policy_fault(struct vm_fault *vmf) +{ + struct policy_load_memory *plm = vmf->vma->vm_file->private_data; + unsigned long offset; + struct page *page; + + if (vmf->flags & (FAULT_FLAG_MKWRITE | FAULT_FLAG_WRITE)) + return VM_FAULT_SIGBUS; + + offset = vmf->pgoff << PAGE_SHIFT; + if (offset >= roundup(plm->len, PAGE_SIZE)) + return VM_FAULT_SIGBUS; + + page = vmalloc_to_page(plm->data + offset); + get_page(page); + + vmf->page = page; + + return 0; +} + +static const struct vm_operations_struct sel_mmap_policy_ops = { + .fault = sel_mmap_policy_fault, + .page_mkwrite = sel_mmap_policy_fault, +}; + +static int sel_mmap_policy(struct file *filp, struct vm_area_struct *vma) +{ + if (vma->vm_flags & VM_SHARED) { + /* do not allow mprotect to make mapping writable */ + vm_flags_clear(vma, VM_MAYWRITE); + + if (vma->vm_flags & VM_WRITE) + return -EACCES; + } + + vm_flags_set(vma, VM_DONTEXPAND | VM_DONTDUMP); + vma->vm_ops = &sel_mmap_policy_ops; + + return 0; +} + +static const struct file_operations sel_policy_ops = { + .open = sel_open_policy, + .read = sel_read_policy, + .mmap = sel_mmap_policy, + .release = sel_release_policy, + .llseek = generic_file_llseek, +}; + +static void sel_remove_old_bool_data(unsigned int bool_num, char **bool_names, + int *bool_values) +{ + u32 i; + + /* bool_dir cleanup */ + for (i = 0; i < bool_num; i++) + kfree(bool_names[i]); + kfree(bool_names); + kfree(bool_values); +} + +static int sel_make_policy_nodes(struct selinux_fs_info *fsi, + struct selinux_policy *newpolicy) +{ + int ret = 0; + struct dentry *tmp_parent, *tmp_bool_dir, *tmp_class_dir; + struct renamedata rd = {}; + unsigned int bool_num = 0; + char **bool_names = NULL; + int *bool_values = NULL; + unsigned long tmp_ino = fsi->last_ino; /* Don't increment last_ino in this function */ + + tmp_parent = sel_make_swapover_dir(fsi->sb, &tmp_ino); + if (IS_ERR(tmp_parent)) + return PTR_ERR(tmp_parent); + + tmp_ino = fsi->bool_dir->d_inode->i_ino - 1; /* sel_make_dir will increment and set */ + tmp_bool_dir = sel_make_dir(tmp_parent, BOOL_DIR_NAME, &tmp_ino); + if (IS_ERR(tmp_bool_dir)) { + ret = PTR_ERR(tmp_bool_dir); + goto out; + } + + tmp_ino = fsi->class_dir->d_inode->i_ino - 1; /* sel_make_dir will increment and set */ + tmp_class_dir = sel_make_dir(tmp_parent, CLASS_DIR_NAME, &tmp_ino); + if (IS_ERR(tmp_class_dir)) { + ret = PTR_ERR(tmp_class_dir); + goto out; + } + + ret = sel_make_bools(newpolicy, tmp_bool_dir, &bool_num, + &bool_names, &bool_values); + if (ret) + goto out; + + ret = sel_make_classes(newpolicy, tmp_class_dir, + &fsi->last_class_ino); + if (ret) + goto out; + + rd.old_parent = tmp_parent; + rd.new_parent = fsi->sb->s_root; + + /* booleans */ + ret = start_renaming_two_dentries(&rd, tmp_bool_dir, fsi->bool_dir); + if (ret) + goto out; + + d_exchange(tmp_bool_dir, fsi->bool_dir); + + swap(fsi->bool_num, bool_num); + swap(fsi->bool_pending_names, bool_names); + swap(fsi->bool_pending_values, bool_values); + + fsi->bool_dir = tmp_bool_dir; + end_renaming(&rd); + + /* classes */ + ret = start_renaming_two_dentries(&rd, tmp_class_dir, fsi->class_dir); + if (ret) + goto out; + + d_exchange(tmp_class_dir, fsi->class_dir); + fsi->class_dir = tmp_class_dir; + + end_renaming(&rd); + +out: + sel_remove_old_bool_data(bool_num, bool_names, bool_values); + /* Since the other temporary dirs are children of tmp_parent + * this will handle all the cleanup in the case of a failure before + * the swapover + */ + simple_recursive_removal(tmp_parent, NULL); + + return ret; +} + +static ssize_t sel_write_load(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) + +{ + struct selinux_fs_info *fsi; + struct selinux_load_state load_state; + ssize_t length; + void *data = NULL; + + /* no partial writes */ + if (*ppos) + return -EINVAL; + /* no empty policies */ + if (!count) + return -EINVAL; + + length = avc_has_perm(current_sid(), SECINITSID_SECURITY, + SECCLASS_SECURITY, SECURITY__LOAD_POLICY, NULL); + if (length) + return length; + + data = vmalloc(count); + if (!data) + return -ENOMEM; + if (copy_from_user(data, buf, count) != 0) { + length = -EFAULT; + goto out; + } + + mutex_lock(&selinux_state.policy_mutex); + length = security_load_policy(data, count, &load_state); + if (length) { + pr_warn_ratelimited("SELinux: failed to load policy\n"); + goto out_unlock; + } + fsi = file_inode(file)->i_sb->s_fs_info; + length = sel_make_policy_nodes(fsi, load_state.policy); + if (length) { + pr_warn_ratelimited("SELinux: failed to initialize selinuxfs\n"); + selinux_policy_cancel(&load_state); + goto out_unlock; + } + + selinux_policy_commit(&load_state); + length = count; + audit_log(audit_context(), GFP_KERNEL, AUDIT_MAC_POLICY_LOAD, + "auid=%u ses=%u lsm=selinux res=1", + from_kuid(&init_user_ns, audit_get_loginuid(current)), + audit_get_sessionid(current)); + +out_unlock: + mutex_unlock(&selinux_state.policy_mutex); +out: + vfree(data); + return length; +} + +static const struct file_operations sel_load_ops = { + .write = sel_write_load, + .llseek = generic_file_llseek, +}; + +static ssize_t sel_write_context(struct file *file, char *buf, size_t size) +{ + char *canon = NULL; + u32 sid, len; + ssize_t length; + + length = avc_has_perm(current_sid(), SECINITSID_SECURITY, + SECCLASS_SECURITY, SECURITY__CHECK_CONTEXT, NULL); + if (length) + goto out; + + length = security_context_to_sid(buf, size, &sid, GFP_KERNEL); + if (length) + goto out; + + length = security_sid_to_context(sid, &canon, &len); + if (length) + goto out; + + length = -ERANGE; + if (len > SIMPLE_TRANSACTION_LIMIT) { + pr_err("SELinux: %s: context size (%u) exceeds " + "payload max\n", __func__, len); + goto out; + } + + memcpy(buf, canon, len); + length = len; +out: + kfree(canon); + return length; +} + +static ssize_t sel_read_checkreqprot(struct file *filp, char __user *buf, + size_t count, loff_t *ppos) +{ + char tmpbuf[TMPBUFLEN]; + ssize_t length; + + length = scnprintf(tmpbuf, TMPBUFLEN, "%u", + checkreqprot_get()); + return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); +} + +static ssize_t sel_write_checkreqprot(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + /* + * Setting checkreqprot is no longer supported, see + * https://github.com/SELinuxProject/selinux-kernel/wiki/DEPRECATE-checkreqprot + */ + pr_err_once("SELinux: %s (%d) wrote to checkreqprot. This is no longer supported.\n", + current->comm, current->pid); + return count; +} +static const struct file_operations sel_checkreqprot_ops = { + .read = sel_read_checkreqprot, + .write = sel_write_checkreqprot, + .llseek = generic_file_llseek, +}; + +static ssize_t sel_write_validatetrans(struct file *file, + const char __user *buf, + size_t count, loff_t *ppos) +{ + char *oldcon = NULL, *newcon = NULL, *taskcon = NULL; + char *req = NULL; + u32 osid, nsid, tsid; + u16 tclass; + int rc; + + rc = avc_has_perm(current_sid(), SECINITSID_SECURITY, + SECCLASS_SECURITY, SECURITY__VALIDATE_TRANS, NULL); + if (rc) + goto out; + + rc = -ENOMEM; + if (count >= PAGE_SIZE) + goto out; + + /* No partial writes. */ + rc = -EINVAL; + if (*ppos != 0) + goto out; + + req = memdup_user_nul(buf, count); + if (IS_ERR(req)) { + rc = PTR_ERR(req); + req = NULL; + goto out; + } + + rc = -ENOMEM; + oldcon = kzalloc(count + 1, GFP_KERNEL); + if (!oldcon) + goto out; + + newcon = kzalloc(count + 1, GFP_KERNEL); + if (!newcon) + goto out; + + taskcon = kzalloc(count + 1, GFP_KERNEL); + if (!taskcon) + goto out; + + rc = -EINVAL; + if (sscanf(req, "%s %s %hu %s", oldcon, newcon, &tclass, taskcon) != 4) + goto out; + + rc = security_context_str_to_sid(oldcon, &osid, GFP_KERNEL); + if (rc) + goto out; + + rc = security_context_str_to_sid(newcon, &nsid, GFP_KERNEL); + if (rc) + goto out; + + rc = security_context_str_to_sid(taskcon, &tsid, GFP_KERNEL); + if (rc) + goto out; + + rc = security_validate_transition_user(osid, nsid, tsid, tclass); + if (!rc) + rc = count; +out: + kfree(req); + kfree(oldcon); + kfree(newcon); + kfree(taskcon); + return rc; +} + +static const struct file_operations sel_transition_ops = { + .write = sel_write_validatetrans, + .llseek = generic_file_llseek, +}; + +/* + * Remaining nodes use transaction based IO methods like nfsd/nfsctl.c + */ +static ssize_t sel_write_access(struct file *file, char *buf, size_t size); +static ssize_t sel_write_create(struct file *file, char *buf, size_t size); +static ssize_t sel_write_relabel(struct file *file, char *buf, size_t size); +static ssize_t sel_write_user(struct file *file, char *buf, size_t size); +static ssize_t sel_write_member(struct file *file, char *buf, size_t size); + +static ssize_t (*const write_op[])(struct file *, char *, size_t) = { + [SEL_ACCESS] = sel_write_access, + [SEL_CREATE] = sel_write_create, + [SEL_RELABEL] = sel_write_relabel, + [SEL_USER] = sel_write_user, + [SEL_MEMBER] = sel_write_member, + [SEL_CONTEXT] = sel_write_context, +}; + +static ssize_t selinux_transaction_write(struct file *file, const char __user *buf, size_t size, loff_t *pos) +{ + ino_t ino = file_inode(file)->i_ino; + char *data; + ssize_t rv; + + if (ino >= ARRAY_SIZE(write_op) || !write_op[ino]) + return -EINVAL; + + data = simple_transaction_get(file, buf, size); + if (IS_ERR(data)) + return PTR_ERR(data); + + rv = write_op[ino](file, data, size); + if (rv > 0) { + simple_transaction_set(file, rv); + rv = size; + } + return rv; +} + +static const struct file_operations transaction_ops = { + .write = selinux_transaction_write, + .read = simple_transaction_read, + .release = simple_transaction_release, + .llseek = generic_file_llseek, +}; + +/* + * payload - write methods + * If the method has a response, the response should be put in buf, + * and the length returned. Otherwise return 0 or -error. + */ + +static ssize_t sel_write_access(struct file *file, char *buf, size_t size) +{ + char *scon = NULL, *tcon = NULL; + u32 ssid, tsid; + u16 tclass; + struct av_decision avd; + ssize_t length; + + length = avc_has_perm(current_sid(), SECINITSID_SECURITY, + SECCLASS_SECURITY, SECURITY__COMPUTE_AV, NULL); + if (length) + goto out; + + length = -ENOMEM; + scon = kzalloc(size + 1, GFP_KERNEL); + if (!scon) + goto out; + + length = -ENOMEM; + tcon = kzalloc(size + 1, GFP_KERNEL); + if (!tcon) + goto out; + + length = -EINVAL; + if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3) + goto out; + + length = security_context_str_to_sid(scon, &ssid, GFP_KERNEL); + if (length) + goto out; + + length = security_context_str_to_sid(tcon, &tsid, GFP_KERNEL); + if (length) + goto out; + + security_compute_av_user(ssid, tsid, tclass, &avd); + + length = scnprintf(buf, SIMPLE_TRANSACTION_LIMIT, + "%x %x %x %x %u %x", + avd.allowed, 0xffffffff, + avd.auditallow, avd.auditdeny, + avd.seqno, avd.flags); +out: + kfree(tcon); + kfree(scon); + return length; +} + +static ssize_t sel_write_create(struct file *file, char *buf, size_t size) +{ + char *scon = NULL, *tcon = NULL; + char *namebuf = NULL, *objname = NULL; + u32 ssid, tsid, newsid; + u16 tclass; + ssize_t length; + char *newcon = NULL; + u32 len; + int nargs; + + length = avc_has_perm(current_sid(), SECINITSID_SECURITY, + SECCLASS_SECURITY, SECURITY__COMPUTE_CREATE, + NULL); + if (length) + goto out; + + length = -ENOMEM; + scon = kzalloc(size + 1, GFP_KERNEL); + if (!scon) + goto out; + + length = -ENOMEM; + tcon = kzalloc(size + 1, GFP_KERNEL); + if (!tcon) + goto out; + + length = -ENOMEM; + namebuf = kzalloc(size + 1, GFP_KERNEL); + if (!namebuf) + goto out; + + length = -EINVAL; + nargs = sscanf(buf, "%s %s %hu %s", scon, tcon, &tclass, namebuf); + if (nargs < 3 || nargs > 4) + goto out; + if (nargs == 4) { + /* + * If and when the name of new object to be queried contains + * either whitespace or multibyte characters, they shall be + * encoded based on the percentage-encoding rule. + * If not encoded, the sscanf logic picks up only left-half + * of the supplied name; split by a whitespace unexpectedly. + */ + char *r, *w; + int c1, c2; + + r = w = namebuf; + do { + c1 = *r++; + if (c1 == '+') + c1 = ' '; + else if (c1 == '%') { + c1 = hex_to_bin(*r++); + if (c1 < 0) + goto out; + c2 = hex_to_bin(*r++); + if (c2 < 0) + goto out; + c1 = (c1 << 4) | c2; + } + *w++ = c1; + } while (c1 != '\0'); + + objname = namebuf; + } + + length = security_context_str_to_sid(scon, &ssid, GFP_KERNEL); + if (length) + goto out; + + length = security_context_str_to_sid(tcon, &tsid, GFP_KERNEL); + if (length) + goto out; + + length = security_transition_sid_user(ssid, tsid, tclass, + objname, &newsid); + if (length) + goto out; + + length = security_sid_to_context(newsid, &newcon, &len); + if (length) + goto out; + + length = -ERANGE; + if (len > SIMPLE_TRANSACTION_LIMIT) { + pr_err("SELinux: %s: context size (%u) exceeds " + "payload max\n", __func__, len); + goto out; + } + + memcpy(buf, newcon, len); + length = len; +out: + kfree(newcon); + kfree(namebuf); + kfree(tcon); + kfree(scon); + return length; +} + +static ssize_t sel_write_relabel(struct file *file, char *buf, size_t size) +{ + char *scon = NULL, *tcon = NULL; + u32 ssid, tsid, newsid; + u16 tclass; + ssize_t length; + char *newcon = NULL; + u32 len; + + length = avc_has_perm(current_sid(), SECINITSID_SECURITY, + SECCLASS_SECURITY, SECURITY__COMPUTE_RELABEL, + NULL); + if (length) + goto out; + + length = -ENOMEM; + scon = kzalloc(size + 1, GFP_KERNEL); + if (!scon) + goto out; + + length = -ENOMEM; + tcon = kzalloc(size + 1, GFP_KERNEL); + if (!tcon) + goto out; + + length = -EINVAL; + if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3) + goto out; + + length = security_context_str_to_sid(scon, &ssid, GFP_KERNEL); + if (length) + goto out; + + length = security_context_str_to_sid(tcon, &tsid, GFP_KERNEL); + if (length) + goto out; + + length = security_change_sid(ssid, tsid, tclass, &newsid); + if (length) + goto out; + + length = security_sid_to_context(newsid, &newcon, &len); + if (length) + goto out; + + length = -ERANGE; + if (len > SIMPLE_TRANSACTION_LIMIT) + goto out; + + memcpy(buf, newcon, len); + length = len; +out: + kfree(newcon); + kfree(tcon); + kfree(scon); + return length; +} + +static ssize_t sel_write_user(struct file *file, char *buf, size_t size) +{ + pr_err_once("SELinux: %s (%d) wrote to user. This is no longer supported.\n", + current->comm, current->pid); + buf[0] = '0'; + buf[1] = 0; + return 2; +} + +static ssize_t sel_write_member(struct file *file, char *buf, size_t size) +{ + char *scon = NULL, *tcon = NULL; + u32 ssid, tsid, newsid; + u16 tclass; + ssize_t length; + char *newcon = NULL; + u32 len; + + length = avc_has_perm(current_sid(), SECINITSID_SECURITY, + SECCLASS_SECURITY, SECURITY__COMPUTE_MEMBER, + NULL); + if (length) + goto out; + + length = -ENOMEM; + scon = kzalloc(size + 1, GFP_KERNEL); + if (!scon) + goto out; + + length = -ENOMEM; + tcon = kzalloc(size + 1, GFP_KERNEL); + if (!tcon) + goto out; + + length = -EINVAL; + if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3) + goto out; + + length = security_context_str_to_sid(scon, &ssid, GFP_KERNEL); + if (length) + goto out; + + length = security_context_str_to_sid(tcon, &tsid, GFP_KERNEL); + if (length) + goto out; + + length = security_member_sid(ssid, tsid, tclass, &newsid); + if (length) + goto out; + + length = security_sid_to_context(newsid, &newcon, &len); + if (length) + goto out; + + length = -ERANGE; + if (len > SIMPLE_TRANSACTION_LIMIT) { + pr_err("SELinux: %s: context size (%u) exceeds " + "payload max\n", __func__, len); + goto out; + } + + memcpy(buf, newcon, len); + length = len; +out: + kfree(newcon); + kfree(tcon); + kfree(scon); + return length; +} + +static struct inode *sel_make_inode(struct super_block *sb, umode_t mode) +{ + struct inode *ret = new_inode(sb); + + if (ret) { + ret->i_mode = mode; + simple_inode_init_ts(ret); + } + return ret; +} + +static struct dentry *sel_attach(struct dentry *parent, const char *name, + struct inode *inode) +{ + struct dentry *dentry = d_alloc_name(parent, name); + if (unlikely(!dentry)) { + iput(inode); + return ERR_PTR(-ENOMEM); + } + d_make_persistent(dentry, inode); + dput(dentry); + return dentry; +} + +static int sel_attach_file(struct dentry *parent, const char *name, + struct inode *inode) +{ + struct dentry *dentry = sel_attach(parent, name, inode); + return PTR_ERR_OR_ZERO(dentry); +} + +static ssize_t sel_read_bool(struct file *filep, char __user *buf, + size_t count, loff_t *ppos) +{ + struct selinux_fs_info *fsi = file_inode(filep)->i_sb->s_fs_info; + char buffer[4]; + ssize_t length; + ssize_t ret; + int cur_enforcing; + unsigned index = file_inode(filep)->i_ino & SEL_INO_MASK; + const char *name = filep->f_path.dentry->d_name.name; + + mutex_lock(&selinux_state.policy_mutex); + + ret = -EINVAL; + if (index >= fsi->bool_num || strcmp(name, + fsi->bool_pending_names[index])) + goto out_unlock; + + cur_enforcing = security_get_bool_value(index); + if (cur_enforcing < 0) { + ret = cur_enforcing; + goto out_unlock; + } + length = scnprintf(buffer, sizeof(buffer), "%d %d", !!cur_enforcing, + !!fsi->bool_pending_values[index]); + mutex_unlock(&selinux_state.policy_mutex); + return simple_read_from_buffer(buf, count, ppos, buffer, length); + +out_unlock: + mutex_unlock(&selinux_state.policy_mutex); + return ret; +} + +static ssize_t sel_write_bool(struct file *filep, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct selinux_fs_info *fsi = file_inode(filep)->i_sb->s_fs_info; + char *page = NULL; + ssize_t length; + int new_value; + unsigned index = file_inode(filep)->i_ino & SEL_INO_MASK; + const char *name = filep->f_path.dentry->d_name.name; + + if (count >= PAGE_SIZE) + return -ENOMEM; + + /* No partial writes. */ + if (*ppos != 0) + return -EINVAL; + + page = memdup_user_nul(buf, count); + if (IS_ERR(page)) + return PTR_ERR(page); + + mutex_lock(&selinux_state.policy_mutex); + + length = avc_has_perm(current_sid(), SECINITSID_SECURITY, + SECCLASS_SECURITY, SECURITY__SETBOOL, + NULL); + if (length) + goto out; + + length = -EINVAL; + if (index >= fsi->bool_num || strcmp(name, + fsi->bool_pending_names[index])) + goto out; + + length = -EINVAL; + if (sscanf(page, "%d", &new_value) != 1) + goto out; + + if (new_value) + new_value = 1; + + fsi->bool_pending_values[index] = new_value; + length = count; + +out: + mutex_unlock(&selinux_state.policy_mutex); + kfree(page); + return length; +} + +static const struct file_operations sel_bool_ops = { + .read = sel_read_bool, + .write = sel_write_bool, + .llseek = generic_file_llseek, +}; + +static ssize_t sel_commit_bools_write(struct file *filep, + const char __user *buf, + size_t count, loff_t *ppos) +{ + struct selinux_fs_info *fsi = file_inode(filep)->i_sb->s_fs_info; + char *page = NULL; + ssize_t length; + int new_value; + + if (count >= PAGE_SIZE) + return -ENOMEM; + + /* No partial writes. */ + if (*ppos != 0) + return -EINVAL; + + page = memdup_user_nul(buf, count); + if (IS_ERR(page)) + return PTR_ERR(page); + + mutex_lock(&selinux_state.policy_mutex); + + length = avc_has_perm(current_sid(), SECINITSID_SECURITY, + SECCLASS_SECURITY, SECURITY__SETBOOL, + NULL); + if (length) + goto out; + + length = -EINVAL; + if (sscanf(page, "%d", &new_value) != 1) + goto out; + + length = 0; + if (new_value && fsi->bool_pending_values) + length = security_set_bools(fsi->bool_num, + fsi->bool_pending_values); + + if (!length) + length = count; + +out: + mutex_unlock(&selinux_state.policy_mutex); + kfree(page); + return length; +} + +static const struct file_operations sel_commit_bools_ops = { + .write = sel_commit_bools_write, + .llseek = generic_file_llseek, +}; + +static int sel_make_bools(struct selinux_policy *newpolicy, struct dentry *bool_dir, + unsigned int *bool_num, char ***bool_pending_names, + int **bool_pending_values) +{ + int ret; + char **names, *page; + u32 i, num; + + page = kzalloc(PAGE_SIZE, GFP_KERNEL); + if (!page) + return -ENOMEM; + + ret = security_get_bools(newpolicy, &num, &names, bool_pending_values); + if (ret) + goto out; + + *bool_num = num; + *bool_pending_names = names; + + for (i = 0; !ret && i < num; i++) { + struct inode *inode; + struct inode_security_struct *isec; + ssize_t len; + u32 sid; + + len = snprintf(page, PAGE_SIZE, "/%s/%s", BOOL_DIR_NAME, names[i]); + if (len >= PAGE_SIZE) { + ret = -ENAMETOOLONG; + break; + } + + inode = sel_make_inode(bool_dir->d_sb, S_IFREG | S_IRUGO | S_IWUSR); + if (!inode) { + ret = -ENOMEM; + break; + } + + isec = selinux_inode(inode); + ret = selinux_policy_genfs_sid(newpolicy, "selinuxfs", page, + SECCLASS_FILE, &sid); + if (ret) { + pr_warn_ratelimited("SELinux: no sid found, defaulting to security isid for %s\n", + page); + sid = SECINITSID_SECURITY; + } + + isec->sid = sid; + isec->initialized = LABEL_INITIALIZED; + inode->i_fop = &sel_bool_ops; + inode->i_ino = i|SEL_BOOL_INO_OFFSET; + + ret = sel_attach_file(bool_dir, names[i], inode); + } +out: + kfree(page); + return ret; +} + +static ssize_t sel_read_avc_cache_threshold(struct file *filp, char __user *buf, + size_t count, loff_t *ppos) +{ + char tmpbuf[TMPBUFLEN]; + ssize_t length; + + length = scnprintf(tmpbuf, TMPBUFLEN, "%u", + avc_get_cache_threshold()); + return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); +} + +static ssize_t sel_write_avc_cache_threshold(struct file *file, + const char __user *buf, + size_t count, loff_t *ppos) + +{ + char *page; + ssize_t ret; + unsigned int new_value; + + ret = avc_has_perm(current_sid(), SECINITSID_SECURITY, + SECCLASS_SECURITY, SECURITY__SETSECPARAM, + NULL); + if (ret) + return ret; + + if (count >= PAGE_SIZE) + return -ENOMEM; + + /* No partial writes. */ + if (*ppos != 0) + return -EINVAL; + + page = memdup_user_nul(buf, count); + if (IS_ERR(page)) + return PTR_ERR(page); + + ret = -EINVAL; + if (sscanf(page, "%u", &new_value) != 1) + goto out; + + avc_set_cache_threshold(new_value); + + ret = count; +out: + kfree(page); + return ret; +} + +static ssize_t sel_read_avc_hash_stats(struct file *filp, char __user *buf, + size_t count, loff_t *ppos) +{ + char *page; + ssize_t length; + + page = kmalloc(PAGE_SIZE, GFP_KERNEL); + if (!page) + return -ENOMEM; + + length = avc_get_hash_stats(page); + if (length >= 0) + length = simple_read_from_buffer(buf, count, ppos, page, length); + kfree(page); + + return length; +} + +static ssize_t sel_read_sidtab_hash_stats(struct file *filp, char __user *buf, + size_t count, loff_t *ppos) +{ + char *page; + ssize_t length; + + page = kmalloc(PAGE_SIZE, GFP_KERNEL); + if (!page) + return -ENOMEM; + + length = security_sidtab_hash_stats(page); + if (length >= 0) + length = simple_read_from_buffer(buf, count, ppos, page, + length); + kfree(page); + + return length; +} + +static const struct file_operations sel_sidtab_hash_stats_ops = { + .read = sel_read_sidtab_hash_stats, + .llseek = generic_file_llseek, +}; + +static const struct file_operations sel_avc_cache_threshold_ops = { + .read = sel_read_avc_cache_threshold, + .write = sel_write_avc_cache_threshold, + .llseek = generic_file_llseek, +}; + +static const struct file_operations sel_avc_hash_stats_ops = { + .read = sel_read_avc_hash_stats, + .llseek = generic_file_llseek, +}; + +#ifdef CONFIG_SECURITY_SELINUX_AVC_STATS +static struct avc_cache_stats *sel_avc_get_stat_idx(loff_t *idx) +{ + loff_t cpu; + + for (cpu = *idx; cpu < nr_cpu_ids; ++cpu) { + if (!cpu_possible(cpu)) + continue; + *idx = cpu + 1; + return &per_cpu(avc_cache_stats, cpu); + } + (*idx)++; + return NULL; +} + +static void *sel_avc_stats_seq_start(struct seq_file *seq, loff_t *pos) +{ + loff_t n = *pos - 1; + + if (*pos == 0) + return SEQ_START_TOKEN; + + return sel_avc_get_stat_idx(&n); +} + +static void *sel_avc_stats_seq_next(struct seq_file *seq, void *v, loff_t *pos) +{ + return sel_avc_get_stat_idx(pos); +} + +static int sel_avc_stats_seq_show(struct seq_file *seq, void *v) +{ + struct avc_cache_stats *st = v; + + if (v == SEQ_START_TOKEN) { + seq_puts(seq, + "lookups hits misses allocations reclaims frees\n"); + } else { + unsigned int lookups = st->lookups; + unsigned int misses = st->misses; + unsigned int hits = lookups - misses; + seq_printf(seq, "%u %u %u %u %u %u\n", lookups, + hits, misses, st->allocations, + st->reclaims, st->frees); + } + return 0; +} + +static void sel_avc_stats_seq_stop(struct seq_file *seq, void *v) +{ } + +static const struct seq_operations sel_avc_cache_stats_seq_ops = { + .start = sel_avc_stats_seq_start, + .next = sel_avc_stats_seq_next, + .show = sel_avc_stats_seq_show, + .stop = sel_avc_stats_seq_stop, +}; + +static int sel_open_avc_cache_stats(struct inode *inode, struct file *file) +{ + return seq_open(file, &sel_avc_cache_stats_seq_ops); +} + +static const struct file_operations sel_avc_cache_stats_ops = { + .open = sel_open_avc_cache_stats, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, +}; +#endif + +static int sel_make_avc_files(struct dentry *dir) +{ + struct super_block *sb = dir->d_sb; + struct selinux_fs_info *fsi = sb->s_fs_info; + unsigned int i; + int err = 0; + static const struct tree_descr files[] = { + { "cache_threshold", + &sel_avc_cache_threshold_ops, S_IRUGO|S_IWUSR }, + { "hash_stats", &sel_avc_hash_stats_ops, S_IRUGO }, +#ifdef CONFIG_SECURITY_SELINUX_AVC_STATS + { "cache_stats", &sel_avc_cache_stats_ops, S_IRUGO }, +#endif + }; + + for (i = 0; !err && i < ARRAY_SIZE(files); i++) { + struct inode *inode; + + inode = sel_make_inode(dir->d_sb, S_IFREG|files[i].mode); + if (!inode) + return -ENOMEM; + + inode->i_fop = files[i].ops; + inode->i_ino = ++fsi->last_ino; + + err = sel_attach_file(dir, files[i].name, inode); + } + + return err; +} + +static int sel_make_ss_files(struct dentry *dir) +{ + struct super_block *sb = dir->d_sb; + struct selinux_fs_info *fsi = sb->s_fs_info; + unsigned int i; + int err = 0; + static const struct tree_descr files[] = { + { "sidtab_hash_stats", &sel_sidtab_hash_stats_ops, S_IRUGO }, + }; + + for (i = 0; !err && i < ARRAY_SIZE(files); i++) { + struct inode *inode; + + inode = sel_make_inode(dir->d_sb, S_IFREG|files[i].mode); + if (!inode) + return -ENOMEM; + + inode->i_fop = files[i].ops; + inode->i_ino = ++fsi->last_ino; + + err = sel_attach_file(dir, files[i].name, inode); + } + + return err; +} + +static ssize_t sel_read_initcon(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + char *con; + u32 sid, len; + ssize_t ret; + + sid = file_inode(file)->i_ino&SEL_INO_MASK; + ret = security_sid_to_context(sid, &con, &len); + if (ret) + return ret; + + ret = simple_read_from_buffer(buf, count, ppos, con, len); + kfree(con); + return ret; +} + +static const struct file_operations sel_initcon_ops = { + .read = sel_read_initcon, + .llseek = generic_file_llseek, +}; + +static int sel_make_initcon_files(struct dentry *dir) +{ + unsigned int i; + int err = 0; + + for (i = 1; !err && i <= SECINITSID_NUM; i++) { + const char *s = security_get_initial_sid_context(i); + struct inode *inode; + + if (!s) + continue; + + inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO); + if (!inode) + return -ENOMEM; + + inode->i_fop = &sel_initcon_ops; + inode->i_ino = i|SEL_INITCON_INO_OFFSET; + err = sel_attach_file(dir, s, inode); + } + + return err; +} + +static inline unsigned long sel_class_to_ino(u16 class) +{ + return (class * (SEL_VEC_MAX + 1)) | SEL_CLASS_INO_OFFSET; +} + +static inline u16 sel_ino_to_class(unsigned long ino) +{ + return (ino & SEL_INO_MASK) / (SEL_VEC_MAX + 1); +} + +static inline unsigned long sel_perm_to_ino(u16 class, u32 perm) +{ + return (class * (SEL_VEC_MAX + 1) + perm) | SEL_CLASS_INO_OFFSET; +} + +static inline u32 sel_ino_to_perm(unsigned long ino) +{ + return (ino & SEL_INO_MASK) % (SEL_VEC_MAX + 1); +} + +static ssize_t sel_read_class(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + unsigned long ino = file_inode(file)->i_ino; + char res[TMPBUFLEN]; + ssize_t len = scnprintf(res, sizeof(res), "%d", sel_ino_to_class(ino)); + return simple_read_from_buffer(buf, count, ppos, res, len); +} + +static const struct file_operations sel_class_ops = { + .read = sel_read_class, + .llseek = generic_file_llseek, +}; + +static ssize_t sel_read_perm(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + unsigned long ino = file_inode(file)->i_ino; + char res[TMPBUFLEN]; + ssize_t len = scnprintf(res, sizeof(res), "%d", sel_ino_to_perm(ino)); + return simple_read_from_buffer(buf, count, ppos, res, len); +} + +static const struct file_operations sel_perm_ops = { + .read = sel_read_perm, + .llseek = generic_file_llseek, +}; + +static ssize_t sel_read_policycap(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + int value; + char tmpbuf[TMPBUFLEN]; + ssize_t length; + unsigned long i_ino = file_inode(file)->i_ino; + + value = security_policycap_supported(i_ino & SEL_INO_MASK); + length = scnprintf(tmpbuf, TMPBUFLEN, "%d", value); + + return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); +} + +static const struct file_operations sel_policycap_ops = { + .read = sel_read_policycap, + .llseek = generic_file_llseek, +}; + +static int sel_make_perm_files(struct selinux_policy *newpolicy, + char *objclass, int classvalue, + struct dentry *dir) +{ + u32 i, nperms; + int rc; + char **perms; + + rc = security_get_permissions(newpolicy, objclass, &perms, &nperms); + if (rc) + return rc; + + for (i = 0; !rc && i < nperms; i++) { + struct inode *inode; + + inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO); + if (!inode) { + rc = -ENOMEM; + break; + } + + inode->i_fop = &sel_perm_ops; + /* i+1 since perm values are 1-indexed */ + inode->i_ino = sel_perm_to_ino(classvalue, i + 1); + + rc = sel_attach_file(dir, perms[i], inode); + } + for (i = 0; i < nperms; i++) + kfree(perms[i]); + kfree(perms); + return rc; +} + +static int sel_make_class_dir_entries(struct selinux_policy *newpolicy, + char *classname, int index, + struct dentry *dir) +{ + struct super_block *sb = dir->d_sb; + struct selinux_fs_info *fsi = sb->s_fs_info; + struct dentry *dentry = NULL; + struct inode *inode = NULL; + int err; + + inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO); + if (!inode) + return -ENOMEM; + + inode->i_fop = &sel_class_ops; + inode->i_ino = sel_class_to_ino(index); + + err = sel_attach_file(dir, "index", inode); + if (err) + return err; + + dentry = sel_make_dir(dir, "perms", &fsi->last_class_ino); + if (IS_ERR(dentry)) + return PTR_ERR(dentry); + + return sel_make_perm_files(newpolicy, classname, index, dentry); +} + +static int sel_make_classes(struct selinux_policy *newpolicy, + struct dentry *class_dir, + unsigned long *last_class_ino) +{ + u32 i, nclasses; + int rc; + char **classes; + + rc = security_get_classes(newpolicy, &classes, &nclasses); + if (rc) + return rc; + + /* +2 since classes are 1-indexed */ + *last_class_ino = sel_class_to_ino(nclasses + 2); + + for (i = 0; i < nclasses; i++) { + struct dentry *class_name_dir; + + class_name_dir = sel_make_dir(class_dir, classes[i], + last_class_ino); + if (IS_ERR(class_name_dir)) { + rc = PTR_ERR(class_name_dir); + goto out; + } + + /* i+1 since class values are 1-indexed */ + rc = sel_make_class_dir_entries(newpolicy, classes[i], i + 1, + class_name_dir); + if (rc) + goto out; + } + rc = 0; +out: + for (i = 0; i < nclasses; i++) + kfree(classes[i]); + kfree(classes); + return rc; +} + +static int sel_make_policycap(struct dentry *dir) +{ + struct super_block *sb = dir->d_sb; + unsigned int iter; + struct inode *inode = NULL; + int err = 0; + + for (iter = 0; !err && iter <= POLICYDB_CAP_MAX; iter++) { + const char *name; + + if (iter < ARRAY_SIZE(selinux_policycap_names)) + name = selinux_policycap_names[iter]; + else + name = "unknown"; + + inode = sel_make_inode(sb, S_IFREG | 0444); + if (!inode) + return -ENOMEM; + + inode->i_fop = &sel_policycap_ops; + inode->i_ino = iter | SEL_POLICYCAP_INO_OFFSET; + err = sel_attach_file(dir, name, inode); + } + + return err; +} + +static struct dentry *sel_make_dir(struct dentry *dir, const char *name, + unsigned long *ino) +{ + struct inode *inode; + + inode = sel_make_inode(dir->d_sb, S_IFDIR | S_IRUGO | S_IXUGO); + if (!inode) + return ERR_PTR(-ENOMEM); + + inode->i_op = &simple_dir_inode_operations; + inode->i_fop = &simple_dir_operations; + inode->i_ino = ++(*ino); + /* directory inodes start off with i_nlink == 2 (for "." entry) */ + inc_nlink(inode); + /* bump link count on parent directory, too */ + inc_nlink(d_inode(dir)); + + return sel_attach(dir, name, inode); +} + +static int reject_all(struct mnt_idmap *idmap, struct inode *inode, int mask) +{ + return -EPERM; // no access for anyone, root or no root. +} + +static const struct inode_operations swapover_dir_inode_operations = { + .lookup = simple_lookup, + .permission = reject_all, +}; + +static struct dentry *sel_make_swapover_dir(struct super_block *sb, + unsigned long *ino) +{ + struct dentry *dentry; + struct inode *inode; + + inode = sel_make_inode(sb, S_IFDIR); + if (!inode) + return ERR_PTR(-ENOMEM); + + dentry = simple_start_creating(sb->s_root, ".swapover"); + if (IS_ERR(dentry)) { + iput(inode); + return dentry; + } + + inode->i_op = &swapover_dir_inode_operations; + inode->i_ino = ++(*ino); + /* directory inodes start off with i_nlink == 2 (for "." entry) */ + inc_nlink(inode); + d_make_persistent(dentry, inode); + inc_nlink(sb->s_root->d_inode); + simple_done_creating(dentry); + return dentry; // borrowed +} + +#define NULL_FILE_NAME "null" + +static int sel_fill_super(struct super_block *sb, struct fs_context *fc) +{ + struct selinux_fs_info *fsi; + int ret; + struct dentry *dentry; + struct inode *inode; + struct inode_security_struct *isec; + + static const struct tree_descr selinux_files[] = { + [SEL_LOAD] = {"load", &sel_load_ops, S_IRUSR|S_IWUSR}, + [SEL_ENFORCE] = {"enforce", &sel_enforce_ops, S_IRUGO|S_IWUSR}, + [SEL_CONTEXT] = {"context", &transaction_ops, S_IRUGO|S_IWUGO}, + [SEL_ACCESS] = {"access", &transaction_ops, S_IRUGO|S_IWUGO}, + [SEL_CREATE] = {"create", &transaction_ops, S_IRUGO|S_IWUGO}, + [SEL_RELABEL] = {"relabel", &transaction_ops, S_IRUGO|S_IWUGO}, + [SEL_USER] = {"user", &transaction_ops, S_IRUGO|S_IWUGO}, + [SEL_POLICYVERS] = {"policyvers", &sel_policyvers_ops, S_IRUGO}, + [SEL_COMMIT_BOOLS] = {"commit_pending_bools", &sel_commit_bools_ops, S_IWUSR}, + [SEL_MLS] = {"mls", &sel_mls_ops, S_IRUGO}, + [SEL_DISABLE] = {"disable", &sel_disable_ops, S_IWUSR}, + [SEL_MEMBER] = {"member", &transaction_ops, S_IRUGO|S_IWUGO}, + [SEL_CHECKREQPROT] = {"checkreqprot", &sel_checkreqprot_ops, S_IRUGO|S_IWUSR}, + [SEL_REJECT_UNKNOWN] = {"reject_unknown", &sel_handle_unknown_ops, S_IRUGO}, + [SEL_DENY_UNKNOWN] = {"deny_unknown", &sel_handle_unknown_ops, S_IRUGO}, + [SEL_STATUS] = {"status", &sel_handle_status_ops, S_IRUGO}, + [SEL_POLICY] = {"policy", &sel_policy_ops, S_IRUGO}, + [SEL_VALIDATE_TRANS] = {"validatetrans", &sel_transition_ops, + S_IWUGO}, + /* last one */ {"", NULL, 0} + }; + + ret = selinux_fs_info_create(sb); + if (ret) + goto err; + + ret = simple_fill_super(sb, SELINUX_MAGIC, selinux_files); + if (ret) + goto err; + + fsi = sb->s_fs_info; + fsi->bool_dir = sel_make_dir(sb->s_root, BOOL_DIR_NAME, &fsi->last_ino); + if (IS_ERR(fsi->bool_dir)) { + ret = PTR_ERR(fsi->bool_dir); + fsi->bool_dir = NULL; + goto err; + } + + ret = -ENOMEM; + inode = sel_make_inode(sb, S_IFCHR | S_IRUGO | S_IWUGO); + if (!inode) + goto err; + + inode->i_ino = ++fsi->last_ino; + isec = selinux_inode(inode); + isec->sid = SECINITSID_DEVNULL; + isec->sclass = SECCLASS_CHR_FILE; + isec->initialized = LABEL_INITIALIZED; + + init_special_inode(inode, S_IFCHR | S_IRUGO | S_IWUGO, MKDEV(MEM_MAJOR, 3)); + ret = sel_attach_file(sb->s_root, NULL_FILE_NAME, inode); + if (ret) + goto err; + + dentry = sel_make_dir(sb->s_root, "avc", &fsi->last_ino); + if (IS_ERR(dentry)) { + ret = PTR_ERR(dentry); + goto err; + } + + ret = sel_make_avc_files(dentry); + if (ret) + goto err; + + dentry = sel_make_dir(sb->s_root, "ss", &fsi->last_ino); + if (IS_ERR(dentry)) { + ret = PTR_ERR(dentry); + goto err; + } + + ret = sel_make_ss_files(dentry); + if (ret) + goto err; + + dentry = sel_make_dir(sb->s_root, "initial_contexts", &fsi->last_ino); + if (IS_ERR(dentry)) { + ret = PTR_ERR(dentry); + goto err; + } + + ret = sel_make_initcon_files(dentry); + if (ret) + goto err; + + fsi->class_dir = sel_make_dir(sb->s_root, CLASS_DIR_NAME, &fsi->last_ino); + if (IS_ERR(fsi->class_dir)) { + ret = PTR_ERR(fsi->class_dir); + fsi->class_dir = NULL; + goto err; + } + + dentry = sel_make_dir(sb->s_root, "policy_capabilities", &fsi->last_ino); + if (IS_ERR(dentry)) { + ret = PTR_ERR(dentry); + goto err; + } + + ret = sel_make_policycap(dentry); + if (ret) { + pr_err("SELinux: failed to load policy capabilities\n"); + goto err; + } + + return 0; +err: + pr_err("SELinux: %s: failed while creating inodes\n", + __func__); + + return ret; +} + +static int sel_get_tree(struct fs_context *fc) +{ + return get_tree_single(fc, sel_fill_super); +} + +static const struct fs_context_operations sel_context_ops = { + .get_tree = sel_get_tree, +}; + +static int sel_init_fs_context(struct fs_context *fc) +{ + fc->ops = &sel_context_ops; + return 0; +} + +static void sel_kill_sb(struct super_block *sb) +{ + struct selinux_fs_info *fsi = sb->s_fs_info; + + kill_anon_super(sb); + selinux_fs_info_free(fsi); +} + +static struct file_system_type sel_fs_type = { + .name = "selinuxfs", + .init_fs_context = sel_init_fs_context, + .kill_sb = sel_kill_sb, +}; + +struct path selinux_null __ro_after_init; + +int __init init_sel_fs(void) +{ + struct qstr null_name = QSTR(NULL_FILE_NAME); + int err; + + if (!selinux_enabled_boot) + return 0; + + err = sysfs_create_mount_point(fs_kobj, "selinux"); + if (err) + return err; + + err = register_filesystem(&sel_fs_type); + if (err) + goto err_remove_mount_point; + + selinux_null.mnt = kern_mount(&sel_fs_type); + if (IS_ERR(selinux_null.mnt)) { + pr_err("selinuxfs: could not mount!\n"); + err = PTR_ERR(selinux_null.mnt); + selinux_null.mnt = NULL; + goto err_unregister_fs; + } + + selinux_null.dentry = try_lookup_noperm(&null_name, + selinux_null.mnt->mnt_root); + if (IS_ERR(selinux_null.dentry)) { + pr_err("selinuxfs: could not lookup null!\n"); + err = PTR_ERR(selinux_null.dentry); + selinux_null.dentry = NULL; + goto err_unmount; + } + + /* + * Try to pre-allocate the status page, so the sequence number of the + * initial policy load can be stored. + */ + (void) selinux_kernel_status_page(); + + return 0; + +err_unmount: + kern_unmount(selinux_null.mnt); + selinux_null.mnt = NULL; +err_unregister_fs: + unregister_filesystem(&sel_fs_type); +err_remove_mount_point: + sysfs_remove_mount_point(fs_kobj, "selinux"); + return err; +} diff --git a/security/selinux/ss/avtab.c b/security/selinux/ss/avtab.c new file mode 100644 index 000000000..0f94edd01 --- /dev/null +++ b/security/selinux/ss/avtab.c @@ -0,0 +1,618 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Implementation of the access vector table type. + * + * Author : Stephen Smalley, <stephen.smalley.work@gmail.com> + */ + +/* Updated: Frank Mayer <mayerf@tresys.com> and + * Karl MacMillan <kmacmillan@tresys.com> + * Added conditional policy language extensions + * Copyright (C) 2003 Tresys Technology, LLC + * + * Updated: Yuichi Nakamura <ynakam@hitachisoft.jp> + * Tuned number of hash slots for avtab to reduce memory usage + */ + +#include <linux/bitops.h> +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/errno.h> +#include "avtab.h" +#include "policydb.h" +#include "hash.h" + +static struct kmem_cache *avtab_node_cachep __ro_after_init; +static struct kmem_cache *avtab_xperms_cachep __ro_after_init; + +static inline u32 avtab_hash(const struct avtab_key *keyp, u32 mask) +{ + return av_hash((u32)keyp->target_class, (u32)keyp->target_type, + (u32)keyp->source_type, mask); +} + +static struct avtab_node *avtab_insert_node(struct avtab *h, + struct avtab_node **dst, + const struct avtab_key *key, + const struct avtab_datum *datum) +{ + struct avtab_node *newnode; + struct avtab_extended_perms *xperms; + newnode = kmem_cache_zalloc(avtab_node_cachep, GFP_KERNEL); + if (newnode == NULL) + return NULL; + newnode->key = *key; + + if (key->specified & AVTAB_XPERMS) { + xperms = kmem_cache_zalloc(avtab_xperms_cachep, GFP_KERNEL); + if (xperms == NULL) { + kmem_cache_free(avtab_node_cachep, newnode); + return NULL; + } + *xperms = *(datum->u.xperms); + newnode->datum.u.xperms = xperms; + } else { + newnode->datum.u.data = datum->u.data; + } + + newnode->next = *dst; + *dst = newnode; + + h->nel++; + return newnode; +} + +static int avtab_node_cmp(const struct avtab_key *key1, + const struct avtab_key *key2) +{ + u16 specified = key1->specified & ~(AVTAB_ENABLED | AVTAB_ENABLED_OLD); + + if (key1->source_type == key2->source_type && + key1->target_type == key2->target_type && + key1->target_class == key2->target_class && + (specified & key2->specified)) + return 0; + if (key1->source_type < key2->source_type) + return -1; + if (key1->source_type == key2->source_type && + key1->target_type < key2->target_type) + return -1; + if (key1->source_type == key2->source_type && + key1->target_type == key2->target_type && + key1->target_class < key2->target_class) + return -1; + return 1; +} + +static int avtab_insert(struct avtab *h, const struct avtab_key *key, + const struct avtab_datum *datum) +{ + u32 hvalue; + struct avtab_node *prev, *cur, *newnode; + int cmp; + + if (!h || !h->nslot || h->nel == U32_MAX) + return -EINVAL; + + hvalue = avtab_hash(key, h->mask); + for (prev = NULL, cur = h->htable[hvalue]; cur; + prev = cur, cur = cur->next) { + cmp = avtab_node_cmp(key, &cur->key); + /* extended perms may not be unique */ + if (cmp == 0 && !(key->specified & AVTAB_XPERMS)) + return -EEXIST; + if (cmp <= 0) + break; + } + + newnode = avtab_insert_node(h, prev ? &prev->next : &h->htable[hvalue], + key, datum); + if (!newnode) + return -ENOMEM; + + return 0; +} + +/* Unlike avtab_insert(), this function allow multiple insertions of the same + * key/specified mask into the table, as needed by the conditional avtab. + * It also returns a pointer to the node inserted. + */ +struct avtab_node *avtab_insert_nonunique(struct avtab *h, + const struct avtab_key *key, + const struct avtab_datum *datum) +{ + u32 hvalue; + struct avtab_node *prev, *cur; + int cmp; + + if (!h || !h->nslot || h->nel == U32_MAX) + return NULL; + hvalue = avtab_hash(key, h->mask); + for (prev = NULL, cur = h->htable[hvalue]; cur; + prev = cur, cur = cur->next) { + cmp = avtab_node_cmp(key, &cur->key); + if (cmp <= 0) + break; + } + return avtab_insert_node(h, prev ? &prev->next : &h->htable[hvalue], + key, datum); +} + +/* This search function returns a node pointer, and can be used in + * conjunction with avtab_search_next_node() + */ +struct avtab_node *avtab_search_node(struct avtab *h, + const struct avtab_key *key) +{ + u32 hvalue; + struct avtab_node *cur; + int cmp; + + if (!h || !h->nslot) + return NULL; + + hvalue = avtab_hash(key, h->mask); + for (cur = h->htable[hvalue]; cur; cur = cur->next) { + cmp = avtab_node_cmp(key, &cur->key); + if (cmp == 0) + return cur; + if (cmp < 0) + break; + } + return NULL; +} + +struct avtab_node *avtab_search_node_next(struct avtab_node *node, + u16 specified) +{ + struct avtab_key tmp_key; + struct avtab_node *cur; + int cmp; + + if (!node) + return NULL; + tmp_key = node->key; + tmp_key.specified = specified; + for (cur = node->next; cur; cur = cur->next) { + cmp = avtab_node_cmp(&tmp_key, &cur->key); + if (cmp == 0) + return cur; + if (cmp < 0) + break; + } + return NULL; +} + +void avtab_destroy(struct avtab *h) +{ + u32 i; + struct avtab_node *cur, *temp; + + if (!h) + return; + + for (i = 0; i < h->nslot; i++) { + cur = h->htable[i]; + while (cur) { + temp = cur; + cur = cur->next; + if (temp->key.specified & AVTAB_XPERMS) + kmem_cache_free(avtab_xperms_cachep, + temp->datum.u.xperms); + kmem_cache_free(avtab_node_cachep, temp); + } + } + kvfree(h->htable); + h->htable = NULL; + h->nel = 0; + h->nslot = 0; + h->mask = 0; +} + +void avtab_init(struct avtab *h) +{ + h->htable = NULL; + h->nel = 0; + h->nslot = 0; + h->mask = 0; +} + +static int avtab_alloc_common(struct avtab *h, u32 nslot) +{ + if (!nslot) + return 0; + + h->htable = kvcalloc(nslot, sizeof(void *), GFP_KERNEL); + if (!h->htable) + return -ENOMEM; + + h->nslot = nslot; + h->mask = nslot - 1; + return 0; +} + +int avtab_alloc(struct avtab *h, u32 nrules) +{ + int rc; + u32 nslot = 0; + + if (nrules != 0) { + nslot = nrules > 3 ? rounddown_pow_of_two(nrules / 2) : 2; + if (nslot > MAX_AVTAB_HASH_BUCKETS) + nslot = MAX_AVTAB_HASH_BUCKETS; + + rc = avtab_alloc_common(h, nslot); + if (rc) + return rc; + } + + pr_debug("SELinux: %d avtab hash slots, %d rules.\n", nslot, nrules); + return 0; +} + +int avtab_alloc_dup(struct avtab *new, const struct avtab *orig) +{ + return avtab_alloc_common(new, orig->nslot); +} + +#ifdef CONFIG_SECURITY_SELINUX_DEBUG +void avtab_hash_eval(struct avtab *h, const char *tag) +{ + u32 i, chain_len, slots_used, max_chain_len; + unsigned long long chain2_len_sum; + struct avtab_node *cur; + + slots_used = 0; + max_chain_len = 0; + chain2_len_sum = 0; + for (i = 0; i < h->nslot; i++) { + cur = h->htable[i]; + if (cur) { + slots_used++; + chain_len = 0; + while (cur) { + chain_len++; + cur = cur->next; + } + + if (chain_len > max_chain_len) + max_chain_len = chain_len; + chain2_len_sum += + (unsigned long long)chain_len * chain_len; + } + } + + pr_debug("SELinux: %s: %d entries and %d/%d buckets used, " + "longest chain length %d, sum of chain length^2 %llu\n", + tag, h->nel, slots_used, h->nslot, max_chain_len, + chain2_len_sum); +} +#endif /* CONFIG_SECURITY_SELINUX_DEBUG */ + +/* clang-format off */ +static const uint16_t spec_order[] = { + AVTAB_ALLOWED, + AVTAB_AUDITDENY, + AVTAB_AUDITALLOW, + AVTAB_TRANSITION, + AVTAB_CHANGE, + AVTAB_MEMBER, + AVTAB_XPERMS_ALLOWED, + AVTAB_XPERMS_AUDITALLOW, + AVTAB_XPERMS_DONTAUDIT +}; +/* clang-format on */ + +int avtab_read_item(struct avtab *a, struct policy_file *fp, struct policydb *pol, + int (*insertf)(struct avtab *a, const struct avtab_key *k, + const struct avtab_datum *d, void *p), + void *p, bool conditional) +{ + __le16 buf16[4]; + u16 enabled; + u32 items, items2, val, i; + struct avtab_key key; + struct avtab_datum datum; + struct avtab_extended_perms xperms; + __le32 buf32[ARRAY_SIZE(xperms.perms.p)]; + int rc; + unsigned int vers = pol->policyvers; + + memset(&key, 0, sizeof(struct avtab_key)); + memset(&datum, 0, sizeof(struct avtab_datum)); + + if (vers < POLICYDB_VERSION_AVTAB) { + rc = next_entry(buf32, fp, sizeof(u32)); + if (rc) { + pr_err("SELinux: avtab: truncated entry\n"); + return rc; + } + /* Read five or more items: source type, target type, + * target class, AV type, and at least one datum. + */ + items2 = le32_to_cpu(buf32[0]); + if (items2 < 5 || items2 > ARRAY_SIZE(buf32)) { + pr_err("SELinux: avtab: invalid item count\n"); + return -EINVAL; + } + rc = next_entry(buf32, fp, sizeof(u32) * items2); + if (rc) { + pr_err("SELinux: avtab: truncated entry\n"); + return rc; + } + items = 0; + + val = le32_to_cpu(buf32[items++]); + key.source_type = (u16)val; + if (key.source_type != val) { + pr_err("SELinux: avtab: truncated source type\n"); + return -EINVAL; + } + val = le32_to_cpu(buf32[items++]); + key.target_type = (u16)val; + if (key.target_type != val) { + pr_err("SELinux: avtab: truncated target type\n"); + return -EINVAL; + } + val = le32_to_cpu(buf32[items++]); + key.target_class = (u16)val; + if (key.target_class != val) { + pr_err("SELinux: avtab: truncated target class\n"); + return -EINVAL; + } + + if (!policydb_type_isvalid(pol, key.source_type) || + !policydb_type_isvalid(pol, key.target_type) || + !policydb_class_isvalid(pol, key.target_class)) { + pr_err("SELinux: avtab: invalid type or class\n"); + return -EINVAL; + } + + val = le32_to_cpu(buf32[items++]); + enabled = (val & AVTAB_ENABLED_OLD) ? AVTAB_ENABLED : 0; + + if (!(val & (AVTAB_AV | AVTAB_TYPE))) { + pr_err("SELinux: avtab: null entry\n"); + return -EINVAL; + } + if ((val & AVTAB_AV) && (val & AVTAB_TYPE)) { + pr_err("SELinux: avtab: entry has both access vectors and types\n"); + return -EINVAL; + } + if (val & AVTAB_XPERMS) { + pr_err("SELinux: avtab: entry has extended permissions\n"); + return -EINVAL; + } + + for (i = 0; i < ARRAY_SIZE(spec_order); i++) { + if (val & spec_order[i]) { + if (items >= items2) { + pr_err("SELinux: avtab: entry has too many items (%d/%d)\n", + items + 1, items2); + return -EINVAL; + } + key.specified = spec_order[i] | enabled; + datum.u.data = le32_to_cpu(buf32[items++]); + + if ((key.specified & AVTAB_TYPE) && + !policydb_simpletype_isvalid(pol, datum.u.data)) { + pr_err("SELinux: avtab: invalid type\n"); + return -EINVAL; + } + + rc = insertf(a, &key, &datum, p); + if (rc) + return rc; + } + } + + if (items != items2) { + pr_err("SELinux: avtab: entry only had %d items, expected %d\n", + items2, items); + return -EINVAL; + } + return 0; + } + + rc = next_entry(buf16, fp, sizeof(u16) * 4); + if (rc) { + pr_err("SELinux: avtab: truncated entry\n"); + return rc; + } + + items = 0; + key.source_type = le16_to_cpu(buf16[items++]); + key.target_type = le16_to_cpu(buf16[items++]); + key.target_class = le16_to_cpu(buf16[items++]); + key.specified = le16_to_cpu(buf16[items++]); + + if (!policydb_type_isvalid(pol, key.source_type) || + !policydb_type_isvalid(pol, key.target_type) || + !policydb_class_isvalid(pol, key.target_class)) { + pr_err("SELinux: avtab: invalid type or class\n"); + return -EINVAL; + } + + if (hweight16(key.specified & ~AVTAB_ENABLED) != 1) { + pr_err("SELinux: avtab: not exactly one specifier\n"); + return -EINVAL; + } + + if (key.specified & ~AVTAB_SPECIFIER_MASK) { + pr_err("SELinux: avtab: invalid specifier\n"); + return -EINVAL; + } + + if ((vers < POLICYDB_VERSION_XPERMS_IOCTL) && + (key.specified & AVTAB_XPERMS)) { + pr_err("SELinux: avtab: policy version %u does not " + "support extended permissions rules and one " + "was specified\n", + vers); + return -EINVAL; + } else if ((vers < POLICYDB_VERSION_COND_XPERMS) && + (key.specified & AVTAB_XPERMS) && conditional) { + pr_err("SELinux: avtab: policy version %u does not " + "support extended permissions rules in conditional " + "policies and one was specified\n", + vers); + return -EINVAL; + } else if (key.specified & AVTAB_XPERMS) { + memset(&xperms, 0, sizeof(struct avtab_extended_perms)); + rc = next_entry(&xperms.specified, fp, sizeof(u8)); + if (rc) { + pr_err("SELinux: avtab: truncated entry\n"); + return rc; + } + if (!avtab_is_valid_xperm_specified(xperms.specified)) + pr_warn_once_policyload(pol, + "SELinux: avtab: unsupported xperm specifier %#x\n", + xperms.specified); + rc = next_entry(&xperms.driver, fp, sizeof(u8)); + if (rc) { + pr_err("SELinux: avtab: truncated entry\n"); + return rc; + } + rc = next_entry(buf32, fp, + sizeof(u32) * ARRAY_SIZE(xperms.perms.p)); + if (rc) { + pr_err("SELinux: avtab: truncated entry\n"); + return rc; + } + for (i = 0; i < ARRAY_SIZE(xperms.perms.p); i++) + xperms.perms.p[i] = le32_to_cpu(buf32[i]); + datum.u.xperms = &xperms; + } else { + rc = next_entry(buf32, fp, sizeof(u32)); + if (rc) { + pr_err("SELinux: avtab: truncated entry\n"); + return rc; + } + datum.u.data = le32_to_cpu(*buf32); + } + if ((key.specified & AVTAB_TYPE) && + !policydb_simpletype_isvalid(pol, datum.u.data)) { + pr_err("SELinux: avtab: invalid type\n"); + return -EINVAL; + } + return insertf(a, &key, &datum, p); +} + +static int avtab_insertf(struct avtab *a, const struct avtab_key *k, + const struct avtab_datum *d, void *p) +{ + return avtab_insert(a, k, d); +} + +int avtab_read(struct avtab *a, struct policy_file *fp, struct policydb *pol) +{ + int rc; + __le32 buf[1]; + u32 nel, i; + + rc = next_entry(buf, fp, sizeof(u32)); + if (rc < 0) { + pr_err("SELinux: avtab: truncated table\n"); + goto bad; + } + nel = le32_to_cpu(buf[0]); + if (!nel) { + pr_err("SELinux: avtab: table is empty\n"); + rc = -EINVAL; + goto bad; + } + + /* avtab_read_item() reads at least 96 bytes for any valid entry */ + rc = size_check(3 * sizeof(u32), nel, fp); + if (rc) + goto bad; + + rc = avtab_alloc(a, nel); + if (rc) + goto bad; + + for (i = 0; i < nel; i++) { + rc = avtab_read_item(a, fp, pol, avtab_insertf, NULL, false); + if (rc) { + if (rc == -ENOMEM) + pr_err("SELinux: avtab: out of memory\n"); + else if (rc == -EEXIST) + pr_err("SELinux: avtab: duplicate entry\n"); + + goto bad; + } + } + + rc = 0; +out: + return rc; + +bad: + avtab_destroy(a); + goto out; +} + +int avtab_write_item(struct policydb *p, const struct avtab_node *cur, struct policy_file *fp) +{ + __le16 buf16[4]; + __le32 buf32[ARRAY_SIZE(cur->datum.u.xperms->perms.p)]; + int rc; + unsigned int i; + + buf16[0] = cpu_to_le16(cur->key.source_type); + buf16[1] = cpu_to_le16(cur->key.target_type); + buf16[2] = cpu_to_le16(cur->key.target_class); + buf16[3] = cpu_to_le16(cur->key.specified); + rc = put_entry(buf16, sizeof(u16), 4, fp); + if (rc) + return rc; + + if (cur->key.specified & AVTAB_XPERMS) { + rc = put_entry(&cur->datum.u.xperms->specified, sizeof(u8), 1, + fp); + if (rc) + return rc; + rc = put_entry(&cur->datum.u.xperms->driver, sizeof(u8), 1, fp); + if (rc) + return rc; + for (i = 0; i < ARRAY_SIZE(cur->datum.u.xperms->perms.p); i++) + buf32[i] = cpu_to_le32(cur->datum.u.xperms->perms.p[i]); + rc = put_entry(buf32, sizeof(u32), + ARRAY_SIZE(cur->datum.u.xperms->perms.p), fp); + } else { + buf32[0] = cpu_to_le32(cur->datum.u.data); + rc = put_entry(buf32, sizeof(u32), 1, fp); + } + if (rc) + return rc; + return 0; +} + +int avtab_write(struct policydb *p, struct avtab *a, struct policy_file *fp) +{ + u32 i; + int rc = 0; + struct avtab_node *cur; + __le32 buf[1]; + + buf[0] = cpu_to_le32(a->nel); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + + for (i = 0; i < a->nslot; i++) { + for (cur = a->htable[i]; cur; cur = cur->next) { + rc = avtab_write_item(p, cur, fp); + if (rc) + return rc; + } + } + + return rc; +} + +void __init avtab_cache_init(void) +{ + avtab_node_cachep = KMEM_CACHE(avtab_node, SLAB_PANIC); + avtab_xperms_cachep = KMEM_CACHE(avtab_extended_perms, SLAB_PANIC); +} diff --git a/security/selinux/ss/avtab.h b/security/selinux/ss/avtab.h new file mode 100644 index 000000000..1de4cce28 --- /dev/null +++ b/security/selinux/ss/avtab.h @@ -0,0 +1,141 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * An access vector table (avtab) is a hash table + * of access vectors and transition types indexed + * by a type pair and a class. An access vector + * table is used to represent the type enforcement + * tables. + * + * Author : Stephen Smalley, <stephen.smalley.work@gmail.com> + */ + +/* Updated: Frank Mayer <mayerf@tresys.com> and + * Karl MacMillan <kmacmillan@tresys.com> + * Added conditional policy language extensions + * Copyright (C) 2003 Tresys Technology, LLC + * + * Updated: Yuichi Nakamura <ynakam@hitachisoft.jp> + * Tuned number of hash slots for avtab to reduce memory usage + */ + +#ifndef _SS_AVTAB_H_ +#define _SS_AVTAB_H_ + +#include "security.h" + +struct avtab_key { + u16 source_type; /* source type */ + u16 target_type; /* target type */ + u16 target_class; /* target object class */ +#define AVTAB_ALLOWED 0x0001 +#define AVTAB_AUDITALLOW 0x0002 +#define AVTAB_AUDITDENY 0x0004 +#define AVTAB_AV (AVTAB_ALLOWED | AVTAB_AUDITALLOW | AVTAB_AUDITDENY) +#define AVTAB_TRANSITION 0x0010 +#define AVTAB_MEMBER 0x0020 +#define AVTAB_CHANGE 0x0040 +#define AVTAB_TYPE (AVTAB_TRANSITION | AVTAB_MEMBER | AVTAB_CHANGE) +/* extended permissions */ +#define AVTAB_XPERMS_ALLOWED 0x0100 +#define AVTAB_XPERMS_AUDITALLOW 0x0200 +#define AVTAB_XPERMS_DONTAUDIT 0x0400 +#define AVTAB_XPERMS \ + (AVTAB_XPERMS_ALLOWED | AVTAB_XPERMS_AUDITALLOW | \ + AVTAB_XPERMS_DONTAUDIT) +#define AVTAB_ENABLED_OLD 0x80000000 /* reserved for used in cond_avtab */ +#define AVTAB_ENABLED 0x8000 /* reserved for used in cond_avtab */ +#define AVTAB_SPECIFIER_MASK (AVTAB_AV | AVTAB_TYPE | AVTAB_XPERMS | AVTAB_ENABLED) + u16 specified; /* what field is specified */ +}; + +/* + * For operations that require more than the 32 permissions provided by the avc + * extended permissions may be used to provide 256 bits of permissions. + */ +struct avtab_extended_perms { +/* These are not flags. All 256 values may be used */ +#define AVTAB_XPERMS_IOCTLFUNCTION 0x01 +#define AVTAB_XPERMS_IOCTLDRIVER 0x02 +#define AVTAB_XPERMS_NLMSG 0x03 + /* extension of the avtab_key specified */ + u8 specified; /* ioctl, netfilter, ... */ + /* + * if 256 bits is not adequate as is often the case with ioctls, then + * multiple extended perms may be used and the driver field + * specifies which permissions are included. + */ + u8 driver; + /* 256 bits of permissions */ + struct extended_perms_data perms; +}; + +static inline bool avtab_is_valid_xperm_specified(u8 specified) +{ + switch (specified) { + case AVTAB_XPERMS_IOCTLFUNCTION: + case AVTAB_XPERMS_IOCTLDRIVER: + case AVTAB_XPERMS_NLMSG: + return true; + default: + return false; + } +} + +struct avtab_datum { + union { + u32 data; /* access vector or type value */ + struct avtab_extended_perms *xperms; + } u; +}; + +struct avtab_node { + struct avtab_key key; + struct avtab_datum datum; + struct avtab_node *next; +}; + +struct avtab { + struct avtab_node **htable; + u32 nel; /* number of elements */ + u32 nslot; /* number of hash slots */ + u32 mask; /* mask to compute hash func */ +}; + +void avtab_init(struct avtab *h); +int avtab_alloc(struct avtab *h, u32 nrules); +int avtab_alloc_dup(struct avtab *new, const struct avtab *orig); +void avtab_destroy(struct avtab *h); + +#define MAX_AVTAB_HASH_BITS 16 +#define MAX_AVTAB_HASH_BUCKETS (1 << MAX_AVTAB_HASH_BITS) + +#ifdef CONFIG_SECURITY_SELINUX_DEBUG +void avtab_hash_eval(struct avtab *h, const char *tag); +#else +static inline void avtab_hash_eval(struct avtab *h, const char *tag) +{ +} +#endif + +struct policydb; +struct policy_file; +int avtab_read_item(struct avtab *a, struct policy_file *fp, struct policydb *pol, + int (*insert)(struct avtab *a, const struct avtab_key *k, + const struct avtab_datum *d, void *p), + void *p, bool conditional); + +int avtab_read(struct avtab *a, struct policy_file *fp, struct policydb *pol); +int avtab_write_item(struct policydb *p, const struct avtab_node *cur, + struct policy_file *fp); +int avtab_write(struct policydb *p, struct avtab *a, struct policy_file *fp); + +struct avtab_node *avtab_insert_nonunique(struct avtab *h, + const struct avtab_key *key, + const struct avtab_datum *datum); + +struct avtab_node *avtab_search_node(struct avtab *h, + const struct avtab_key *key); +struct avtab_node *avtab_search_node_next(struct avtab_node *node, + u16 specified); + +#endif /* _SS_AVTAB_H_ */ diff --git a/security/selinux/ss/conditional.c b/security/selinux/ss/conditional.c new file mode 100644 index 000000000..2956dd7ed --- /dev/null +++ b/security/selinux/ss/conditional.c @@ -0,0 +1,765 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* Authors: Karl MacMillan <kmacmillan@tresys.com> + * Frank Mayer <mayerf@tresys.com> + * Copyright (C) 2003 - 2004 Tresys Technology, LLC + */ + +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/string.h> +#include <linux/spinlock.h> +#include <linux/slab.h> + +#include "security.h" +#include "conditional.h" +#include "policydb.h" +#include "services.h" + +/* + * cond_evaluate_expr evaluates a conditional expr + * in reverse polish notation. It returns true (1), false (0), + * or undefined (-1). Undefined occurs when the expression + * exceeds the stack depth of COND_EXPR_MAXDEPTH. + */ +static int cond_evaluate_expr(struct policydb *p, struct cond_expr *expr) +{ + u32 i; + int s[COND_EXPR_MAXDEPTH]; + int sp = -1; + + if (expr->len == 0) + return -1; + + for (i = 0; i < expr->len; i++) { + struct cond_expr_node *node = &expr->nodes[i]; + + switch (node->expr_type) { + case COND_BOOL: + if (sp == (COND_EXPR_MAXDEPTH - 1)) + return -1; + sp++; + s[sp] = p->bool_val_to_struct[node->boolean - 1]->state; + break; + case COND_NOT: + if (sp < 0) + return -1; + s[sp] = !s[sp]; + break; + case COND_OR: + if (sp < 1) + return -1; + sp--; + s[sp] |= s[sp + 1]; + break; + case COND_AND: + if (sp < 1) + return -1; + sp--; + s[sp] &= s[sp + 1]; + break; + case COND_XOR: + if (sp < 1) + return -1; + sp--; + s[sp] ^= s[sp + 1]; + break; + case COND_EQ: + if (sp < 1) + return -1; + sp--; + s[sp] = (s[sp] == s[sp + 1]); + break; + case COND_NEQ: + if (sp < 1) + return -1; + sp--; + s[sp] = (s[sp] != s[sp + 1]); + break; + default: + return -1; + } + } + return s[0]; +} + +/* + * evaluate_cond_node evaluates the conditional stored in + * a struct cond_node and if the result is different than the + * current state of the node it sets the rules in the true/false + * list appropriately. If the result of the expression is undefined + * all of the rules are disabled for safety. + */ +static void evaluate_cond_node(struct policydb *p, struct cond_node *node) +{ + struct avtab_node *avnode; + int new_state; + u32 i; + + new_state = cond_evaluate_expr(p, &node->expr); + if (new_state != node->cur_state) { + node->cur_state = new_state; + if (new_state == -1) + pr_err("SELinux: expression result was undefined - disabling all rules.\n"); + /* turn the rules on or off */ + for (i = 0; i < node->true_list.len; i++) { + avnode = node->true_list.nodes[i]; + if (new_state <= 0) + avnode->key.specified &= ~AVTAB_ENABLED; + else + avnode->key.specified |= AVTAB_ENABLED; + } + + for (i = 0; i < node->false_list.len; i++) { + avnode = node->false_list.nodes[i]; + /* -1 or 1 */ + if (new_state) + avnode->key.specified &= ~AVTAB_ENABLED; + else + avnode->key.specified |= AVTAB_ENABLED; + } + } +} + +void evaluate_cond_nodes(struct policydb *p) +{ + u32 i; + + for (i = 0; i < p->cond_list_len; i++) + evaluate_cond_node(p, &p->cond_list[i]); +} + +void cond_policydb_init(struct policydb *p) +{ + p->bool_val_to_struct = NULL; + p->cond_list = NULL; + p->cond_list_len = 0; + + avtab_init(&p->te_cond_avtab); +} + +static void cond_node_destroy(struct cond_node *node) +{ + kfree(node->expr.nodes); + /* the avtab_ptr_t nodes are destroyed by the avtab */ + kfree(node->true_list.nodes); + kfree(node->false_list.nodes); +} + +static void cond_list_destroy(struct policydb *p) +{ + u32 i; + + for (i = 0; i < p->cond_list_len; i++) + cond_node_destroy(&p->cond_list[i]); + kfree(p->cond_list); + p->cond_list = NULL; + p->cond_list_len = 0; +} + +void cond_policydb_destroy(struct policydb *p) +{ + kfree(p->bool_val_to_struct); + avtab_destroy(&p->te_cond_avtab); + cond_list_destroy(p); +} + +int cond_init_bool_indexes(struct policydb *p) +{ + kfree(p->bool_val_to_struct); + p->bool_val_to_struct = kzalloc_objs(*p->bool_val_to_struct, + p->p_bools.nprim); + if (!p->bool_val_to_struct) + return -ENOMEM; + + avtab_hash_eval(&p->te_cond_avtab, "conditional_rules"); + + return 0; +} + +int cond_destroy_bool(void *key, void *datum, void *p) +{ + kfree(key); + kfree(datum); + return 0; +} + +int cond_index_bool(void *key, void *datum, void *datap) +{ + struct policydb *p; + struct cond_bool_datum *booldatum; + + booldatum = datum; + p = datap; + + if (!booldatum->value || booldatum->value > p->p_bools.nprim) + return -EINVAL; + + p->sym_val_to_name[SYM_BOOLS][booldatum->value - 1] = key; + p->bool_val_to_struct[booldatum->value - 1] = booldatum; + + return 0; +} + +int cond_read_bool(struct policydb *p, struct symtab *s, struct policy_file *fp) +{ + char *key = NULL; + struct cond_bool_datum *booldatum; + __le32 buf[3]; + u32 len, val; + int rc; + + booldatum = kzalloc_obj(*booldatum); + if (!booldatum) + return -ENOMEM; + + rc = next_entry(buf, fp, sizeof(buf)); + if (rc) + goto err; + + booldatum->value = le32_to_cpu(buf[0]); + val = le32_to_cpu(buf[1]); + + rc = -EINVAL; + if (!val_is_boolean(val)) + goto err; + booldatum->state = (int)val; + + len = le32_to_cpu(buf[2]); + + rc = str_read(&key, GFP_KERNEL, fp, len); + if (rc) + goto err; + + rc = symtab_insert(s, key, booldatum); + if (rc) + goto err; + + return 0; +err: + pr_err("SELinux: conditional: failed to read boolean\n"); + cond_destroy_bool(key, booldatum, NULL); + return rc; +} + +struct cond_insertf_data { + struct policydb *p; + struct avtab_node **dst; + struct cond_av_list *other; +}; + +static int cond_insertf(struct avtab *a, const struct avtab_key *k, + const struct avtab_datum *d, void *ptr) +{ + struct cond_insertf_data *data = ptr; + struct policydb *p = data->p; + struct cond_av_list *other = data->other; + struct avtab_node *node_ptr; + u32 i; + bool found; + + /* + * For type rules we have to make certain there aren't any + * conflicting rules by searching the te_avtab and the + * cond_te_avtab. + */ + if (k->specified & AVTAB_TYPE) { + if (avtab_search_node(&p->te_avtab, k)) { + pr_err("SELinux: type rule already exists outside of a conditional.\n"); + return -EINVAL; + } + /* + * If we are reading the false list other will be a pointer to + * the true list. We can have duplicate entries if there is only + * 1 other entry and it is in our true list. + * + * If we are reading the true list (other == NULL) there shouldn't + * be any other entries. + */ + if (other) { + node_ptr = avtab_search_node(&p->te_cond_avtab, k); + if (node_ptr) { + if (avtab_search_node_next(node_ptr, + k->specified)) { + pr_err("SELinux: too many conflicting type rules.\n"); + return -EINVAL; + } + found = false; + for (i = 0; i < other->len; i++) { + if (other->nodes[i] == node_ptr) { + found = true; + break; + } + } + if (!found) { + pr_err("SELinux: conflicting type rules.\n"); + return -EINVAL; + } + } + } else { + if (avtab_search_node(&p->te_cond_avtab, k)) { + pr_err("SELinux: conflicting type rules when adding type rule for true.\n"); + return -EINVAL; + } + } + } + + node_ptr = avtab_insert_nonunique(&p->te_cond_avtab, k, d); + if (!node_ptr) { + pr_err("SELinux: could not insert rule.\n"); + return -ENOMEM; + } + + *data->dst = node_ptr; + return 0; +} + +static int cond_read_av_list(struct policydb *p, struct policy_file *fp, + struct cond_av_list *list, + struct cond_av_list *other) +{ + int rc; + __le32 buf[1]; + u32 i, len; + struct cond_insertf_data data; + + rc = next_entry(buf, fp, sizeof(u32)); + if (rc) + return rc; + + len = le32_to_cpu(buf[0]); + if (len == 0) + return 0; + + /* avtab_read_item() reads at least 96 bytes for any valid entry */ + rc = size_check(3 * sizeof(u32), len, fp); + if (rc) + return rc; + + list->nodes = kzalloc_objs(*list->nodes, len); + if (!list->nodes) + return -ENOMEM; + + data.p = p; + data.other = other; + for (i = 0; i < len; i++) { + data.dst = &list->nodes[i]; + rc = avtab_read_item(&p->te_cond_avtab, fp, p, cond_insertf, + &data, true); + if (rc) { + kfree(list->nodes); + list->nodes = NULL; + return rc; + } + } + + list->len = len; + return 0; +} + +static int expr_node_isvalid(struct policydb *p, struct cond_expr_node *expr) +{ + if (expr->expr_type <= 0 || expr->expr_type > COND_LAST) { + pr_err("SELinux: conditional expressions uses unknown operator.\n"); + return 0; + } + + if (expr->expr_type == COND_BOOL && + (expr->boolean == 0 || expr->boolean > p->p_bools.nprim)) { + pr_err("SELinux: conditional expressions uses unknown bool.\n"); + return 0; + } + return 1; +} + +static int cond_read_node(struct policydb *p, struct cond_node *node, struct policy_file *fp) +{ + __le32 buf[2]; + u32 i, len; + int rc; + + rc = next_entry(buf, fp, sizeof(u32) * 2); + if (rc) + return rc; + + node->cur_state = le32_to_cpu(buf[0]); + + /* expr */ + len = le32_to_cpu(buf[1]); + + /* we will read 64 bytes per node */ + rc = size_check(2 * sizeof(u32), len, fp); + if (rc) + return rc; + + node->expr.nodes = kzalloc_objs(*node->expr.nodes, len); + if (!node->expr.nodes) + return -ENOMEM; + + node->expr.len = len; + + for (i = 0; i < len; i++) { + struct cond_expr_node *expr = &node->expr.nodes[i]; + + rc = next_entry(buf, fp, sizeof(u32) * 2); + if (rc) + return rc; + + expr->expr_type = le32_to_cpu(buf[0]); + expr->boolean = le32_to_cpu(buf[1]); + + if (!expr_node_isvalid(p, expr)) + return -EINVAL; + } + + rc = cond_read_av_list(p, fp, &node->true_list, NULL); + if (rc) + return rc; + return cond_read_av_list(p, fp, &node->false_list, &node->true_list); +} + +int cond_read_list(struct policydb *p, struct policy_file *fp) +{ + __le32 buf[1]; + u32 i, len; + int rc; + + rc = next_entry(buf, fp, sizeof(buf)); + if (rc) + return rc; + + len = le32_to_cpu(buf[0]); + + /* cond_read_node() reads at least 128 bytes for any valid node */ + rc = size_check(4 * sizeof(u32), len, fp); + if (rc) + return rc; + + p->cond_list = kzalloc_objs(*p->cond_list, len); + if (!p->cond_list) + return -ENOMEM; + + rc = avtab_alloc(&(p->te_cond_avtab), p->te_avtab.nel); + if (rc) + goto err; + + p->cond_list_len = len; + + for (i = 0; i < len; i++) { + rc = cond_read_node(p, &p->cond_list[i], fp); + if (rc) + goto err; + } + return 0; +err: + cond_list_destroy(p); + return rc; +} + +int cond_write_bool(void *vkey, void *datum, void *ptr) +{ + char *key = vkey; + struct cond_bool_datum *booldatum = datum; + struct policy_data *pd = ptr; + struct policy_file *fp = pd->fp; + __le32 buf[3]; + u32 len; + int rc; + + len = strlen(key); + buf[0] = cpu_to_le32(booldatum->value); + buf[1] = cpu_to_le32(booldatum->state); + buf[2] = cpu_to_le32(len); + rc = put_entry(buf, sizeof(u32), 3, fp); + if (rc) + return rc; + rc = put_entry(key, 1, len, fp); + if (rc) + return rc; + return 0; +} + +/* + * cond_write_cond_av_list doesn't write out the av_list nodes. + * Instead it writes out the key/value pairs from the avtab. This + * is necessary because there is no way to uniquely identifying rules + * in the avtab so it is not possible to associate individual rules + * in the avtab with a conditional without saving them as part of + * the conditional. This means that the avtab with the conditional + * rules will not be saved but will be rebuilt on policy load. + */ +static int cond_write_av_list(struct policydb *p, struct cond_av_list *list, + struct policy_file *fp) +{ + __le32 buf[1]; + u32 i; + int rc; + + buf[0] = cpu_to_le32(list->len); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + + for (i = 0; i < list->len; i++) { + rc = avtab_write_item(p, list->nodes[i], fp); + if (rc) + return rc; + } + + return 0; +} + +static int cond_write_node(struct policydb *p, struct cond_node *node, + struct policy_file *fp) +{ + __le32 buf[2]; + int rc; + u32 i; + + buf[0] = cpu_to_le32(node->cur_state); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + + buf[0] = cpu_to_le32(node->expr.len); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + + for (i = 0; i < node->expr.len; i++) { + buf[0] = cpu_to_le32(node->expr.nodes[i].expr_type); + buf[1] = cpu_to_le32(node->expr.nodes[i].boolean); + rc = put_entry(buf, sizeof(u32), 2, fp); + if (rc) + return rc; + } + + rc = cond_write_av_list(p, &node->true_list, fp); + if (rc) + return rc; + rc = cond_write_av_list(p, &node->false_list, fp); + if (rc) + return rc; + + return 0; +} + +int cond_write_list(struct policydb *p, struct policy_file *fp) +{ + u32 i; + __le32 buf[1]; + int rc; + + buf[0] = cpu_to_le32(p->cond_list_len); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + + for (i = 0; i < p->cond_list_len; i++) { + rc = cond_write_node(p, &p->cond_list[i], fp); + if (rc) + return rc; + } + + return 0; +} + +void cond_compute_xperms(struct avtab *ctab, struct avtab_key *key, + struct extended_perms_decision *xpermd) +{ + struct avtab_node *node; + + if (!ctab || !key || !xpermd) + return; + + for (node = avtab_search_node(ctab, key); node; + node = avtab_search_node_next(node, key->specified)) { + if (node->key.specified & AVTAB_ENABLED) + services_compute_xperms_decision(xpermd, node); + } +} +/* Determine whether additional permissions are granted by the conditional + * av table, and if so, add them to the result + */ +void cond_compute_av(struct avtab *ctab, struct avtab_key *key, + struct av_decision *avd, struct extended_perms *xperms) +{ + struct avtab_node *node; + + if (!ctab || !key || !avd) + return; + + for (node = avtab_search_node(ctab, key); node; + node = avtab_search_node_next(node, key->specified)) { + if ((u16)(AVTAB_ALLOWED | AVTAB_ENABLED) == + (node->key.specified & (AVTAB_ALLOWED | AVTAB_ENABLED))) + avd->allowed |= node->datum.u.data; + if ((u16)(AVTAB_AUDITDENY | AVTAB_ENABLED) == + (node->key.specified & (AVTAB_AUDITDENY | AVTAB_ENABLED))) + /* Since a '0' in an auditdeny mask represents a + * permission we do NOT want to audit (dontaudit), we use + * the '&' operand to ensure that all '0's in the mask + * are retained (much unlike the allow and auditallow cases). + */ + avd->auditdeny &= node->datum.u.data; + if ((u16)(AVTAB_AUDITALLOW | AVTAB_ENABLED) == + (node->key.specified & (AVTAB_AUDITALLOW | AVTAB_ENABLED))) + avd->auditallow |= node->datum.u.data; + if (xperms && (node->key.specified & AVTAB_ENABLED) && + (node->key.specified & AVTAB_XPERMS)) + services_compute_xperms_drivers(xperms, node); + } +} + +static int cond_dup_av_list(struct cond_av_list *new, + const struct cond_av_list *orig, + struct avtab *avtab) +{ + u32 i; + + memset(new, 0, sizeof(*new)); + + new->nodes = kzalloc_objs(*new->nodes, orig->len); + if (!new->nodes) + return -ENOMEM; + + for (i = 0; i < orig->len; i++) { + new->nodes[i] = avtab_insert_nonunique( + avtab, &orig->nodes[i]->key, &orig->nodes[i]->datum); + if (!new->nodes[i]) + return -ENOMEM; + new->len++; + } + + return 0; +} + +static int duplicate_policydb_cond_list(struct policydb *newp, + const struct policydb *origp) +{ + int rc; + u32 i; + + rc = avtab_alloc_dup(&newp->te_cond_avtab, &origp->te_cond_avtab); + if (rc) + return rc; + + newp->cond_list_len = 0; + newp->cond_list = kzalloc_objs(*newp->cond_list, origp->cond_list_len); + if (!newp->cond_list) + goto error; + + for (i = 0; i < origp->cond_list_len; i++) { + struct cond_node *newn = &newp->cond_list[i]; + const struct cond_node *orign = &origp->cond_list[i]; + + newp->cond_list_len++; + + newn->cur_state = orign->cur_state; + newn->expr.nodes = + kmemdup(orign->expr.nodes, + orign->expr.len * sizeof(*orign->expr.nodes), + GFP_KERNEL); + if (!newn->expr.nodes) + goto error; + + newn->expr.len = orign->expr.len; + + rc = cond_dup_av_list(&newn->true_list, &orign->true_list, + &newp->te_cond_avtab); + if (rc) + goto error; + + rc = cond_dup_av_list(&newn->false_list, &orign->false_list, + &newp->te_cond_avtab); + if (rc) + goto error; + } + + return 0; + +error: + avtab_destroy(&newp->te_cond_avtab); + cond_list_destroy(newp); + return -ENOMEM; +} + +static int cond_bools_destroy(void *key, void *datum, void *args) +{ + /* key was not copied so no need to free here */ + kfree(datum); + return 0; +} + +static int cond_bools_copy(struct hashtab_node *new, + const struct hashtab_node *orig, void *args) +{ + struct cond_bool_datum *datum; + + datum = kmemdup(orig->datum, sizeof(struct cond_bool_datum), + GFP_KERNEL); + if (!datum) + return -ENOMEM; + + new->key = orig->key; /* No need to copy, never modified */ + new->datum = datum; + return 0; +} + +static int cond_bools_index(void *key, void *datum, void *args) +{ + struct cond_bool_datum *booldatum, **cond_bool_array; + + booldatum = datum; + cond_bool_array = args; + cond_bool_array[booldatum->value - 1] = booldatum; + + return 0; +} + +static int duplicate_policydb_bools(struct policydb *newdb, + const struct policydb *orig) +{ + struct cond_bool_datum **cond_bool_array; + int rc; + + cond_bool_array = kzalloc_objs(*orig->bool_val_to_struct, + orig->p_bools.nprim); + if (!cond_bool_array) + return -ENOMEM; + + rc = hashtab_duplicate(&newdb->p_bools.table, &orig->p_bools.table, + cond_bools_copy, cond_bools_destroy, NULL); + if (rc) { + kfree(cond_bool_array); + return -ENOMEM; + } + + hashtab_map(&newdb->p_bools.table, cond_bools_index, cond_bool_array); + newdb->bool_val_to_struct = cond_bool_array; + + newdb->p_bools.nprim = orig->p_bools.nprim; + + return 0; +} + +void cond_policydb_destroy_dup(struct policydb *p) +{ + hashtab_map(&p->p_bools.table, cond_bools_destroy, NULL); + hashtab_destroy(&p->p_bools.table); + cond_policydb_destroy(p); +} + +int cond_policydb_dup(struct policydb *new, const struct policydb *orig) +{ + cond_policydb_init(new); + + if (duplicate_policydb_bools(new, orig)) + return -ENOMEM; + + if (duplicate_policydb_cond_list(new, orig)) { + cond_policydb_destroy_dup(new); + return -ENOMEM; + } + + return 0; +} diff --git a/security/selinux/ss/conditional.h b/security/selinux/ss/conditional.h new file mode 100644 index 000000000..468e98ad3 --- /dev/null +++ b/security/selinux/ss/conditional.h @@ -0,0 +1,84 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* Authors: Karl MacMillan <kmacmillan@tresys.com> + * Frank Mayer <mayerf@tresys.com> + * Copyright (C) 2003 - 2004 Tresys Technology, LLC + */ + +#ifndef _CONDITIONAL_H_ +#define _CONDITIONAL_H_ + +#include "avtab.h" +#include "symtab.h" +#include "policydb.h" +#include "../include/conditional.h" + +#define COND_EXPR_MAXDEPTH 10 + +/* + * A conditional expression is a list of operators and operands + * in reverse polish notation. + */ +struct cond_expr_node { +#define COND_BOOL 1 /* plain bool */ +#define COND_NOT 2 /* !bool */ +#define COND_OR 3 /* bool || bool */ +#define COND_AND 4 /* bool && bool */ +#define COND_XOR 5 /* bool ^ bool */ +#define COND_EQ 6 /* bool == bool */ +#define COND_NEQ 7 /* bool != bool */ +#define COND_LAST COND_NEQ + u32 expr_type; + u32 boolean; +}; + +struct cond_expr { + struct cond_expr_node *nodes; + u32 len; +}; + +/* + * Each cond_node contains a list of rules to be enabled/disabled + * depending on the current value of the conditional expression. This + * struct is for that list. + */ +struct cond_av_list { + struct avtab_node **nodes; + u32 len; +}; + +/* + * A cond node represents a conditional block in a policy. It + * contains a conditional expression, the current state of the expression, + * two lists of rules to enable/disable depending on the value of the + * expression (the true list corresponds to if and the false list corresponds + * to else).. + */ +struct cond_node { + int cur_state; + struct cond_expr expr; + struct cond_av_list true_list; + struct cond_av_list false_list; +}; + +void cond_policydb_init(struct policydb *p); +void cond_policydb_destroy(struct policydb *p); + +int cond_init_bool_indexes(struct policydb *p); +int cond_destroy_bool(void *key, void *datum, void *p); + +int cond_index_bool(void *key, void *datum, void *datap); + +int cond_read_bool(struct policydb *p, struct symtab *s, struct policy_file *fp); +int cond_read_list(struct policydb *p, struct policy_file *fp); +int cond_write_bool(void *key, void *datum, void *ptr); +int cond_write_list(struct policydb *p, struct policy_file *fp); + +void cond_compute_av(struct avtab *ctab, struct avtab_key *key, + struct av_decision *avd, struct extended_perms *xperms); +void cond_compute_xperms(struct avtab *ctab, struct avtab_key *key, + struct extended_perms_decision *xpermd); +void evaluate_cond_nodes(struct policydb *p); +void cond_policydb_destroy_dup(struct policydb *p); +int cond_policydb_dup(struct policydb *new, const struct policydb *orig); + +#endif /* _CONDITIONAL_H_ */ diff --git a/security/selinux/ss/constraint.h b/security/selinux/ss/constraint.h new file mode 100644 index 000000000..1d75a8a04 --- /dev/null +++ b/security/selinux/ss/constraint.h @@ -0,0 +1,65 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * A constraint is a condition that must be satisfied in + * order for one or more permissions to be granted. + * Constraints are used to impose additional restrictions + * beyond the type-based rules in `te' or the role-based + * transition rules in `rbac'. Constraints are typically + * used to prevent a process from transitioning to a new user + * identity or role unless it is in a privileged type. + * Constraints are likewise typically used to prevent a + * process from labeling an object with a different user + * identity. + * + * Author : Stephen Smalley, <stephen.smalley.work@gmail.com> + */ + +#ifndef _SS_CONSTRAINT_H_ +#define _SS_CONSTRAINT_H_ + +#include "ebitmap.h" + +#define CEXPR_MAXDEPTH 5 + +struct constraint_expr { +#define CEXPR_NOT 1 /* not expr */ +#define CEXPR_AND 2 /* expr and expr */ +#define CEXPR_OR 3 /* expr or expr */ +#define CEXPR_ATTR 4 /* attr op attr */ +#define CEXPR_NAMES 5 /* attr op names */ + u32 expr_type; /* expression type */ + +#define CEXPR_USER 1 /* user */ +#define CEXPR_ROLE 2 /* role */ +#define CEXPR_TYPE 4 /* type */ +#define CEXPR_TARGET 8 /* target if set, source otherwise */ +#define CEXPR_XTARGET 16 /* special 3rd target for validatetrans rule */ +#define CEXPR_L1L2 32 /* low level 1 vs. low level 2 */ +#define CEXPR_L1H2 64 /* low level 1 vs. high level 2 */ +#define CEXPR_H1L2 128 /* high level 1 vs. low level 2 */ +#define CEXPR_H1H2 256 /* high level 1 vs. high level 2 */ +#define CEXPR_L1H1 512 /* low level 1 vs. high level 1 */ +#define CEXPR_L2H2 1024 /* low level 2 vs. high level 2 */ + u32 attr; /* attribute */ + +#define CEXPR_EQ 1 /* == or eq */ +#define CEXPR_NEQ 2 /* != */ +#define CEXPR_DOM 3 /* dom */ +#define CEXPR_DOMBY 4 /* domby */ +#define CEXPR_INCOMP 5 /* incomp */ + u32 op; /* operator */ + + struct ebitmap names; /* names */ + /* internally unused, only forwarded via policydb_write() */ + struct type_set *type_names; + + struct constraint_expr *next; /* next expression */ +}; + +struct constraint_node { + u32 permissions; /* constrained permissions */ + struct constraint_expr *expr; /* constraint on permissions */ + struct constraint_node *next; /* next constraint */ +}; + +#endif /* _SS_CONSTRAINT_H_ */ diff --git a/security/selinux/ss/context.c b/security/selinux/ss/context.c new file mode 100644 index 000000000..a528b7f76 --- /dev/null +++ b/security/selinux/ss/context.c @@ -0,0 +1,32 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Implementations of the security context functions. + * + * Author: Ondrej Mosnacek <omosnacek@gmail.com> + * Copyright (C) 2020 Red Hat, Inc. + */ + +#include <linux/jhash.h> + +#include "context.h" +#include "mls.h" + +u32 context_compute_hash(const struct context *c) +{ + u32 hash = 0; + + /* + * If a context is invalid, it will always be represented by a + * context struct with only the len & str set (and vice versa) + * under a given policy. Since context structs from different + * policies should never meet, it is safe to hash valid and + * invalid contexts differently. The context_equal() function + * already operates under the same assumption. + */ + if (c->len) + return full_name_hash(NULL, c->str, c->len); + + hash = jhash_3words(c->user, c->role, c->type, hash); + hash = mls_range_hash(&c->range, hash); + return hash; +} diff --git a/security/selinux/ss/context.h b/security/selinux/ss/context.h new file mode 100644 index 000000000..dd3b9b5b5 --- /dev/null +++ b/security/selinux/ss/context.h @@ -0,0 +1,204 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * A security context is a set of security attributes + * associated with each subject and object controlled + * by the security policy. Security contexts are + * externally represented as variable-length strings + * that can be interpreted by a user or application + * with an understanding of the security policy. + * Internally, the security server uses a simple + * structure. This structure is private to the + * security server and can be changed without affecting + * clients of the security server. + * + * Author : Stephen Smalley, <stephen.smalley.work@gmail.com> + */ + +#ifndef _SS_CONTEXT_H_ +#define _SS_CONTEXT_H_ + +#include "ebitmap.h" +#include "mls_types.h" +#include "security.h" + +/* + * A security context consists of an authenticated user + * identity, a role, a type and a MLS range. + */ +struct context { + u32 user; + u32 role; + u32 type; + u32 len; /* length of string in bytes */ + struct mls_range range; + char *str; /* string representation if context cannot be mapped. */ +}; + +static inline void mls_context_init(struct context *c) +{ + memset(&c->range, 0, sizeof(c->range)); +} + +static inline int mls_context_cpy(struct context *dst, + const struct context *src) +{ + int rc; + + dst->range.level[0].sens = src->range.level[0].sens; + rc = ebitmap_cpy(&dst->range.level[0].cat, &src->range.level[0].cat); + if (rc) + goto out; + + dst->range.level[1].sens = src->range.level[1].sens; + rc = ebitmap_cpy(&dst->range.level[1].cat, &src->range.level[1].cat); + if (rc) + ebitmap_destroy(&dst->range.level[0].cat); +out: + return rc; +} + +/* + * Sets both levels in the MLS range of 'dst' to the low level of 'src'. + */ +static inline int mls_context_cpy_low(struct context *dst, + const struct context *src) +{ + int rc; + + dst->range.level[0].sens = src->range.level[0].sens; + rc = ebitmap_cpy(&dst->range.level[0].cat, &src->range.level[0].cat); + if (rc) + goto out; + + dst->range.level[1].sens = src->range.level[0].sens; + rc = ebitmap_cpy(&dst->range.level[1].cat, &src->range.level[0].cat); + if (rc) + ebitmap_destroy(&dst->range.level[0].cat); +out: + return rc; +} + +/* + * Sets both levels in the MLS range of 'dst' to the high level of 'src'. + */ +static inline int mls_context_cpy_high(struct context *dst, + const struct context *src) +{ + int rc; + + dst->range.level[0].sens = src->range.level[1].sens; + rc = ebitmap_cpy(&dst->range.level[0].cat, &src->range.level[1].cat); + if (rc) + goto out; + + dst->range.level[1].sens = src->range.level[1].sens; + rc = ebitmap_cpy(&dst->range.level[1].cat, &src->range.level[1].cat); + if (rc) + ebitmap_destroy(&dst->range.level[0].cat); +out: + return rc; +} + +static inline int mls_context_glblub(struct context *dst, + const struct context *c1, + const struct context *c2) +{ + struct mls_range *dr = &dst->range; + const struct mls_range *r1 = &c1->range, *r2 = &c2->range; + int rc = 0; + + if (r1->level[1].sens < r2->level[0].sens || + r2->level[1].sens < r1->level[0].sens) + /* These ranges have no common sensitivities */ + return -EINVAL; + + /* Take the greatest of the low */ + dr->level[0].sens = max(r1->level[0].sens, r2->level[0].sens); + + /* Take the least of the high */ + dr->level[1].sens = min(r1->level[1].sens, r2->level[1].sens); + + rc = ebitmap_and(&dr->level[0].cat, &r1->level[0].cat, + &r2->level[0].cat); + if (rc) + goto out; + + rc = ebitmap_and(&dr->level[1].cat, &r1->level[1].cat, + &r2->level[1].cat); + if (rc) + goto out; + +out: + return rc; +} + +static inline bool mls_context_equal(const struct context *c1, + const struct context *c2) +{ + return ((c1->range.level[0].sens == c2->range.level[0].sens) && + ebitmap_equal(&c1->range.level[0].cat, &c2->range.level[0].cat) && + (c1->range.level[1].sens == c2->range.level[1].sens) && + ebitmap_equal(&c1->range.level[1].cat, &c2->range.level[1].cat)); +} + +static inline void mls_context_destroy(struct context *c) +{ + ebitmap_destroy(&c->range.level[0].cat); + ebitmap_destroy(&c->range.level[1].cat); + mls_context_init(c); +} + +static inline void context_init(struct context *c) +{ + memset(c, 0, sizeof(*c)); +} + +static inline int context_cpy(struct context *dst, const struct context *src) +{ + int rc; + + dst->user = src->user; + dst->role = src->role; + dst->type = src->type; + if (src->str) { + dst->str = kstrdup(src->str, GFP_ATOMIC); + if (!dst->str) + return -ENOMEM; + dst->len = src->len; + } else { + dst->str = NULL; + dst->len = 0; + } + rc = mls_context_cpy(dst, src); + if (rc) { + kfree(dst->str); + dst->str = NULL; + dst->len = 0; + return rc; + } + return 0; +} + +static inline void context_destroy(struct context *c) +{ + c->user = c->role = c->type = 0; + kfree(c->str); + c->str = NULL; + c->len = 0; + mls_context_destroy(c); +} + +static inline bool context_equal(const struct context *c1, + const struct context *c2) +{ + if (c1->len && c2->len) + return (c1->len == c2->len && !strcmp(c1->str, c2->str)); + if (c1->len || c2->len) + return 0; + return ((c1->user == c2->user) && (c1->role == c2->role) && + (c1->type == c2->type) && mls_context_equal(c1, c2)); +} + +u32 context_compute_hash(const struct context *c); + +#endif /* _SS_CONTEXT_H_ */ diff --git a/security/selinux/ss/ebitmap.c b/security/selinux/ss/ebitmap.c new file mode 100644 index 000000000..ea894361f --- /dev/null +++ b/security/selinux/ss/ebitmap.c @@ -0,0 +1,603 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Implementation of the extensible bitmap type. + * + * Author : Stephen Smalley, <stephen.smalley.work@gmail.com> + */ +/* + * Updated: Hewlett-Packard <paul@paul-moore.com> + * Added support to import/export the NetLabel category bitmap + * (c) Copyright Hewlett-Packard Development Company, L.P., 2006 + * + * Updated: KaiGai Kohei <kaigai@ak.jp.nec.com> + * Applied standard bit operations to improve bitmap scanning. + */ + +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/errno.h> +#include <linux/jhash.h> +#include <net/netlabel.h> +#include "ebitmap.h" +#include "policydb.h" + +#define BITS_PER_U64 ((u32)(sizeof(u64) * 8)) + +static struct kmem_cache *ebitmap_node_cachep __ro_after_init; + +bool ebitmap_equal(const struct ebitmap *e1, const struct ebitmap *e2) +{ + const struct ebitmap_node *n1, *n2; + + if (e1->highbit != e2->highbit) + return false; + + n1 = e1->node; + n2 = e2->node; + while (n1 && n2 && (n1->startbit == n2->startbit) && + !memcmp(n1->maps, n2->maps, EBITMAP_SIZE / 8)) { + n1 = n1->next; + n2 = n2->next; + } + + if (n1 || n2) + return false; + + return true; +} + +int ebitmap_cpy(struct ebitmap *dst, const struct ebitmap *src) +{ + struct ebitmap_node *new, *prev; + const struct ebitmap_node *n; + + ebitmap_init(dst); + n = src->node; + prev = NULL; + while (n) { + new = kmem_cache_zalloc(ebitmap_node_cachep, GFP_ATOMIC); + if (!new) { + ebitmap_destroy(dst); + return -ENOMEM; + } + new->startbit = n->startbit; + memcpy(new->maps, n->maps, EBITMAP_SIZE / 8); + new->next = NULL; + if (prev) + prev->next = new; + else + dst->node = new; + prev = new; + n = n->next; + } + + dst->highbit = src->highbit; + return 0; +} + +int ebitmap_and(struct ebitmap *dst, const struct ebitmap *e1, + const struct ebitmap *e2) +{ + struct ebitmap_node *n; + u32 bit; + int rc; + + ebitmap_init(dst); + + ebitmap_for_each_positive_bit(e1, n, bit) + { + if (ebitmap_get_bit(e2, bit)) { + rc = ebitmap_set_bit(dst, bit, 1); + if (rc < 0) + return rc; + } + } + return 0; +} + +#ifdef CONFIG_NETLABEL +/** + * ebitmap_netlbl_export - Export an ebitmap into a NetLabel category bitmap + * @ebmap: the ebitmap to export + * @catmap: the NetLabel category bitmap + * + * Description: + * Export a SELinux extensibile bitmap into a NetLabel category bitmap. + * Returns zero on success, negative values on error. + * + */ +int ebitmap_netlbl_export(struct ebitmap *ebmap, + struct netlbl_lsm_catmap **catmap) +{ + struct ebitmap_node *e_iter = ebmap->node; + unsigned long e_map; + u32 offset; + unsigned int iter; + int rc; + + if (e_iter == NULL) { + *catmap = NULL; + return 0; + } + + if (*catmap != NULL) + netlbl_catmap_free(*catmap); + *catmap = NULL; + + while (e_iter) { + offset = e_iter->startbit; + for (iter = 0; iter < EBITMAP_UNIT_NUMS; iter++) { + e_map = e_iter->maps[iter]; + if (e_map != 0) { + rc = netlbl_catmap_setlong(catmap, offset, + e_map, GFP_ATOMIC); + if (rc != 0) + goto netlbl_export_failure; + } + offset += EBITMAP_UNIT_SIZE; + } + e_iter = e_iter->next; + } + + return 0; + +netlbl_export_failure: + netlbl_catmap_free(*catmap); + return -ENOMEM; +} + +/** + * ebitmap_netlbl_import - Import a NetLabel category bitmap into an ebitmap + * @ebmap: the ebitmap to import + * @catmap: the NetLabel category bitmap + * + * Description: + * Import a NetLabel category bitmap into a SELinux extensibile bitmap. + * Returns zero on success, negative values on error. + * + */ +int ebitmap_netlbl_import(struct ebitmap *ebmap, + struct netlbl_lsm_catmap *catmap) +{ + int rc; + struct ebitmap_node *e_iter = NULL; + struct ebitmap_node *e_prev = NULL; + u32 offset = 0, idx; + unsigned long bitmap; + + for (;;) { + rc = netlbl_catmap_getlong(catmap, &offset, &bitmap); + if (rc < 0) + goto netlbl_import_failure; + if (offset == (u32)-1) + return 0; + + /* don't waste ebitmap space if the netlabel bitmap is empty */ + if (bitmap == 0) { + offset += EBITMAP_UNIT_SIZE; + continue; + } + + if (e_iter == NULL || + offset >= e_iter->startbit + EBITMAP_SIZE) { + e_prev = e_iter; + e_iter = kmem_cache_zalloc(ebitmap_node_cachep, + GFP_ATOMIC); + if (e_iter == NULL) + goto netlbl_import_failure; + e_iter->startbit = offset - (offset % EBITMAP_SIZE); + if (e_prev == NULL) + ebmap->node = e_iter; + else + e_prev->next = e_iter; + ebmap->highbit = e_iter->startbit + EBITMAP_SIZE; + } + + /* offset will always be aligned to an unsigned long */ + idx = EBITMAP_NODE_INDEX(e_iter, offset); + e_iter->maps[idx] = bitmap; + + /* next */ + offset += EBITMAP_UNIT_SIZE; + } + + /* NOTE: we should never reach this return */ + return 0; + +netlbl_import_failure: + ebitmap_destroy(ebmap); + return -ENOMEM; +} +#endif /* CONFIG_NETLABEL */ + +/* + * Check to see if all the bits set in e2 are also set in e1. Optionally, + * if last_e2bit is non-zero, the highest set bit in e2 cannot exceed + * last_e2bit. + */ +int ebitmap_contains(const struct ebitmap *e1, const struct ebitmap *e2, + u32 last_e2bit) +{ + const struct ebitmap_node *n1, *n2; + int i; + + if (e1->highbit < e2->highbit) + return 0; + + n1 = e1->node; + n2 = e2->node; + + while (n1 && n2 && (n1->startbit <= n2->startbit)) { + if (n1->startbit < n2->startbit) { + n1 = n1->next; + continue; + } + for (i = EBITMAP_UNIT_NUMS - 1; (i >= 0) && !n2->maps[i];) + i--; /* Skip trailing NULL map entries */ + if (last_e2bit && (i >= 0)) { + u32 lastsetbit = n2->startbit + i * EBITMAP_UNIT_SIZE + + __fls(n2->maps[i]); + if (lastsetbit > last_e2bit) + return 0; + } + + while (i >= 0) { + if ((n1->maps[i] & n2->maps[i]) != n2->maps[i]) + return 0; + i--; + } + + n1 = n1->next; + n2 = n2->next; + } + + if (n2) + return 0; + + return 1; +} + +u32 ebitmap_get_highest_set_bit(const struct ebitmap *e) +{ + const struct ebitmap_node *n; + unsigned long unit; + u32 pos = 0; + + n = e->node; + if (!n) + return 0; + + while (n->next) + n = n->next; + + for (unsigned int i = EBITMAP_UNIT_NUMS; i > 0; i--) { + unit = n->maps[i - 1]; + if (unit == 0) + continue; + + pos = (i - 1) * EBITMAP_UNIT_SIZE; + while (unit >>= 1) + pos++; + break; + } + + return n->startbit + pos; +} + +int ebitmap_get_bit(const struct ebitmap *e, u32 bit) +{ + const struct ebitmap_node *n; + + if (e->highbit < bit) + return 0; + + n = e->node; + while (n && (n->startbit <= bit)) { + if ((n->startbit + EBITMAP_SIZE) > bit) + return ebitmap_node_get_bit(n, bit); + n = n->next; + } + + return 0; +} + +int ebitmap_set_bit(struct ebitmap *e, u32 bit, int value) +{ + struct ebitmap_node *n, *prev, *new; + + prev = NULL; + n = e->node; + while (n && n->startbit <= bit) { + if ((n->startbit + EBITMAP_SIZE) > bit) { + if (value) { + ebitmap_node_set_bit(n, bit); + } else { + u32 s; + + ebitmap_node_clr_bit(n, bit); + + s = find_first_bit(n->maps, EBITMAP_SIZE); + if (s < EBITMAP_SIZE) + return 0; + + /* drop this node from the bitmap */ + if (!n->next) { + /* + * this was the highest map + * within the bitmap + */ + if (prev) + e->highbit = prev->startbit + + EBITMAP_SIZE; + else + e->highbit = 0; + } + if (prev) + prev->next = n->next; + else + e->node = n->next; + kmem_cache_free(ebitmap_node_cachep, n); + } + return 0; + } + prev = n; + n = n->next; + } + + if (!value) + return 0; + + new = kmem_cache_zalloc(ebitmap_node_cachep, GFP_ATOMIC); + if (!new) + return -ENOMEM; + + new->startbit = bit - (bit % EBITMAP_SIZE); + ebitmap_node_set_bit(new, bit); + + if (!n) + /* this node will be the highest map within the bitmap */ + e->highbit = new->startbit + EBITMAP_SIZE; + + if (prev) { + new->next = prev->next; + prev->next = new; + } else { + new->next = e->node; + e->node = new; + } + + return 0; +} + +void ebitmap_destroy(struct ebitmap *e) +{ + struct ebitmap_node *n, *temp; + + if (!e) + return; + + n = e->node; + while (n) { + temp = n; + n = n->next; + kmem_cache_free(ebitmap_node_cachep, temp); + } + + e->highbit = 0; + e->node = NULL; +} + +int ebitmap_read(struct ebitmap *e, struct policy_file *fp) +{ + struct ebitmap_node *n = NULL; + u32 mapunit, count, startbit, index, i; + __le32 ebitmap_start; + u64 map; + __le64 mapbits; + __le32 buf[3]; + int rc; + + ebitmap_init(e); + + rc = next_entry(buf, fp, sizeof buf); + if (rc < 0) + goto out; + + mapunit = le32_to_cpu(buf[0]); + e->highbit = le32_to_cpu(buf[1]); + count = le32_to_cpu(buf[2]); + + if (mapunit != BITS_PER_U64) { + pr_err("SELinux: ebitmap: map size %u does not " + "match my size %u (high bit was %u)\n", + mapunit, BITS_PER_U64, e->highbit); + goto bad; + } + + /* round up e->highbit */ + e->highbit += EBITMAP_SIZE - 1; + e->highbit -= (e->highbit % EBITMAP_SIZE); + + if (!e->highbit) { + e->node = NULL; + goto ok; + } + + if (e->highbit && !count) + goto bad; + + for (i = 0; i < count; i++) { + rc = next_entry(&ebitmap_start, fp, sizeof(u32)); + if (rc < 0) { + pr_err("SELinux: ebitmap: truncated map\n"); + goto bad; + } + startbit = le32_to_cpu(ebitmap_start); + + if (startbit & (mapunit - 1)) { + pr_err("SELinux: ebitmap start bit (%u) is " + "not a multiple of the map unit size (%u)\n", + startbit, mapunit); + goto bad; + } + if (startbit > e->highbit - mapunit) { + pr_err("SELinux: ebitmap start bit (%u) is " + "beyond the end of the bitmap (%u)\n", + startbit, (e->highbit - mapunit)); + goto bad; + } + + if (!n || startbit >= n->startbit + EBITMAP_SIZE) { + struct ebitmap_node *tmp; + tmp = kmem_cache_zalloc(ebitmap_node_cachep, + GFP_KERNEL); + if (!tmp) { + pr_err("SELinux: ebitmap: out of memory\n"); + rc = -ENOMEM; + goto bad; + } + /* round down */ + tmp->startbit = startbit - (startbit % EBITMAP_SIZE); + if (n) + n->next = tmp; + else + e->node = tmp; + n = tmp; + } else if (startbit <= n->startbit) { + pr_err("SELinux: ebitmap: start bit %u" + " comes after start bit %u\n", + startbit, n->startbit); + goto bad; + } + + rc = next_entry(&mapbits, fp, sizeof(u64)); + if (rc < 0) { + pr_err("SELinux: ebitmap: truncated map\n"); + goto bad; + } + map = le64_to_cpu(mapbits); + if (!map) { + pr_err("SELinux: ebitmap: empty map\n"); + goto bad; + } + + index = (startbit - n->startbit) / EBITMAP_UNIT_SIZE; + while (map) { + n->maps[index++] = map & (-1UL); + map = EBITMAP_SHIFT_UNIT_SIZE(map); + } + } + + if (n && n->startbit + EBITMAP_SIZE != e->highbit) { + pr_err("SELinux: ebitmap: high bit %u is not equal to the expected value %zu\n", + e->highbit, n->startbit + EBITMAP_SIZE); + goto bad; + } + +ok: + rc = 0; +out: + return rc; +bad: + if (!rc) + rc = -EINVAL; + ebitmap_destroy(e); + goto out; +} + +int ebitmap_write(const struct ebitmap *e, struct policy_file *fp) +{ + struct ebitmap_node *n; + u32 bit, count, last_bit, last_startbit; + __le32 buf[3]; + u64 map; + int rc; + + buf[0] = cpu_to_le32(BITS_PER_U64); + + count = 0; + last_bit = 0; + last_startbit = U32_MAX; + ebitmap_for_each_positive_bit(e, n, bit) + { + if (last_startbit == U32_MAX || + rounddown(bit, BITS_PER_U64) > last_startbit) { + count++; + last_startbit = rounddown(bit, BITS_PER_U64); + } + last_bit = roundup(bit + 1, BITS_PER_U64); + } + buf[1] = cpu_to_le32(last_bit); + buf[2] = cpu_to_le32(count); + + rc = put_entry(buf, sizeof(u32), 3, fp); + if (rc) + return rc; + + map = 0; + last_startbit = U32_MAX; + ebitmap_for_each_positive_bit(e, n, bit) + { + if (last_startbit == U32_MAX || + rounddown(bit, BITS_PER_U64) > last_startbit) { + __le64 buf64[1]; + + /* this is the very first bit */ + if (!map) { + last_startbit = rounddown(bit, BITS_PER_U64); + map = (u64)1 << (bit - last_startbit); + continue; + } + + /* write the last node */ + buf[0] = cpu_to_le32(last_startbit); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + + buf64[0] = cpu_to_le64(map); + rc = put_entry(buf64, sizeof(u64), 1, fp); + if (rc) + return rc; + + /* set up for the next node */ + map = 0; + last_startbit = rounddown(bit, BITS_PER_U64); + } + map |= (u64)1 << (bit - last_startbit); + } + /* write the last node */ + if (map) { + __le64 buf64[1]; + + /* write the last node */ + buf[0] = cpu_to_le32(last_startbit); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + + buf64[0] = cpu_to_le64(map); + rc = put_entry(buf64, sizeof(u64), 1, fp); + if (rc) + return rc; + } + return 0; +} + +u32 ebitmap_hash(const struct ebitmap *e, u32 hash) +{ + struct ebitmap_node *node; + + /* need to change hash even if ebitmap is empty */ + hash = jhash_1word(e->highbit, hash); + for (node = e->node; node; node = node->next) { + hash = jhash_1word(node->startbit, hash); + hash = jhash(node->maps, sizeof(node->maps), hash); + } + return hash; +} + +void __init ebitmap_cache_init(void) +{ + ebitmap_node_cachep = KMEM_CACHE(ebitmap_node, SLAB_PANIC); +} diff --git a/security/selinux/ss/ebitmap.h b/security/selinux/ss/ebitmap.h new file mode 100644 index 000000000..ae05cc8e4 --- /dev/null +++ b/security/selinux/ss/ebitmap.h @@ -0,0 +1,156 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * An extensible bitmap is a bitmap that supports an + * arbitrary number of bits. Extensible bitmaps are + * used to represent sets of values, such as types, + * roles, categories, and classes. + * + * Each extensible bitmap is implemented as a linked + * list of bitmap nodes, where each bitmap node has + * an explicitly specified starting bit position within + * the total bitmap. + * + * Author : Stephen Smalley, <stephen.smalley.work@gmail.com> + */ + +#ifndef _SS_EBITMAP_H_ +#define _SS_EBITMAP_H_ + +#include <net/netlabel.h> + +#ifdef CONFIG_64BIT +#define EBITMAP_NODE_SIZE 64 +#else +#define EBITMAP_NODE_SIZE 32 +#endif + +#define EBITMAP_UNIT_NUMS \ + ((EBITMAP_NODE_SIZE - sizeof(void *) - sizeof(u32)) / \ + sizeof(unsigned long)) +#define EBITMAP_UNIT_SIZE BITS_PER_LONG +#define EBITMAP_SIZE (EBITMAP_UNIT_NUMS * EBITMAP_UNIT_SIZE) +#define EBITMAP_BIT 1UL +#define EBITMAP_SHIFT_UNIT_SIZE(x) \ + (((x) >> EBITMAP_UNIT_SIZE / 2) >> EBITMAP_UNIT_SIZE / 2) + +struct ebitmap_node { + struct ebitmap_node *next; + unsigned long maps[EBITMAP_UNIT_NUMS]; + u32 startbit; +}; + +struct ebitmap { + struct ebitmap_node *node; /* first node in the bitmap */ + u32 highbit; /* highest position in the total bitmap */ +}; + +#define ebitmap_length(e) ((e)->highbit) + +static inline u32 ebitmap_start_positive(const struct ebitmap *e, + struct ebitmap_node **n) +{ + u32 ofs; + + for (*n = e->node; *n; *n = (*n)->next) { + ofs = find_first_bit((*n)->maps, EBITMAP_SIZE); + if (ofs < EBITMAP_SIZE) + return (*n)->startbit + ofs; + } + return ebitmap_length(e); +} + +static inline void ebitmap_init(struct ebitmap *e) +{ + memset(e, 0, sizeof(*e)); +} + +static inline u32 ebitmap_next_positive(const struct ebitmap *e, + struct ebitmap_node **n, u32 bit) +{ + u32 ofs; + + ofs = find_next_bit((*n)->maps, EBITMAP_SIZE, bit - (*n)->startbit + 1); + if (ofs < EBITMAP_SIZE) + return ofs + (*n)->startbit; + + for (*n = (*n)->next; *n; *n = (*n)->next) { + ofs = find_first_bit((*n)->maps, EBITMAP_SIZE); + if (ofs < EBITMAP_SIZE) + return ofs + (*n)->startbit; + } + return ebitmap_length(e); +} + +#define EBITMAP_NODE_INDEX(node, bit) \ + (((bit) - (node)->startbit) / EBITMAP_UNIT_SIZE) +#define EBITMAP_NODE_OFFSET(node, bit) \ + (((bit) - (node)->startbit) % EBITMAP_UNIT_SIZE) + +static inline int ebitmap_node_get_bit(const struct ebitmap_node *n, u32 bit) +{ + u32 index = EBITMAP_NODE_INDEX(n, bit); + u32 ofs = EBITMAP_NODE_OFFSET(n, bit); + + BUG_ON(index >= EBITMAP_UNIT_NUMS); + if ((n->maps[index] & (EBITMAP_BIT << ofs))) + return 1; + return 0; +} + +static inline void ebitmap_node_set_bit(struct ebitmap_node *n, u32 bit) +{ + u32 index = EBITMAP_NODE_INDEX(n, bit); + u32 ofs = EBITMAP_NODE_OFFSET(n, bit); + + BUG_ON(index >= EBITMAP_UNIT_NUMS); + n->maps[index] |= (EBITMAP_BIT << ofs); +} + +static inline void ebitmap_node_clr_bit(struct ebitmap_node *n, u32 bit) +{ + u32 index = EBITMAP_NODE_INDEX(n, bit); + u32 ofs = EBITMAP_NODE_OFFSET(n, bit); + + BUG_ON(index >= EBITMAP_UNIT_NUMS); + n->maps[index] &= ~(EBITMAP_BIT << ofs); +} + +#define ebitmap_for_each_positive_bit(e, n, bit) \ + for ((bit) = ebitmap_start_positive(e, &(n)); \ + (bit) < ebitmap_length(e); \ + (bit) = ebitmap_next_positive(e, &(n), bit)) + +bool ebitmap_equal(const struct ebitmap *e1, const struct ebitmap *e2); +int ebitmap_cpy(struct ebitmap *dst, const struct ebitmap *src); +int ebitmap_and(struct ebitmap *dst, const struct ebitmap *e1, + const struct ebitmap *e2); +int ebitmap_contains(const struct ebitmap *e1, const struct ebitmap *e2, + u32 last_e2bit); +u32 ebitmap_get_highest_set_bit(const struct ebitmap *e); +int ebitmap_get_bit(const struct ebitmap *e, u32 bit); +int ebitmap_set_bit(struct ebitmap *e, u32 bit, int value); +void ebitmap_destroy(struct ebitmap *e); +struct policy_file; +int ebitmap_read(struct ebitmap *e, struct policy_file *fp); +int ebitmap_write(const struct ebitmap *e, struct policy_file *fp); +u32 ebitmap_hash(const struct ebitmap *e, u32 hash); + +#ifdef CONFIG_NETLABEL +int ebitmap_netlbl_export(struct ebitmap *ebmap, + struct netlbl_lsm_catmap **catmap); +int ebitmap_netlbl_import(struct ebitmap *ebmap, + struct netlbl_lsm_catmap *catmap); +#else +static inline int ebitmap_netlbl_export(struct ebitmap *ebmap, + struct netlbl_lsm_catmap **catmap) +{ + return -ENOMEM; +} +static inline int ebitmap_netlbl_import(struct ebitmap *ebmap, + struct netlbl_lsm_catmap *catmap) +{ + return -ENOMEM; +} +#endif + +#endif /* _SS_EBITMAP_H_ */ diff --git a/security/selinux/ss/hashtab.c b/security/selinux/ss/hashtab.c new file mode 100644 index 000000000..9ffc8a371 --- /dev/null +++ b/security/selinux/ss/hashtab.c @@ -0,0 +1,199 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Implementation of the hash table type. + * + * Author : Stephen Smalley, <stephen.smalley.work@gmail.com> + */ + +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/errno.h> +#include "hashtab.h" +#include "security.h" + +static struct kmem_cache *hashtab_node_cachep __ro_after_init; + +/* + * Here we simply round the number of elements up to the nearest power of two. + * I tried also other options like rounding down or rounding to the closest + * power of two (up or down based on which is closer), but I was unable to + * find any significant difference in lookup/insert performance that would + * justify switching to a different (less intuitive) formula. It could be that + * a different formula is actually more optimal, but any future changes here + * should be supported with performance/memory usage data. + * + * The total memory used by the htable arrays (only) with Fedora policy loaded + * is approximately 163 KB at the time of writing. + */ +static u32 hashtab_compute_size(u32 nel) +{ + return nel == 0 ? 0 : roundup_pow_of_two(nel); +} + +int hashtab_init(struct hashtab *h, u32 nel_hint) +{ + u32 size = hashtab_compute_size(nel_hint); + + /* should already be zeroed, but better be safe */ + h->nel = 0; + h->size = 0; + h->htable = NULL; + + if (size) { + h->htable = kzalloc_objs(*h->htable, size, + GFP_KERNEL | __GFP_NOWARN); + if (!h->htable) + return -ENOMEM; + h->size = size; + } + return 0; +} + +int __hashtab_insert(struct hashtab *h, struct hashtab_node **dst, void *key, + void *datum) +{ + struct hashtab_node *newnode; + + newnode = kmem_cache_zalloc(hashtab_node_cachep, GFP_KERNEL); + if (!newnode) + return -ENOMEM; + newnode->key = key; + newnode->datum = datum; + newnode->next = *dst; + *dst = newnode; + + h->nel++; + return 0; +} + +void hashtab_destroy(struct hashtab *h) +{ + u32 i; + struct hashtab_node *cur, *temp; + + for (i = 0; i < h->size; i++) { + cur = h->htable[i]; + while (cur) { + temp = cur; + cur = cur->next; + kmem_cache_free(hashtab_node_cachep, temp); + } + h->htable[i] = NULL; + } + + kfree(h->htable); + h->htable = NULL; +} + +int hashtab_map(struct hashtab *h, int (*apply)(void *k, void *d, void *args), + void *args) +{ + u32 i; + int ret; + struct hashtab_node *cur; + + for (i = 0; i < h->size; i++) { + cur = h->htable[i]; + while (cur) { + ret = apply(cur->key, cur->datum, args); + if (ret) + return ret; + cur = cur->next; + } + } + return 0; +} + +#ifdef CONFIG_SECURITY_SELINUX_DEBUG +void hashtab_stat(struct hashtab *h, struct hashtab_info *info) +{ + u32 i, chain_len, slots_used, max_chain_len; + u64 chain2_len_sum; + struct hashtab_node *cur; + + slots_used = 0; + max_chain_len = 0; + chain2_len_sum = 0; + for (i = 0; i < h->size; i++) { + cur = h->htable[i]; + if (cur) { + slots_used++; + chain_len = 0; + while (cur) { + chain_len++; + cur = cur->next; + } + + if (chain_len > max_chain_len) + max_chain_len = chain_len; + + chain2_len_sum += (u64)chain_len * chain_len; + } + } + + info->slots_used = slots_used; + info->max_chain_len = max_chain_len; + info->chain2_len_sum = chain2_len_sum; +} +#endif /* CONFIG_SECURITY_SELINUX_DEBUG */ + +int hashtab_duplicate(struct hashtab *new, const struct hashtab *orig, + int (*copy)(struct hashtab_node *new, + const struct hashtab_node *orig, void *args), + int (*destroy)(void *k, void *d, void *args), void *args) +{ + const struct hashtab_node *orig_cur; + struct hashtab_node *cur, *tmp, *tail; + u32 i; + int rc; + + memset(new, 0, sizeof(*new)); + + new->htable = kzalloc_objs(*new->htable, orig->size); + if (!new->htable) + return -ENOMEM; + + new->size = orig->size; + + for (i = 0; i < orig->size; i++) { + tail = NULL; + for (orig_cur = orig->htable[i]; orig_cur; + orig_cur = orig_cur->next) { + tmp = kmem_cache_zalloc(hashtab_node_cachep, + GFP_KERNEL); + if (!tmp) + goto error; + rc = copy(tmp, orig_cur, args); + if (rc) { + kmem_cache_free(hashtab_node_cachep, tmp); + goto error; + } + tmp->next = NULL; + if (!tail) + new->htable[i] = tmp; + else + tail->next = tmp; + tail = tmp; + new->nel++; + } + } + + return 0; + +error: + for (i = 0; i < new->size; i++) { + for (cur = new->htable[i]; cur; cur = tmp) { + tmp = cur->next; + destroy(cur->key, cur->datum, args); + kmem_cache_free(hashtab_node_cachep, cur); + } + } + kfree(new->htable); + memset(new, 0, sizeof(*new)); + return -ENOMEM; +} + +void __init hashtab_cache_init(void) +{ + hashtab_node_cachep = KMEM_CACHE(hashtab_node, SLAB_PANIC); +} diff --git a/security/selinux/ss/hashtab.h b/security/selinux/ss/hashtab.h new file mode 100644 index 000000000..c641fb129 --- /dev/null +++ b/security/selinux/ss/hashtab.h @@ -0,0 +1,154 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * A hash table (hashtab) maintains associations between + * key values and datum values. The type of the key values + * and the type of the datum values is arbitrary. The + * functions for hash computation and key comparison are + * provided by the creator of the table. + * + * Author : Stephen Smalley, <stephen.smalley.work@gmail.com> + */ + +#ifndef _SS_HASHTAB_H_ +#define _SS_HASHTAB_H_ + +#include <linux/types.h> +#include <linux/errno.h> +#include <linux/sched.h> + +#define HASHTAB_MAX_NODES U32_MAX + +struct hashtab_key_params { + u32 (*hash)(const void *key); /* hash func */ + int (*cmp)(const void *key1, const void *key2); /* comparison func */ +}; + +struct hashtab_node { + void *key; + void *datum; + struct hashtab_node *next; +}; + +struct hashtab { + struct hashtab_node **htable; /* hash table */ + u32 size; /* number of slots in hash table */ + u32 nel; /* number of elements in hash table */ +}; + +struct hashtab_info { + u32 slots_used; + u32 max_chain_len; + u64 chain2_len_sum; +}; + +/* + * Initializes a new hash table with the specified characteristics. + * + * Returns -ENOMEM if insufficient space is available or 0 otherwise. + */ +int hashtab_init(struct hashtab *h, u32 nel_hint); + +int __hashtab_insert(struct hashtab *h, struct hashtab_node **dst, void *key, + void *datum); + +/* + * Inserts the specified (key, datum) pair into the specified hash table. + * + * Returns -ENOMEM on memory allocation error, + * -EEXIST if there is already an entry with the same key, + * -EINVAL for general errors or + 0 otherwise. + */ +static inline int hashtab_insert(struct hashtab *h, void *key, void *datum, + struct hashtab_key_params key_params) +{ + u32 hvalue; + struct hashtab_node *prev, *cur; + + cond_resched(); + + if (!h->size || h->nel == HASHTAB_MAX_NODES) + return -EINVAL; + + hvalue = key_params.hash(key) & (h->size - 1); + prev = NULL; + cur = h->htable[hvalue]; + while (cur) { + int cmp = key_params.cmp(key, cur->key); + + if (cmp == 0) + return -EEXIST; + if (cmp < 0) + break; + prev = cur; + cur = cur->next; + } + + return __hashtab_insert(h, prev ? &prev->next : &h->htable[hvalue], key, + datum); +} + +/* + * Searches for the entry with the specified key in the hash table. + * + * Returns NULL if no entry has the specified key or + * the datum of the entry otherwise. + */ +static inline void *hashtab_search(const struct hashtab *h, const void *key, + struct hashtab_key_params key_params) +{ + u32 hvalue; + const struct hashtab_node *cur; + + if (!h->size) + return NULL; + + hvalue = key_params.hash(key) & (h->size - 1); + cur = h->htable[hvalue]; + while (cur) { + int cmp = key_params.cmp(key, cur->key); + + if (cmp == 0) + return cur->datum; + if (cmp < 0) + break; + cur = cur->next; + } + return NULL; +} + +/* + * Destroys the specified hash table. + */ +void hashtab_destroy(struct hashtab *h); + +/* + * Applies the specified apply function to (key,datum,args) + * for each entry in the specified hash table. + * + * The order in which the function is applied to the entries + * is dependent upon the internal structure of the hash table. + * + * If apply returns a non-zero status, then hashtab_map will cease + * iterating through the hash table and will propagate the error + * return to its caller. + */ +int hashtab_map(struct hashtab *h, int (*apply)(void *k, void *d, void *args), + void *args); + +int hashtab_duplicate(struct hashtab *new, const struct hashtab *orig, + int (*copy)(struct hashtab_node *new, + const struct hashtab_node *orig, void *args), + int (*destroy)(void *k, void *d, void *args), void *args); + +#ifdef CONFIG_SECURITY_SELINUX_DEBUG +/* Fill info with some hash table statistics */ +void hashtab_stat(struct hashtab *h, struct hashtab_info *info); +#else +static inline void hashtab_stat(struct hashtab *h, struct hashtab_info *info) +{ + return; +} +#endif + +#endif /* _SS_HASHTAB_H */ diff --git a/security/selinux/ss/mls.c b/security/selinux/ss/mls.c new file mode 100644 index 000000000..40c626006 --- /dev/null +++ b/security/selinux/ss/mls.c @@ -0,0 +1,653 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Implementation of the multi-level security (MLS) policy. + * + * Author : Stephen Smalley, <stephen.smalley.work@gmail.com> + */ + +/* + * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com> + * Support for enhanced MLS infrastructure. + * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc. + * + * Updated: Hewlett-Packard <paul@paul-moore.com> + * Added support to import/export the MLS label from NetLabel + * Copyright (C) Hewlett-Packard Development Company, L.P., 2006 + */ + +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/string.h> +#include <linux/errno.h> +#include <net/netlabel.h> +#include "sidtab.h" +#include "mls.h" +#include "policydb.h" +#include "services.h" + +/* + * Return the length in bytes for the MLS fields of the + * security context string representation of `context'. + */ +int mls_compute_context_len(struct policydb *p, struct context *context) +{ + int i, l, len, head, prev; + const char *nm; + struct ebitmap *e; + struct ebitmap_node *node; + + if (!p->mls_enabled) + return 0; + + len = 1; /* for the beginning ":" */ + for (l = 0; l < 2; l++) { + u32 index_sens = context->range.level[l].sens; + len += strlen(sym_name(p, SYM_LEVELS, index_sens - 1)); + + /* categories */ + head = -2; + prev = -2; + e = &context->range.level[l].cat; + ebitmap_for_each_positive_bit(e, node, i) + { + if (i - prev > 1) { + /* one or more negative bits are skipped */ + if (head != prev) { + nm = sym_name(p, SYM_CATS, prev); + len += strlen(nm) + 1; + } + nm = sym_name(p, SYM_CATS, i); + len += strlen(nm) + 1; + head = i; + } + prev = i; + } + if (prev != head) { + nm = sym_name(p, SYM_CATS, prev); + len += strlen(nm) + 1; + } + if (l == 0) { + if (mls_level_eq(&context->range.level[0], + &context->range.level[1])) + break; + else + len++; + } + } + + return len; +} + +/* + * Write the security context string representation of + * the MLS fields of `context' into the string `*scontext'. + * Update `*scontext' to point to the end of the MLS fields. + */ +void mls_sid_to_context(struct policydb *p, struct context *context, + char **scontext) +{ + const char *nm; + char *scontextp; + int i, l, head, prev; + struct ebitmap *e; + struct ebitmap_node *node; + + if (!p->mls_enabled) + return; + + scontextp = *scontext; + + *scontextp = ':'; + scontextp++; + + for (l = 0; l < 2; l++) { + strcpy(scontextp, sym_name(p, SYM_LEVELS, + context->range.level[l].sens - 1)); + scontextp += strlen(scontextp); + + /* categories */ + head = -2; + prev = -2; + e = &context->range.level[l].cat; + ebitmap_for_each_positive_bit(e, node, i) + { + if (i - prev > 1) { + /* one or more negative bits are skipped */ + if (prev != head) { + if (prev - head > 1) + *scontextp++ = '.'; + else + *scontextp++ = ','; + nm = sym_name(p, SYM_CATS, prev); + strcpy(scontextp, nm); + scontextp += strlen(nm); + } + if (prev < 0) + *scontextp++ = ':'; + else + *scontextp++ = ','; + nm = sym_name(p, SYM_CATS, i); + strcpy(scontextp, nm); + scontextp += strlen(nm); + head = i; + } + prev = i; + } + + if (prev != head) { + if (prev - head > 1) + *scontextp++ = '.'; + else + *scontextp++ = ','; + nm = sym_name(p, SYM_CATS, prev); + strcpy(scontextp, nm); + scontextp += strlen(nm); + } + + if (l == 0) { + if (mls_level_eq(&context->range.level[0], + &context->range.level[1])) + break; + else + *scontextp++ = '-'; + } + } + + *scontext = scontextp; +} + +bool mls_level_isvalid(const struct policydb *p, const struct mls_level *l) +{ + const char *name; + const struct level_datum *levdatum; + + if (!l->sens || l->sens > p->p_levels.nprim) + return false; + + name = sym_name(p, SYM_LEVELS, l->sens - 1); + if (!name) + return false; + + levdatum = symtab_search(&p->p_levels, name); + if (!levdatum) + return false; + + /* + * l is valid iff every bit in l->cat is set in levdatum->level.cat + * and no bit in l->cat is larger than p->p_cats.nprim. + * policydb_index() has already verified that every bit set in + * levdatum->level.cat names a defined category, so containment is + * sufficient here. + */ + return ebitmap_contains(&levdatum->level.cat, &l->cat, + p->p_cats.nprim); +} + +bool mls_range_isvalid(const struct policydb *p, const struct mls_range *r) +{ + return (mls_level_isvalid(p, &r->level[0]) && + mls_level_isvalid(p, &r->level[1]) && + mls_level_dom(&r->level[1], &r->level[0])); +} + +/* + * Return true if the MLS fields in the security context + * structure `c' are valid. Return 0 otherwise. + */ +bool mls_context_isvalid(const struct policydb *p, const struct context *c) +{ + const struct user_datum *usrdatum; + + if (!p->mls_enabled) + return true; + + if (!mls_range_isvalid(p, &c->range)) + return false; + + if (c->role == OBJECT_R_VAL) + return true; + + /* + * User must be authorized for the MLS range. + */ + if (!c->user || c->user > p->p_users.nprim) + return false; + usrdatum = p->user_val_to_struct[c->user - 1]; + if (!usrdatum || !mls_range_contains(usrdatum->range, c->range)) + return false; /* user may not be associated with range */ + + return true; +} + +/* + * Set the MLS fields in the security context structure + * `context' based on the string representation in + * the string `scontext'. + * + * This function modifies the string in place, inserting + * NULL characters to terminate the MLS fields. + * + * If a def_sid is provided and no MLS field is present, + * copy the MLS field of the associated default context. + * Used for upgraded to MLS systems where objects may lack + * MLS fields. + * + * Policy read-lock must be held for sidtab lookup. + * + */ +int mls_context_to_sid(struct policydb *pol, char oldc, char *scontext, + struct context *context, struct sidtab *s, u32 def_sid) +{ + char *sensitivity, *cur_cat, *next_cat, *rngptr; + struct level_datum *levdatum; + struct cat_datum *catdatum, *rngdatum; + u32 i; + int l, rc; + char *rangep[2]; + + if (!pol->mls_enabled) { + /* + * With no MLS, only return -EINVAL if there is a MLS field + * and it did not come from an xattr. + */ + if (oldc && def_sid == SECSID_NULL) + return -EINVAL; + return 0; + } + + /* + * No MLS component to the security context, try and map to + * default if provided. + */ + if (!oldc) { + struct context *defcon; + + if (def_sid == SECSID_NULL) + return -EINVAL; + + defcon = sidtab_search(s, def_sid); + if (!defcon) + return -EINVAL; + + return mls_context_cpy(context, defcon); + } + + /* + * If we're dealing with a range, figure out where the two parts + * of the range begin. + */ + rangep[0] = scontext; + rangep[1] = strchr(scontext, '-'); + if (rangep[1]) { + rangep[1][0] = '\0'; + rangep[1]++; + } + + /* For each part of the range: */ + for (l = 0; l < 2; l++) { + /* Split sensitivity and category set. */ + sensitivity = rangep[l]; + if (sensitivity == NULL) + break; + next_cat = strchr(sensitivity, ':'); + if (next_cat) + *(next_cat++) = '\0'; + + /* Parse sensitivity. */ + levdatum = symtab_search(&pol->p_levels, sensitivity); + if (!levdatum) + return -EINVAL; + context->range.level[l].sens = levdatum->level.sens; + + /* Extract category set. */ + while (next_cat != NULL) { + cur_cat = next_cat; + next_cat = strchr(next_cat, ','); + if (next_cat != NULL) + *(next_cat++) = '\0'; + + /* Separate into range if exists */ + rngptr = strchr(cur_cat, '.'); + if (rngptr != NULL) { + /* Remove '.' */ + *rngptr++ = '\0'; + } + + catdatum = symtab_search(&pol->p_cats, cur_cat); + if (!catdatum) + return -EINVAL; + + rc = ebitmap_set_bit(&context->range.level[l].cat, + catdatum->value - 1, 1); + if (rc) + return rc; + + /* If range, set all categories in range */ + if (rngptr == NULL) + continue; + + rngdatum = symtab_search(&pol->p_cats, rngptr); + if (!rngdatum) + return -EINVAL; + + if (catdatum->value >= rngdatum->value) + return -EINVAL; + + for (i = catdatum->value; i < rngdatum->value; i++) { + rc = ebitmap_set_bit( + &context->range.level[l].cat, i, 1); + if (rc) + return rc; + } + } + } + + /* If we didn't see a '-', the range start is also the range end. */ + if (rangep[1] == NULL) { + context->range.level[1].sens = context->range.level[0].sens; + rc = ebitmap_cpy(&context->range.level[1].cat, + &context->range.level[0].cat); + if (rc) + return rc; + } + + return 0; +} + +/* + * Set the MLS fields in the security context structure + * `context' based on the string representation in + * the string `str'. This function will allocate temporary memory with the + * given constraints of gfp_mask. + */ +int mls_from_string(struct policydb *p, char *str, struct context *context, + gfp_t gfp_mask) +{ + char *tmpstr; + int rc; + + if (!p->mls_enabled) + return -EINVAL; + + tmpstr = kstrdup(str, gfp_mask); + if (!tmpstr) { + rc = -ENOMEM; + } else { + rc = mls_context_to_sid(p, ':', tmpstr, context, NULL, + SECSID_NULL); + kfree(tmpstr); + } + + return rc; +} + +/* + * Copies the MLS range `range' into `context'. + */ +int mls_range_set(struct context *context, struct mls_range *range) +{ + int l, rc = 0; + + /* Copy the MLS range into the context */ + for (l = 0; l < 2; l++) { + context->range.level[l].sens = range->level[l].sens; + rc = ebitmap_cpy(&context->range.level[l].cat, + &range->level[l].cat); + if (rc) + break; + } + + return rc; +} + +int mls_setup_user_range(struct policydb *p, struct context *fromcon, + struct user_datum *user, struct context *usercon) +{ + if (p->mls_enabled) { + struct mls_level *fromcon_sen = &(fromcon->range.level[0]); + struct mls_level *fromcon_clr = &(fromcon->range.level[1]); + struct mls_level *user_low = &(user->range.level[0]); + struct mls_level *user_clr = &(user->range.level[1]); + struct mls_level *user_def = &(user->dfltlevel); + struct mls_level *usercon_sen = &(usercon->range.level[0]); + struct mls_level *usercon_clr = &(usercon->range.level[1]); + + /* Honor the user's default level if we can */ + if (mls_level_between(user_def, fromcon_sen, fromcon_clr)) + *usercon_sen = *user_def; + else if (mls_level_between(fromcon_sen, user_def, user_clr)) + *usercon_sen = *fromcon_sen; + else if (mls_level_between(fromcon_clr, user_low, user_def)) + *usercon_sen = *user_low; + else + return -EINVAL; + + /* Lower the clearance of available contexts + if the clearance of "fromcon" is lower than + that of the user's default clearance (but + only if the "fromcon" clearance dominates + the user's computed sensitivity level) */ + if (mls_level_dom(user_clr, fromcon_clr)) + *usercon_clr = *fromcon_clr; + else if (mls_level_dom(fromcon_clr, user_clr)) + *usercon_clr = *user_clr; + else + return -EINVAL; + } + + return 0; +} + +/* + * Convert the MLS fields in the security context + * structure `oldc' from the values specified in the + * policy `oldp' to the values specified in the policy `newp', + * storing the resulting context in `newc'. + */ +int mls_convert_context(struct policydb *oldp, struct policydb *newp, + struct context *oldc, struct context *newc) +{ + struct level_datum *levdatum; + struct cat_datum *catdatum; + struct ebitmap_node *node; + u32 i; + int l; + + if (!oldp->mls_enabled || !newp->mls_enabled) + return 0; + + for (l = 0; l < 2; l++) { + const char *name = sym_name(oldp, SYM_LEVELS, + oldc->range.level[l].sens - 1); + + levdatum = symtab_search(&newp->p_levels, name); + + if (!levdatum) + return -EINVAL; + newc->range.level[l].sens = levdatum->level.sens; + + ebitmap_for_each_positive_bit(&oldc->range.level[l].cat, node, + i) + { + int rc; + + catdatum = symtab_search(&newp->p_cats, + sym_name(oldp, SYM_CATS, i)); + if (!catdatum) + return -EINVAL; + rc = ebitmap_set_bit(&newc->range.level[l].cat, + catdatum->value - 1, 1); + if (rc) + return rc; + } + } + + return 0; +} + +int mls_compute_sid(struct policydb *p, struct context *scontext, + struct context *tcontext, u16 tclass, u32 specified, + struct context *newcontext, bool sock) +{ + struct range_trans rtr; + struct mls_range *r; + struct class_datum *cladatum; + char default_range = 0; + + if (!p->mls_enabled) + return 0; + + switch (specified) { + case AVTAB_TRANSITION: + /* Look for a range transition rule. */ + rtr.source_type = scontext->type; + rtr.target_type = tcontext->type; + rtr.target_class = tclass; + r = policydb_rangetr_search(p, &rtr); + if (r) + return mls_range_set(newcontext, r); + + if (tclass && tclass <= p->p_classes.nprim) { + cladatum = p->class_val_to_struct[tclass - 1]; + if (cladatum) + default_range = cladatum->default_range; + } + + switch (default_range) { + case DEFAULT_SOURCE_LOW: + return mls_context_cpy_low(newcontext, scontext); + case DEFAULT_SOURCE_HIGH: + return mls_context_cpy_high(newcontext, scontext); + case DEFAULT_SOURCE_LOW_HIGH: + return mls_context_cpy(newcontext, scontext); + case DEFAULT_TARGET_LOW: + return mls_context_cpy_low(newcontext, tcontext); + case DEFAULT_TARGET_HIGH: + return mls_context_cpy_high(newcontext, tcontext); + case DEFAULT_TARGET_LOW_HIGH: + return mls_context_cpy(newcontext, tcontext); + case DEFAULT_GLBLUB: + return mls_context_glblub(newcontext, scontext, + tcontext); + } + + fallthrough; + case AVTAB_CHANGE: + if ((tclass == p->process_class) || sock) + /* Use the process MLS attributes. */ + return mls_context_cpy(newcontext, scontext); + else + /* Use the process effective MLS attributes. */ + return mls_context_cpy_low(newcontext, scontext); + case AVTAB_MEMBER: + /* Use the process effective MLS attributes. */ + return mls_context_cpy_low(newcontext, scontext); + } + return -EINVAL; +} + +#ifdef CONFIG_NETLABEL +/** + * mls_export_netlbl_lvl - Export the MLS sensitivity levels to NetLabel + * @p: the policy + * @context: the security context + * @secattr: the NetLabel security attributes + * + * Description: + * Given the security context copy the low MLS sensitivity level into the + * NetLabel MLS sensitivity level field. + * + */ +void mls_export_netlbl_lvl(struct policydb *p, struct context *context, + struct netlbl_lsm_secattr *secattr) +{ + if (!p->mls_enabled) + return; + + secattr->attr.mls.lvl = context->range.level[0].sens - 1; + secattr->flags |= NETLBL_SECATTR_MLS_LVL; +} + +/** + * mls_import_netlbl_lvl - Import the NetLabel MLS sensitivity levels + * @p: the policy + * @context: the security context + * @secattr: the NetLabel security attributes + * + * Description: + * Given the security context and the NetLabel security attributes, copy the + * NetLabel MLS sensitivity level into the context. + * + */ +void mls_import_netlbl_lvl(struct policydb *p, struct context *context, + struct netlbl_lsm_secattr *secattr) +{ + if (!p->mls_enabled) + return; + + context->range.level[0].sens = secattr->attr.mls.lvl + 1; + context->range.level[1].sens = context->range.level[0].sens; +} + +/** + * mls_export_netlbl_cat - Export the MLS categories to NetLabel + * @p: the policy + * @context: the security context + * @secattr: the NetLabel security attributes + * + * Description: + * Given the security context copy the low MLS categories into the NetLabel + * MLS category field. Returns zero on success, negative values on failure. + * + */ +int mls_export_netlbl_cat(struct policydb *p, struct context *context, + struct netlbl_lsm_secattr *secattr) +{ + int rc; + + if (!p->mls_enabled) + return 0; + + rc = ebitmap_netlbl_export(&context->range.level[0].cat, + &secattr->attr.mls.cat); + if (rc == 0 && secattr->attr.mls.cat != NULL) + secattr->flags |= NETLBL_SECATTR_MLS_CAT; + + return rc; +} + +/** + * mls_import_netlbl_cat - Import the MLS categories from NetLabel + * @p: the policy + * @context: the security context + * @secattr: the NetLabel security attributes + * + * Description: + * Copy the NetLabel security attributes into the SELinux context; since the + * NetLabel security attribute only contains a single MLS category use it for + * both the low and high categories of the context. Returns zero on success, + * negative values on failure. + * + */ +int mls_import_netlbl_cat(struct policydb *p, struct context *context, + struct netlbl_lsm_secattr *secattr) +{ + int rc; + + if (!p->mls_enabled) + return 0; + + rc = ebitmap_netlbl_import(&context->range.level[0].cat, + secattr->attr.mls.cat); + if (rc) + goto import_netlbl_cat_failure; + memcpy(&context->range.level[1].cat, &context->range.level[0].cat, + sizeof(context->range.level[0].cat)); + + return 0; + +import_netlbl_cat_failure: + ebitmap_destroy(&context->range.level[0].cat); + return rc; +} +#endif /* CONFIG_NETLABEL */ diff --git a/security/selinux/ss/mls.h b/security/selinux/ss/mls.h new file mode 100644 index 000000000..93cde1b22 --- /dev/null +++ b/security/selinux/ss/mls.h @@ -0,0 +1,96 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Multi-level security (MLS) policy operations. + * + * Author : Stephen Smalley, <stephen.smalley.work@gmail.com> + */ + +/* + * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com> + * Support for enhanced MLS infrastructure. + * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc. + * + * Updated: Hewlett-Packard <paul@paul-moore.com> + * Added support to import/export the MLS label from NetLabel + * Copyright (X) Hewlett-Packard Development Company, L.P., 2006 + */ + +#ifndef _SS_MLS_H_ +#define _SS_MLS_H_ + +#include <linux/jhash.h> + +#include "context.h" +#include "ebitmap.h" +#include "policydb.h" + +int mls_compute_context_len(struct policydb *p, struct context *context); +void mls_sid_to_context(struct policydb *p, struct context *context, + char **scontext); +bool mls_context_isvalid(const struct policydb *p, const struct context *c); +bool mls_range_isvalid(const struct policydb *p, const struct mls_range *r); +bool mls_level_isvalid(const struct policydb *p, const struct mls_level *l); + +int mls_context_to_sid(struct policydb *p, char oldc, char *scontext, + struct context *context, struct sidtab *s, u32 def_sid); + +int mls_from_string(struct policydb *p, char *str, struct context *context, + gfp_t gfp_mask); + +int mls_range_set(struct context *context, struct mls_range *range); + +int mls_convert_context(struct policydb *oldp, struct policydb *newp, + struct context *oldc, struct context *newc); + +int mls_compute_sid(struct policydb *p, struct context *scontext, + struct context *tcontext, u16 tclass, u32 specified, + struct context *newcontext, bool sock); + +int mls_setup_user_range(struct policydb *p, struct context *fromcon, + struct user_datum *user, struct context *usercon); + +#ifdef CONFIG_NETLABEL +void mls_export_netlbl_lvl(struct policydb *p, struct context *context, + struct netlbl_lsm_secattr *secattr); +void mls_import_netlbl_lvl(struct policydb *p, struct context *context, + struct netlbl_lsm_secattr *secattr); +int mls_export_netlbl_cat(struct policydb *p, struct context *context, + struct netlbl_lsm_secattr *secattr); +int mls_import_netlbl_cat(struct policydb *p, struct context *context, + struct netlbl_lsm_secattr *secattr); +#else +static inline void mls_export_netlbl_lvl(struct policydb *p, + struct context *context, + struct netlbl_lsm_secattr *secattr) +{ + return; +} +static inline void mls_import_netlbl_lvl(struct policydb *p, + struct context *context, + struct netlbl_lsm_secattr *secattr) +{ + return; +} +static inline int mls_export_netlbl_cat(struct policydb *p, + struct context *context, + struct netlbl_lsm_secattr *secattr) +{ + return -ENOMEM; +} +static inline int mls_import_netlbl_cat(struct policydb *p, + struct context *context, + struct netlbl_lsm_secattr *secattr) +{ + return -ENOMEM; +} +#endif + +static inline u32 mls_range_hash(const struct mls_range *r, u32 hash) +{ + hash = jhash_2words(r->level[0].sens, r->level[1].sens, hash); + hash = ebitmap_hash(&r->level[0].cat, hash); + hash = ebitmap_hash(&r->level[1].cat, hash); + return hash; +} + +#endif /* _SS_MLS_H */ diff --git a/security/selinux/ss/mls_types.h b/security/selinux/ss/mls_types.h new file mode 100644 index 000000000..51df2ebd1 --- /dev/null +++ b/security/selinux/ss/mls_types.h @@ -0,0 +1,52 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Type definitions for the multi-level security (MLS) policy. + * + * Author : Stephen Smalley, <stephen.smalley.work@gmail.com> + */ + +/* + * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com> + * Support for enhanced MLS infrastructure. + * Copyright (C) 2004-2005 Trusted Computer Solutions, Inc. + */ + +#ifndef _SS_MLS_TYPES_H_ +#define _SS_MLS_TYPES_H_ + +#include "security.h" +#include "ebitmap.h" + +struct mls_level { + u32 sens; /* sensitivity */ + struct ebitmap cat; /* category set */ +}; + +struct mls_range { + struct mls_level level[2]; /* low == level[0], high == level[1] */ +}; + +static inline int mls_level_eq(const struct mls_level *l1, + const struct mls_level *l2) +{ + return ((l1->sens == l2->sens) && ebitmap_equal(&l1->cat, &l2->cat)); +} + +static inline int mls_level_dom(const struct mls_level *l1, + const struct mls_level *l2) +{ + return ((l1->sens >= l2->sens) && + ebitmap_contains(&l1->cat, &l2->cat, 0)); +} + +#define mls_level_incomp(l1, l2) \ + (!mls_level_dom((l1), (l2)) && !mls_level_dom((l2), (l1))) + +#define mls_level_between(l1, l2, l3) \ + (mls_level_dom((l1), (l2)) && mls_level_dom((l3), (l1))) + +#define mls_range_contains(r1, r2) \ + (mls_level_dom(&(r2).level[0], &(r1).level[0]) && \ + mls_level_dom(&(r1).level[1], &(r2).level[1])) + +#endif /* _SS_MLS_TYPES_H_ */ diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c new file mode 100644 index 000000000..b75c977c6 --- /dev/null +++ b/security/selinux/ss/policydb.c @@ -0,0 +1,4155 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Implementation of the policy database. + * + * Author : Stephen Smalley, <stephen.smalley.work@gmail.com> + */ + +/* + * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com> + * Support for enhanced MLS infrastructure. + * Copyright (C) 2004-2005 Trusted Computer Solutions, Inc. + * + * Updated: Frank Mayer <mayerf@tresys.com> and + * Karl MacMillan <kmacmillan@tresys.com> + * Added conditional policy language extensions + * Copyright (C) 2003-2004 Tresys Technology, LLC + * + * Updated: Hewlett-Packard <paul@paul-moore.com> + * Added support for the policy capability bitmap + * Copyright (C) 2007 Hewlett-Packard Development Company, L.P. + * + * Update: Mellanox Techonologies + * Added Infiniband support + * Copyright (C) 2016 Mellanox Techonologies + */ + +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/string.h> +#include <linux/errno.h> +#include <linux/audit.h> +#include <linux/sort.h> +#include "security.h" + +#include "policydb.h" +#include "conditional.h" +#include "mls.h" +#include "services.h" + +#ifdef CONFIG_SECURITY_SELINUX_DEBUG +/* clang-format off */ +static const char *const symtab_name[SYM_NUM] = { + "common prefixes", + "classes", + "roles", + "types", + "users", + "bools", + "levels", + "categories", +}; +/* clang-format off */ +#endif + +struct policydb_compat_info { + unsigned int version; + unsigned int sym_num; + unsigned int ocon_num; +}; + +/* These need to be updated if SYM_NUM or OCON_NUM changes */ +static const struct policydb_compat_info policydb_compat[] = { + { + .version = POLICYDB_VERSION_BASE, + .sym_num = SYM_NUM - 3, + .ocon_num = OCON_NUM - 3, + }, + { + .version = POLICYDB_VERSION_BOOL, + .sym_num = SYM_NUM - 2, + .ocon_num = OCON_NUM - 3, + }, + { + .version = POLICYDB_VERSION_IPV6, + .sym_num = SYM_NUM - 2, + .ocon_num = OCON_NUM - 2, + }, + { + .version = POLICYDB_VERSION_NLCLASS, + .sym_num = SYM_NUM - 2, + .ocon_num = OCON_NUM - 2, + }, + { + .version = POLICYDB_VERSION_MLS, + .sym_num = SYM_NUM, + .ocon_num = OCON_NUM - 2, + }, + { + .version = POLICYDB_VERSION_AVTAB, + .sym_num = SYM_NUM, + .ocon_num = OCON_NUM - 2, + }, + { + .version = POLICYDB_VERSION_RANGETRANS, + .sym_num = SYM_NUM, + .ocon_num = OCON_NUM - 2, + }, + { + .version = POLICYDB_VERSION_POLCAP, + .sym_num = SYM_NUM, + .ocon_num = OCON_NUM - 2, + }, + { + .version = POLICYDB_VERSION_PERMISSIVE, + .sym_num = SYM_NUM, + .ocon_num = OCON_NUM - 2, + }, + { + .version = POLICYDB_VERSION_BOUNDARY, + .sym_num = SYM_NUM, + .ocon_num = OCON_NUM - 2, + }, + { + .version = POLICYDB_VERSION_FILENAME_TRANS, + .sym_num = SYM_NUM, + .ocon_num = OCON_NUM - 2, + }, + { + .version = POLICYDB_VERSION_ROLETRANS, + .sym_num = SYM_NUM, + .ocon_num = OCON_NUM - 2, + }, + { + .version = POLICYDB_VERSION_NEW_OBJECT_DEFAULTS, + .sym_num = SYM_NUM, + .ocon_num = OCON_NUM - 2, + }, + { + .version = POLICYDB_VERSION_DEFAULT_TYPE, + .sym_num = SYM_NUM, + .ocon_num = OCON_NUM - 2, + }, + { + .version = POLICYDB_VERSION_CONSTRAINT_NAMES, + .sym_num = SYM_NUM, + .ocon_num = OCON_NUM - 2, + }, + { + .version = POLICYDB_VERSION_XPERMS_IOCTL, + .sym_num = SYM_NUM, + .ocon_num = OCON_NUM - 2, + }, + { + .version = POLICYDB_VERSION_INFINIBAND, + .sym_num = SYM_NUM, + .ocon_num = OCON_NUM, + }, + { + .version = POLICYDB_VERSION_GLBLUB, + .sym_num = SYM_NUM, + .ocon_num = OCON_NUM, + }, + { + .version = POLICYDB_VERSION_COMP_FTRANS, + .sym_num = SYM_NUM, + .ocon_num = OCON_NUM, + }, + { + .version = POLICYDB_VERSION_COND_XPERMS, + .sym_num = SYM_NUM, + .ocon_num = OCON_NUM, + }, + { + .version = POLICYDB_VERSION_NEVERAUDIT, + .sym_num = SYM_NUM, + .ocon_num = OCON_NUM, + }, +}; + +static const struct policydb_compat_info * +policydb_lookup_compat(unsigned int version) +{ + unsigned int i; + + for (i = 0; i < ARRAY_SIZE(policydb_compat); i++) { + if (policydb_compat[i].version == version) + return &policydb_compat[i]; + } + + return NULL; +} + +/* + * The following *_destroy functions are used to + * free any memory allocated for each kind of + * symbol data in the policy database. + */ + +static int perm_destroy(void *key, void *datum, void *p) +{ + kfree(key); + kfree(datum); + return 0; +} + +static int common_destroy(void *key, void *datum, void *p) +{ + struct common_datum *comdatum; + + kfree(key); + if (datum) { + comdatum = datum; + hashtab_map(&comdatum->permissions.table, perm_destroy, NULL); + hashtab_destroy(&comdatum->permissions.table); + } + kfree(datum); + return 0; +} + +static void constraint_expr_destroy(struct constraint_expr *expr) +{ + if (expr) { + ebitmap_destroy(&expr->names); + if (expr->type_names) { + ebitmap_destroy(&expr->type_names->types); + ebitmap_destroy(&expr->type_names->negset); + kfree(expr->type_names); + } + kfree(expr); + } +} + +static int cls_destroy(void *key, void *datum, void *p) +{ + struct class_datum *cladatum; + struct constraint_node *constraint, *ctemp; + struct constraint_expr *e, *etmp; + + kfree(key); + if (datum) { + cladatum = datum; + hashtab_map(&cladatum->permissions.table, perm_destroy, NULL); + hashtab_destroy(&cladatum->permissions.table); + constraint = cladatum->constraints; + while (constraint) { + e = constraint->expr; + while (e) { + etmp = e; + e = e->next; + constraint_expr_destroy(etmp); + } + ctemp = constraint; + constraint = constraint->next; + kfree(ctemp); + } + + constraint = cladatum->validatetrans; + while (constraint) { + e = constraint->expr; + while (e) { + etmp = e; + e = e->next; + constraint_expr_destroy(etmp); + } + ctemp = constraint; + constraint = constraint->next; + kfree(ctemp); + } + kfree(cladatum->comkey); + } + kfree(datum); + return 0; +} + +static int role_destroy(void *key, void *datum, void *p) +{ + struct role_datum *role; + + kfree(key); + if (datum) { + role = datum; + ebitmap_destroy(&role->dominates); + ebitmap_destroy(&role->types); + } + kfree(datum); + return 0; +} + +static int type_destroy(void *key, void *datum, void *p) +{ + kfree(key); + kfree(datum); + return 0; +} + +static int user_destroy(void *key, void *datum, void *p) +{ + struct user_datum *usrdatum; + + kfree(key); + if (datum) { + usrdatum = datum; + ebitmap_destroy(&usrdatum->roles); + ebitmap_destroy(&usrdatum->range.level[0].cat); + ebitmap_destroy(&usrdatum->range.level[1].cat); + ebitmap_destroy(&usrdatum->dfltlevel.cat); + } + kfree(datum); + return 0; +} + +static int sens_destroy(void *key, void *datum, void *p) +{ + struct level_datum *levdatum; + + kfree(key); + if (datum) { + levdatum = datum; + ebitmap_destroy(&levdatum->level.cat); + } + kfree(datum); + return 0; +} + +static int cat_destroy(void *key, void *datum, void *p) +{ + kfree(key); + kfree(datum); + return 0; +} + +/* clang-format off */ +static int (*const destroy_f[SYM_NUM])(void *key, void *datum, void *datap) = { + common_destroy, + cls_destroy, + role_destroy, + type_destroy, + user_destroy, + cond_destroy_bool, + sens_destroy, + cat_destroy, +}; +/* clang-format on */ + +static int filenametr_destroy(void *key, void *datum, void *p) +{ + struct filename_trans_key *ft = key; + struct filename_trans_datum *next, *d = datum; + + kfree(ft->name); + kfree(key); + do { + ebitmap_destroy(&d->stypes); + next = d->next; + kfree(d); + d = next; + } while (unlikely(d)); + cond_resched(); + return 0; +} + +static int range_tr_destroy(void *key, void *datum, void *p) +{ + struct mls_range *rt = datum; + + kfree(key); + ebitmap_destroy(&rt->level[0].cat); + ebitmap_destroy(&rt->level[1].cat); + kfree(datum); + cond_resched(); + return 0; +} + +static int role_tr_destroy(void *key, void *datum, void *p) +{ + kfree(key); + kfree(datum); + return 0; +} + +static void ocontext_destroy(struct ocontext *c, unsigned int i) +{ + if (!c) + return; + + context_destroy(&c->context[0]); + context_destroy(&c->context[1]); + if (i == OCON_ISID || i == OCON_FS || i == OCON_NETIF || + i == OCON_FSUSE) + kfree(c->u.name); + kfree(c); +} + +/* + * Initialize the role table. + */ +static int roles_init(struct policydb *p) +{ + char *key = NULL; + int rc; + struct role_datum *role; + + role = kzalloc_obj(*role); + if (!role) + return -ENOMEM; + + rc = -EINVAL; + role->value = ++p->p_roles.nprim; + if (role->value != OBJECT_R_VAL) + goto out; + + rc = -ENOMEM; + key = kstrdup(OBJECT_R, GFP_KERNEL); + if (!key) + goto out; + + rc = symtab_insert(&p->p_roles, key, role); + if (rc) + goto out; + + return 0; +out: + kfree(key); + kfree(role); + return rc; +} + +static u32 filenametr_hash(const void *k) +{ + const struct filename_trans_key *ft = k; + unsigned long salt = ft->ttype ^ ft->tclass; + + return full_name_hash((void *)salt, ft->name, strlen(ft->name)); +} + +static int filenametr_cmp(const void *k1, const void *k2) +{ + const struct filename_trans_key *ft1 = k1; + const struct filename_trans_key *ft2 = k2; + int v; + + v = cmp_int(ft1->ttype, ft2->ttype); + if (v) + return v; + + v = cmp_int(ft1->tclass, ft2->tclass); + if (v) + return v; + + return strcmp(ft1->name, ft2->name); +} + +static const struct hashtab_key_params filenametr_key_params = { + .hash = filenametr_hash, + .cmp = filenametr_cmp, +}; + +struct filename_trans_datum * +policydb_filenametr_search(struct policydb *p, struct filename_trans_key *key) +{ + return hashtab_search(&p->filename_trans, key, filenametr_key_params); +} + +static u32 rangetr_hash(const void *k) +{ + const struct range_trans *key = k; + + return key->source_type + (key->target_type << 3) + + (key->target_class << 5); +} + +static int rangetr_cmp(const void *k1, const void *k2) +{ + const struct range_trans *key1 = k1, *key2 = k2; + int v; + + v = cmp_int(key1->source_type, key2->source_type); + if (v) + return v; + + v = cmp_int(key1->target_type, key2->target_type); + if (v) + return v; + + v = cmp_int(key1->target_class, key2->target_class); + + return v; +} + +static const struct hashtab_key_params rangetr_key_params = { + .hash = rangetr_hash, + .cmp = rangetr_cmp, +}; + +struct mls_range *policydb_rangetr_search(struct policydb *p, + struct range_trans *key) +{ + return hashtab_search(&p->range_tr, key, rangetr_key_params); +} + +static u32 role_trans_hash(const void *k) +{ + const struct role_trans_key *key = k; + + return jhash_3words(key->role, key->type, + (u32)key->tclass << 16 | key->tclass, 0); +} + +static int role_trans_cmp(const void *k1, const void *k2) +{ + const struct role_trans_key *key1 = k1, *key2 = k2; + int v; + + v = cmp_int(key1->role, key2->role); + if (v) + return v; + + v = cmp_int(key1->type, key2->type); + if (v) + return v; + + return cmp_int(key1->tclass, key2->tclass); +} + +static const struct hashtab_key_params roletr_key_params = { + .hash = role_trans_hash, + .cmp = role_trans_cmp, +}; + +struct role_trans_datum *policydb_roletr_search(struct policydb *p, + struct role_trans_key *key) +{ + return hashtab_search(&p->role_tr, key, roletr_key_params); +} + +/* + * Initialize a policy database structure. + */ +static void policydb_init(struct policydb *p) +{ + memset(p, 0, sizeof(*p)); + + avtab_init(&p->te_avtab); + cond_policydb_init(p); + + ebitmap_init(&p->filename_trans_ttypes); + ebitmap_init(&p->policycaps); + ebitmap_init(&p->permissive_map); + ebitmap_init(&p->neveraudit_map); +} + +/* + * The following *_index functions are used to + * define the val_to_name and val_to_struct arrays + * in a policy database structure. The val_to_name + * arrays are used when converting security context + * structures into string representations. The + * val_to_struct arrays are used when the attributes + * of a class, role, or user are needed. + */ + +static int common_index(void *key, void *datum, void *datap) +{ + struct policydb *p; + struct common_datum *comdatum; + + comdatum = datum; + p = datap; + if (!comdatum->value || comdatum->value > p->p_commons.nprim) + return -EINVAL; + + p->sym_val_to_name[SYM_COMMONS][comdatum->value - 1] = key; + + return 0; +} + +static int class_index(void *key, void *datum, void *datap) +{ + struct policydb *p; + struct class_datum *cladatum; + + cladatum = datum; + p = datap; + if (!cladatum->value || cladatum->value > p->p_classes.nprim) + return -EINVAL; + + p->sym_val_to_name[SYM_CLASSES][cladatum->value - 1] = key; + p->class_val_to_struct[cladatum->value - 1] = cladatum; + return 0; +} + +static int role_index(void *key, void *datum, void *datap) +{ + struct policydb *p; + struct role_datum *role; + + role = datum; + p = datap; + if (!role->value || role->value > p->p_roles.nprim || + role->bounds > p->p_roles.nprim) + return -EINVAL; + + p->sym_val_to_name[SYM_ROLES][role->value - 1] = key; + p->role_val_to_struct[role->value - 1] = role; + return 0; +} + +static int type_index(void *key, void *datum, void *datap) +{ + struct policydb *p; + struct type_datum *typdatum; + + typdatum = datum; + p = datap; + + if (!typdatum->value || typdatum->value > p->p_types.nprim || + typdatum->bounds > p->p_types.nprim) { + pr_err("SELinux: type %s had value %u bounds %u nprim %u\n", + (char *)key, typdatum->value, typdatum->bounds, + p->p_types.nprim); + return -EINVAL; + } + + if (typdatum->primary) { + p->sym_val_to_name[SYM_TYPES][typdatum->value - 1] = key; + p->type_val_to_struct[typdatum->value - 1] = typdatum; + } + + return 0; +} + +static int user_index(void *key, void *datum, void *datap) +{ + struct policydb *p; + struct user_datum *usrdatum; + + usrdatum = datum; + p = datap; + if (!usrdatum->value || usrdatum->value > p->p_users.nprim || + usrdatum->bounds > p->p_users.nprim) + return -EINVAL; + + p->sym_val_to_name[SYM_USERS][usrdatum->value - 1] = key; + p->user_val_to_struct[usrdatum->value - 1] = usrdatum; + return 0; +} + +static int sens_index(void *key, void *datum, void *datap) +{ + struct policydb *p; + struct level_datum *levdatum; + + levdatum = datum; + p = datap; + + if (!levdatum->level.sens || levdatum->level.sens > p->p_levels.nprim) + return -EINVAL; + + if (!levdatum->isalias) + p->sym_val_to_name[SYM_LEVELS][levdatum->level.sens - 1] = key; + + return 0; +} + +static int cat_index(void *key, void *datum, void *datap) +{ + struct policydb *p; + struct cat_datum *catdatum; + + catdatum = datum; + p = datap; + + if (!catdatum->value || catdatum->value > p->p_cats.nprim) + return -EINVAL; + + if (!catdatum->isalias) + p->sym_val_to_name[SYM_CATS][catdatum->value - 1] = key; + + return 0; +} + +static int sens_cat_index_check(void *key, void *datum, void *datap) +{ + struct policydb *p = datap; + struct level_datum *levdatum = datum; + struct ebitmap_node *node; + u32 bit; + + ebitmap_for_each_positive_bit(&levdatum->level.cat, node, bit) { + if (bit >= p->p_cats.nprim || !sym_name(p, SYM_CATS, bit)) { + pr_err("SELinux: sensitivity %s allows undefined category %u\n", + (const char *)key, bit + 1); + return -EINVAL; + } + } + return 0; +} + +/* clang-format off */ +static int (*const index_f[SYM_NUM])(void *key, void *datum, void *datap) = { + common_index, + class_index, + role_index, + type_index, + user_index, + cond_index_bool, + sens_index, + cat_index, +}; +/* clang-format on */ + +#ifdef CONFIG_SECURITY_SELINUX_DEBUG +static void hash_eval(struct hashtab *h, const char *hash_name, + const char *hash_details) +{ + struct hashtab_info info; + + hashtab_stat(h, &info); + pr_debug( + "SELinux: %s%s%s: %d entries and %d/%d buckets used, longest chain length %d, sum of chain length^2 %llu\n", + hash_name, hash_details ? "@" : "", hash_details ?: "", h->nel, + info.slots_used, h->size, info.max_chain_len, + info.chain2_len_sum); +} + +static void symtab_hash_eval(struct symtab *s) +{ + int i; + + for (i = 0; i < SYM_NUM; i++) + hash_eval(&s[i].table, symtab_name[i], NULL); +} + +#else +static inline void hash_eval(struct hashtab *h, const char *hash_name, + const char *hash_details) +{ +} +static inline void symtab_hash_eval(struct symtab *s) +{ +} +#endif /* CONFIG_SECURITY_SELINUX_DEBUG */ + +/* + * Define the other val_to_name and val_to_struct arrays + * in a policy database structure. + * + * Caller must clean up on failure. + */ +static int policydb_index(struct policydb *p) +{ + int i, rc; + u32 v; + + if (p->mls_enabled) + pr_debug( + "SELinux: %d users, %d roles, %d types, %d bools, %d sens, %d cats\n", + p->p_users.nprim, p->p_roles.nprim, p->p_types.nprim, + p->p_bools.nprim, p->p_levels.nprim, p->p_cats.nprim); + else + pr_debug("SELinux: %d users, %d roles, %d types, %d bools\n", + p->p_users.nprim, p->p_roles.nprim, p->p_types.nprim, + p->p_bools.nprim); + + pr_debug("SELinux: %d classes, %d rules\n", p->p_classes.nprim, + p->te_avtab.nel); + + symtab_hash_eval(p->symtab); + + p->class_val_to_struct = kzalloc_objs(*p->class_val_to_struct, + p->p_classes.nprim); + if (!p->class_val_to_struct) + return -ENOMEM; + + p->role_val_to_struct = kzalloc_objs(*p->role_val_to_struct, + p->p_roles.nprim); + if (!p->role_val_to_struct) + return -ENOMEM; + + p->user_val_to_struct = kzalloc_objs(*p->user_val_to_struct, + p->p_users.nprim); + if (!p->user_val_to_struct) + return -ENOMEM; + + p->type_val_to_struct = kvzalloc_objs(*p->type_val_to_struct, + p->p_types.nprim); + if (!p->type_val_to_struct) + return -ENOMEM; + + rc = cond_init_bool_indexes(p); + if (rc) + goto out; + + for (i = 0; i < SYM_NUM; i++) { + p->sym_val_to_name[i] = kvcalloc(p->symtab[i].nprim, + sizeof(char *), GFP_KERNEL); + if (!p->sym_val_to_name[i]) + return -ENOMEM; + + rc = hashtab_map(&p->symtab[i].table, index_f[i], p); + if (rc) + goto out; + } + + /* + * A sparse class value is absorbed by policydb_class_isvalid() and + * its siblings, but no such predicate exists for booleans: every + * user of bool_val_to_struct[] walks it by index and dereferences + * each entry -- cond_evaluate_expr(), the two getters and + * security_set_bools() -- so an unclaimed one has no consumer that + * can tolerate it. + */ + for (v = 0; v < p->p_bools.nprim; v++) { + if (!p->bool_val_to_struct[v]) { + pr_err("SELinux: boolean %u is declared but not defined\n", + v + 1); + rc = -EINVAL; + goto out; + } + } + + if (p->mls_enabled) { + rc = hashtab_map(&p->p_levels.table, sens_cat_index_check, p); + if (rc) + goto out; + } + + rc = 0; +out: + return rc; +} + +/* + * Free any memory allocated by a policy database structure. + */ +void policydb_destroy(struct policydb *p) +{ + struct ocontext *c, *ctmp; + struct genfs *g, *gtmp; + u32 i; + struct role_allow *ra, *lra = NULL; + + for (i = 0; i < SYM_NUM; i++) { + cond_resched(); + hashtab_map(&p->symtab[i].table, destroy_f[i], NULL); + hashtab_destroy(&p->symtab[i].table); + } + + for (i = 0; i < SYM_NUM; i++) + kvfree(p->sym_val_to_name[i]); + + kfree(p->class_val_to_struct); + kfree(p->role_val_to_struct); + kfree(p->user_val_to_struct); + kvfree(p->type_val_to_struct); + + avtab_destroy(&p->te_avtab); + + for (i = 0; i < OCON_NUM; i++) { + cond_resched(); + c = p->ocontexts[i]; + while (c) { + ctmp = c; + c = c->next; + ocontext_destroy(ctmp, i); + } + p->ocontexts[i] = NULL; + } + + g = p->genfs; + while (g) { + cond_resched(); + kfree(g->fstype); + c = g->head; + while (c) { + ctmp = c; + c = c->next; + ocontext_destroy(ctmp, OCON_FSUSE); + } + gtmp = g; + g = g->next; + kfree(gtmp); + } + p->genfs = NULL; + + cond_policydb_destroy(p); + + hashtab_map(&p->role_tr, role_tr_destroy, NULL); + hashtab_destroy(&p->role_tr); + + for (ra = p->role_allow; ra; ra = ra->next) { + cond_resched(); + kfree(lra); + lra = ra; + } + kfree(lra); + + hashtab_map(&p->filename_trans, filenametr_destroy, NULL); + hashtab_destroy(&p->filename_trans); + + hashtab_map(&p->range_tr, range_tr_destroy, NULL); + hashtab_destroy(&p->range_tr); + + if (p->type_attr_map_array) { + for (i = 0; i < p->p_types.nprim; i++) + ebitmap_destroy(&p->type_attr_map_array[i]); + kvfree(p->type_attr_map_array); + } + + ebitmap_destroy(&p->filename_trans_ttypes); + ebitmap_destroy(&p->policycaps); + ebitmap_destroy(&p->permissive_map); + ebitmap_destroy(&p->neveraudit_map); +} + +/* + * Load the initial SIDs specified in a policy database + * structure into a SID table. + */ +int policydb_load_isids(struct policydb *p, struct sidtab *s) +{ + struct ocontext *head, *c; + bool isid_init; + int rc; + + rc = sidtab_init(s); + if (rc) { + pr_err("SELinux: out of memory on SID table init\n"); + return rc; + } + + isid_init = ebitmap_get_bit(&p->policycaps, + POLICYDB_CAP_USERSPACE_INITIAL_CONTEXT); + + head = p->ocontexts[OCON_ISID]; + for (c = head; c; c = c->next) { + u32 sid = c->sid[0]; + const char *name = security_get_initial_sid_context(sid); + + if (sid == SECSID_NULL) { + pr_err("SELinux: SID 0 was assigned a context.\n"); + sidtab_destroy(s); + return -EINVAL; + } + + /* Ignore initial SIDs unused by this kernel. */ + if (!name) + continue; + + /* + * Also ignore SECINITSID_INIT if the policy doesn't declare + * support for it + */ + if (sid == SECINITSID_INIT && !isid_init) + continue; + + rc = sidtab_set_initial(s, sid, &c->context[0]); + if (rc) { + pr_err("SELinux: unable to load initial SID %s.\n", + name); + sidtab_destroy(s); + return rc; + } + + /* + * If the policy doesn't support the "userspace_initial_context" + * capability, set SECINITSID_INIT to the same context as + * SECINITSID_KERNEL. This ensures the same behavior as before + * the reintroduction of SECINITSID_INIT, where all tasks + * started before policy load would initially get the context + * corresponding to SECINITSID_KERNEL. + */ + if (sid == SECINITSID_KERNEL && !isid_init) { + rc = sidtab_set_initial(s, SECINITSID_INIT, + &c->context[0]); + if (rc) { + pr_err("SELinux: unable to load initial SID %s.\n", + name); + sidtab_destroy(s); + return rc; + } + } + } + return 0; +} + +bool policydb_class_isvalid(const struct policydb *p, u16 class) +{ + if (!class || class > p->p_classes.nprim) + return false; + if (!p->sym_val_to_name[SYM_CLASSES][class - 1]) + return false; + return true; +} + +bool policydb_user_isvalid(const struct policydb *p, u32 user) +{ + if (!user || user > p->p_users.nprim) + return false; + if (!p->sym_val_to_name[SYM_USERS][user - 1]) + return false; + return true; +} + +bool policydb_role_isvalid(const struct policydb *p, u32 role) +{ + if (!role || role > p->p_roles.nprim) + return false; + if (!p->sym_val_to_name[SYM_ROLES][role - 1]) + return false; + return true; +} + +bool policydb_type_isvalid(const struct policydb *p, u32 type) +{ + if (!type || type > p->p_types.nprim) + return false; + if (!p->sym_val_to_name[SYM_TYPES][type - 1]) + return false; + return true; +} + +bool policydb_simpletype_isvalid(const struct policydb *p, u32 type) +{ + const struct type_datum *datum; + + if (!type || type > p->p_types.nprim) + return false; + + datum = p->type_val_to_struct[type - 1]; + if (!datum) + return false; + + if (datum->attribute) + return false; + + return true; +} + +/* + * Return true if the fields in the security context + * structure `c' are valid. Return 0 otherwise. + */ +bool policydb_context_isvalid(const struct policydb *p, const struct context *c) +{ + const struct role_datum *role; + const struct user_datum *usrdatum; + + if (!c->role || c->role > p->p_roles.nprim) + return false; + + if (!c->user || c->user > p->p_users.nprim) + return false; + + if (!c->type || c->type > p->p_types.nprim) + return false; + + if (c->role != OBJECT_R_VAL) { + /* + * Role must be authorized for the type. + */ + role = p->role_val_to_struct[c->role - 1]; + if (!role || !ebitmap_get_bit(&role->types, c->type - 1)) + /* role may not be associated with type */ + return false; + + /* + * User must be authorized for the role. + */ + usrdatum = p->user_val_to_struct[c->user - 1]; + if (!usrdatum) + return false; + + if (!ebitmap_get_bit(&usrdatum->roles, c->role - 1)) + /* user may not be associated with role */ + return false; + } + + if (!mls_context_isvalid(p, c)) + return false; + + return true; +} + +/* + * Read a MLS range structure from a policydb binary + * representation file. + */ +static int mls_read_range_helper(struct mls_range *r, struct policy_file *fp) +{ + __le32 buf[2]; + u32 items; + int rc; + + rc = next_entry(buf, fp, sizeof(u32)); + if (rc) + goto out; + + rc = -EINVAL; + items = le32_to_cpu(buf[0]); + if (items > ARRAY_SIZE(buf)) { + pr_err("SELinux: mls: range overflow\n"); + goto out; + } + + rc = next_entry(buf, fp, sizeof(u32) * items); + if (rc) { + pr_err("SELinux: mls: truncated range\n"); + goto out; + } + + r->level[0].sens = le32_to_cpu(buf[0]); + if (items > 1) + r->level[1].sens = le32_to_cpu(buf[1]); + else + r->level[1].sens = r->level[0].sens; + + rc = ebitmap_read(&r->level[0].cat, fp); + if (rc) { + pr_err("SELinux: mls: error reading low categories\n"); + goto out; + } + if (items > 1) { + rc = ebitmap_read(&r->level[1].cat, fp); + if (rc) { + pr_err("SELinux: mls: error reading high categories\n"); + goto bad_high; + } + } else { + rc = ebitmap_cpy(&r->level[1].cat, &r->level[0].cat); + if (rc) { + pr_err("SELinux: mls: out of memory\n"); + goto bad_high; + } + } + + return 0; +bad_high: + ebitmap_destroy(&r->level[0].cat); +out: + return rc; +} + +/* + * Read and validate a security context structure + * from a policydb binary representation file. + */ +static int context_read_and_validate(struct context *c, struct policydb *p, + struct policy_file *fp) +{ + __le32 buf[3]; + int rc; + + rc = next_entry(buf, fp, sizeof buf); + if (rc) { + pr_err("SELinux: context truncated\n"); + goto out; + } + c->user = le32_to_cpu(buf[0]); + c->role = le32_to_cpu(buf[1]); + c->type = le32_to_cpu(buf[2]); + if (p->policyvers >= POLICYDB_VERSION_MLS) { + rc = mls_read_range_helper(&c->range, fp); + if (rc) { + pr_err("SELinux: error reading MLS range of context\n"); + goto out; + } + } + + rc = -EINVAL; + if (!policydb_context_isvalid(p, c)) { + pr_err("SELinux: invalid security context\n"); + context_destroy(c); + goto out; + } + rc = 0; +out: + return rc; +} + +/* + * The following *_read functions are used to + * read the symbol data from a policy database + * binary representation file. + */ + +int str_read(char **strp, gfp_t flags, struct policy_file *fp, u32 len) +{ + int rc; + char *str; + + if ((len == 0) || (len == (u32)-1)) + return -EINVAL; + + if (size_check(sizeof(char), len, fp)) + return -EINVAL; + + str = kmalloc(len + 1, flags | __GFP_NOWARN); + if (!str) + return -ENOMEM; + + rc = next_entry(str, fp, len); + if (rc) { + kfree(str); + return rc; + } + + str[len] = '\0'; + *strp = str; + return 0; +} + +/* + * Bitmap of the permission values a symtab has claimed. Values are 1-based + * and bounded by SEL_VEC_MAX, the width of an access vector, so the whole set + * fits in a u32 and the callers reject an nprim past that width. + */ +static u32 perm_claimed_mask(u32 nprim) +{ + return nprim ? U32_MAX >> (SEL_VEC_MAX - nprim) : 0; +} + +static int perm_read(struct policydb *p, struct symtab *s, + struct policy_file *fp, u32 *claimed) +{ + char *key = NULL; + struct perm_datum *perdatum; + int rc; + __le32 buf[2]; + u32 len; + + perdatum = kzalloc_obj(*perdatum); + if (!perdatum) + return -ENOMEM; + + rc = next_entry(buf, fp, sizeof buf); + if (rc) + goto bad; + + len = le32_to_cpu(buf[0]); + perdatum->value = le32_to_cpu(buf[1]); + rc = -EINVAL; + if (perdatum->value < 1 || perdatum->value > SEL_VEC_MAX) + goto bad; + /* indexes an nprim-sized array in security_get_permissions() */ + if (perdatum->value > s->nprim) + goto bad; + /* two permissions cannot share one slot of that array */ + if (*claimed & (1U << (perdatum->value - 1))) + goto bad; + *claimed |= 1U << (perdatum->value - 1); + + rc = str_read(&key, GFP_KERNEL, fp, len); + if (rc) + goto bad; + + rc = symtab_insert(s, key, perdatum); + if (rc) + goto bad; + + return 0; +bad: + perm_destroy(key, perdatum, NULL); + return rc; +} + +static int common_read(struct policydb *p, struct symtab *s, struct policy_file *fp) +{ + char *key = NULL; + struct common_datum *comdatum; + __le32 buf[4]; + u32 i, len, nel, claimed = 0; + int rc; + + comdatum = kzalloc_obj(*comdatum); + if (!comdatum) + return -ENOMEM; + + rc = next_entry(buf, fp, sizeof buf); + if (rc) + goto bad; + + len = le32_to_cpu(buf[0]); + comdatum->value = le32_to_cpu(buf[1]); + nel = le32_to_cpu(buf[3]); + rc = -EINVAL; + if (nel > SEL_VEC_MAX) + goto bad; + + /* perm_read() reads at least 64 bytes for any valid permission */ + rc = size_check(2 * sizeof(u32), nel, fp); + if (rc) + goto bad; + + rc = symtab_init(&comdatum->permissions, nel); + if (rc) + goto bad; + comdatum->permissions.nprim = le32_to_cpu(buf[2]); + /* no permission value can reach a slot past SEL_VEC_MAX */ + rc = -EINVAL; + if (comdatum->permissions.nprim > SEL_VEC_MAX) + goto bad; + + rc = str_read(&key, GFP_KERNEL, fp, len); + if (rc) + goto bad; + + for (i = 0; i < nel; i++) { + rc = perm_read(p, &comdatum->permissions, fp, &claimed); + if (rc) + goto bad; + } + + rc = -EINVAL; + if (claimed != perm_claimed_mask(comdatum->permissions.nprim)) { + pr_err("SELinux: common %s does not define every permission it declares\n", + key); + goto bad; + } + + hash_eval(&comdatum->permissions.table, "common_permissions", key); + + rc = symtab_insert(s, key, comdatum); + if (rc) + goto bad; + return 0; +bad: + common_destroy(key, comdatum, NULL); + return rc; +} + +static void type_set_init(struct type_set *t) +{ + ebitmap_init(&t->types); + ebitmap_init(&t->negset); +} + +static int type_set_read(struct type_set *t, struct policy_file *fp) +{ + __le32 buf[1]; + int rc; + + if (ebitmap_read(&t->types, fp)) + return -EINVAL; + if (ebitmap_read(&t->negset, fp)) + return -EINVAL; + + rc = next_entry(buf, fp, sizeof(u32)); + if (rc < 0) + return -EINVAL; + t->flags = le32_to_cpu(buf[0]); + + return 0; +} + +static int read_cons_helper(struct policydb *p, struct constraint_node **nodep, + u32 ncons, int allowxtarget, struct policy_file *fp) +{ + struct constraint_node *c, *lc; + struct constraint_expr *e, *le; + __le32 buf[3]; + u32 i, j, nexpr; + int rc, depth; + + lc = NULL; + for (i = 0; i < ncons; i++) { + c = kzalloc_obj(*c); + if (!c) + return -ENOMEM; + + if (lc) + lc->next = c; + else + *nodep = c; + + rc = next_entry(buf, fp, (sizeof(u32) * 2)); + if (rc) + return rc; + c->permissions = le32_to_cpu(buf[0]); + nexpr = le32_to_cpu(buf[1]); + le = NULL; + depth = -1; + for (j = 0; j < nexpr; j++) { + e = kzalloc_obj(*e); + if (!e) + return -ENOMEM; + + if (le) + le->next = e; + else + c->expr = e; + + rc = next_entry(buf, fp, (sizeof(u32) * 3)); + if (rc) + return rc; + e->expr_type = le32_to_cpu(buf[0]); + e->attr = le32_to_cpu(buf[1]); + e->op = le32_to_cpu(buf[2]); + + switch (e->expr_type) { + case CEXPR_NOT: + if (depth < 0) + return -EINVAL; + break; + case CEXPR_AND: + case CEXPR_OR: + if (depth < 1) + return -EINVAL; + depth--; + break; + case CEXPR_ATTR: + if (depth == (CEXPR_MAXDEPTH - 1)) + return -EINVAL; + depth++; + switch (e->attr) { + case CEXPR_USER: + case CEXPR_TYPE: + if (e->op != CEXPR_EQ && + e->op != CEXPR_NEQ) + return -EINVAL; + break; + case CEXPR_ROLE: + case CEXPR_L1L2: + case CEXPR_L1H2: + case CEXPR_H1L2: + case CEXPR_H1H2: + case CEXPR_L1H1: + case CEXPR_L2H2: + if (e->op < CEXPR_EQ || + e->op > CEXPR_INCOMP) + return -EINVAL; + break; + default: + return -EINVAL; + } + break; + case CEXPR_NAMES: + if (!allowxtarget && (e->attr & CEXPR_XTARGET)) + return -EINVAL; + if (depth == (CEXPR_MAXDEPTH - 1)) + return -EINVAL; + depth++; + switch (e->attr & + ~(CEXPR_TARGET|CEXPR_XTARGET)) { + case CEXPR_USER: + case CEXPR_ROLE: + case CEXPR_TYPE: + break; + default: + return -EINVAL; + } + if ((e->attr & (CEXPR_TARGET|CEXPR_XTARGET)) == + (CEXPR_TARGET|CEXPR_XTARGET)) + return -EINVAL; + if (e->op != CEXPR_EQ && e->op != CEXPR_NEQ) + return -EINVAL; + rc = ebitmap_read(&e->names, fp); + if (rc) + return rc; + if (p->policyvers >= + POLICYDB_VERSION_CONSTRAINT_NAMES) { + e->type_names = kzalloc_obj(*e->type_names); + if (!e->type_names) + return -ENOMEM; + type_set_init(e->type_names); + rc = type_set_read(e->type_names, fp); + if (rc) + return rc; + } + break; + default: + return -EINVAL; + } + le = e; + } + if (depth != 0) + return -EINVAL; + lc = c; + } + + return 0; +} + +static int class_read(struct policydb *p, struct symtab *s, struct policy_file *fp) +{ + char *key = NULL; + struct class_datum *cladatum; + __le32 buf[6]; + u32 i, len, len2, ncons, nel, val, claimed = 0, inherited = 0; + int rc; + + cladatum = kzalloc_obj(*cladatum); + if (!cladatum) + return -ENOMEM; + + rc = next_entry(buf, fp, sizeof(u32) * 6); + if (rc) + goto bad; + + len = le32_to_cpu(buf[0]); + len2 = le32_to_cpu(buf[1]); + nel = le32_to_cpu(buf[4]); + rc = -EINVAL; + if (nel > SEL_VEC_MAX) + goto bad; + + val = le32_to_cpu(buf[2]); + rc = -EINVAL; + if (val > U16_MAX) + goto bad; + cladatum->value = val; + + /* perm_read() reads at least 64 bytes for any valid permission */ + rc = size_check(2 * sizeof(u32), nel, fp); + if (rc) + goto bad; + + rc = symtab_init(&cladatum->permissions, nel); + if (rc) + goto bad; + cladatum->permissions.nprim = le32_to_cpu(buf[3]); + /* no permission value can reach a slot past SEL_VEC_MAX */ + rc = -EINVAL; + if (cladatum->permissions.nprim > SEL_VEC_MAX) + goto bad; + + ncons = le32_to_cpu(buf[5]); + + rc = str_read(&key, GFP_KERNEL, fp, len); + if (rc) + goto bad; + + if (len2) { + rc = str_read(&cladatum->comkey, GFP_KERNEL, fp, len2); + if (rc) + goto bad; + + rc = -EINVAL; + cladatum->comdatum = + symtab_search(&p->p_commons, cladatum->comkey); + if (!cladatum->comdatum) { + pr_err("SELinux: unknown common %s\n", + cladatum->comkey); + goto bad; + } + + /* + * security_get_permissions() maps the common's permissions + * into an array sized by this class's nprim, so a class must + * declare at least as many as the common it inherits. + */ + if (cladatum->permissions.nprim < + cladatum->comdatum->permissions.nprim) { + pr_err("SELinux: class %s has fewer permissions than common %s\n", + key, cladatum->comkey); + goto bad; + } + } + for (i = 0; i < nel; i++) { + rc = perm_read(p, &cladatum->permissions, fp, &claimed); + if (rc) + goto bad; + } + + /* the class's own permissions must claim the slots the common leaves */ + if (cladatum->comdatum) + inherited = cladatum->comdatum->permissions.nprim; + rc = -EINVAL; + if (claimed != (perm_claimed_mask(cladatum->permissions.nprim) & + ~perm_claimed_mask(inherited))) { + pr_err("SELinux: class %s does not define every permission it declares\n", + key); + goto bad; + } + + hash_eval(&cladatum->permissions.table, "class_permissions", key); + + rc = read_cons_helper(p, &cladatum->constraints, ncons, 0, fp); + if (rc) + goto bad; + + if (p->policyvers >= POLICYDB_VERSION_VALIDATETRANS) { + /* grab the validatetrans rules */ + rc = next_entry(buf, fp, sizeof(u32)); + if (rc) + goto bad; + ncons = le32_to_cpu(buf[0]); + rc = read_cons_helper(p, &cladatum->validatetrans, ncons, 1, + fp); + if (rc) + goto bad; + } + + if (p->policyvers >= POLICYDB_VERSION_NEW_OBJECT_DEFAULTS) { + rc = next_entry(buf, fp, sizeof(u32) * 3); + if (rc) + goto bad; + + rc = -EINVAL; + val = le32_to_cpu(buf[0]); + switch (val) { + case 0: + case DEFAULT_SOURCE: + case DEFAULT_TARGET: + cladatum->default_user = val; + break; + default: + goto bad; + } + val = le32_to_cpu(buf[1]); + switch (val) { + case 0: + case DEFAULT_SOURCE: + case DEFAULT_TARGET: + cladatum->default_role = val; + break; + default: + goto bad; + } + val = le32_to_cpu(buf[2]); + switch (val) { + case 0: + case DEFAULT_SOURCE_LOW: + case DEFAULT_SOURCE_HIGH: + case DEFAULT_SOURCE_LOW_HIGH: + case DEFAULT_TARGET_LOW: + case DEFAULT_TARGET_HIGH: + case DEFAULT_TARGET_LOW_HIGH: + case DEFAULT_GLBLUB: + cladatum->default_range = val; + break; + default: + goto bad; + } + } + + if (p->policyvers >= POLICYDB_VERSION_DEFAULT_TYPE) { + rc = next_entry(buf, fp, sizeof(u32) * 1); + if (rc) + goto bad; + rc = -EINVAL; + val = le32_to_cpu(buf[0]); + switch (val) { + case 0: + case DEFAULT_TARGET: + case DEFAULT_SOURCE: + cladatum->default_type = val; + break; + default: + goto bad; + } + } + + rc = symtab_insert(s, key, cladatum); + if (rc) + goto bad; + + return 0; +bad: + cls_destroy(key, cladatum, NULL); + if (rc) + pr_err("SELinux: invalid class\n"); + return rc; +} + +static int role_read(struct policydb *p, struct symtab *s, struct policy_file *fp) +{ + char *key = NULL; + struct role_datum *role; + int rc; + unsigned int to_read = 2; + __le32 buf[3]; + u32 len; + + role = kzalloc_obj(*role); + if (!role) + return -ENOMEM; + + if (p->policyvers >= POLICYDB_VERSION_BOUNDARY) + to_read = 3; + + rc = next_entry(buf, fp, sizeof(buf[0]) * to_read); + if (rc) + goto bad; + + len = le32_to_cpu(buf[0]); + role->value = le32_to_cpu(buf[1]); + if (p->policyvers >= POLICYDB_VERSION_BOUNDARY) + role->bounds = le32_to_cpu(buf[2]); + + rc = str_read(&key, GFP_KERNEL, fp, len); + if (rc) + goto bad; + + rc = ebitmap_read(&role->dominates, fp); + if (rc) + goto bad; + + rc = ebitmap_read(&role->types, fp); + if (rc) + goto bad; + + if (strcmp(key, OBJECT_R) == 0) { + rc = -EINVAL; + if (role->value != OBJECT_R_VAL) { + pr_err("SELinux: Role %s has wrong value %d\n", + OBJECT_R, role->value); + goto bad; + } + rc = 0; + goto bad; + } + + rc = symtab_insert(s, key, role); + if (rc) + goto bad; + return 0; +bad: + role_destroy(key, role, NULL); + return rc; +} + +static int type_read(struct policydb *p, struct symtab *s, struct policy_file *fp) +{ + char *key = NULL; + struct type_datum *typdatum; + int rc; + unsigned int to_read = 3; + __le32 buf[4]; + u32 len; + + typdatum = kzalloc_obj(*typdatum); + if (!typdatum) + return -ENOMEM; + + if (p->policyvers >= POLICYDB_VERSION_BOUNDARY) + to_read = 4; + + rc = next_entry(buf, fp, sizeof(buf[0]) * to_read); + if (rc) + goto bad; + + len = le32_to_cpu(buf[0]); + typdatum->value = le32_to_cpu(buf[1]); + if (p->policyvers >= POLICYDB_VERSION_BOUNDARY) { + u32 prop = le32_to_cpu(buf[2]); + + if (prop & TYPEDATUM_PROPERTY_PRIMARY) + typdatum->primary = 1; + if (prop & TYPEDATUM_PROPERTY_ATTRIBUTE) + typdatum->attribute = 1; + + typdatum->bounds = le32_to_cpu(buf[3]); + } else { + typdatum->primary = le32_to_cpu(buf[2]); + } + + rc = str_read(&key, GFP_KERNEL, fp, len); + if (rc) + goto bad; + + rc = symtab_insert(s, key, typdatum); + if (rc) + goto bad; + return 0; +bad: + type_destroy(key, typdatum, NULL); + return rc; +} + +/* + * Read a MLS level structure from a policydb binary + * representation file. + */ +static int mls_read_level(struct mls_level *lp, struct policy_file *fp) +{ + __le32 buf[1]; + int rc; + + memset(lp, 0, sizeof(*lp)); + + rc = next_entry(buf, fp, sizeof buf); + if (rc) { + pr_err("SELinux: mls: truncated level\n"); + return rc; + } + lp->sens = le32_to_cpu(buf[0]); + + rc = ebitmap_read(&lp->cat, fp); + if (rc) { + pr_err("SELinux: mls: error reading level categories\n"); + return rc; + } + return 0; +} + +static int user_read(struct policydb *p, struct symtab *s, struct policy_file *fp) +{ + char *key = NULL; + struct user_datum *usrdatum; + int rc; + unsigned int to_read = 2; + __le32 buf[3]; + u32 len; + + usrdatum = kzalloc_obj(*usrdatum); + if (!usrdatum) + return -ENOMEM; + + if (p->policyvers >= POLICYDB_VERSION_BOUNDARY) + to_read = 3; + + rc = next_entry(buf, fp, sizeof(buf[0]) * to_read); + if (rc) + goto bad; + + len = le32_to_cpu(buf[0]); + usrdatum->value = le32_to_cpu(buf[1]); + if (p->policyvers >= POLICYDB_VERSION_BOUNDARY) + usrdatum->bounds = le32_to_cpu(buf[2]); + + rc = str_read(&key, GFP_KERNEL, fp, len); + if (rc) + goto bad; + + rc = ebitmap_read(&usrdatum->roles, fp); + if (rc) + goto bad; + + if (p->policyvers >= POLICYDB_VERSION_MLS) { + rc = mls_read_range_helper(&usrdatum->range, fp); + if (rc) + goto bad; + rc = mls_read_level(&usrdatum->dfltlevel, fp); + if (rc) + goto bad; + } + + rc = symtab_insert(s, key, usrdatum); + if (rc) + goto bad; + return 0; +bad: + user_destroy(key, usrdatum, NULL); + return rc; +} + +static int sens_read(struct policydb *p, struct symtab *s, struct policy_file *fp) +{ + char *key = NULL; + struct level_datum *levdatum; + int rc; + __le32 buf[2]; + u32 len, val; + + levdatum = kzalloc_obj(*levdatum); + if (!levdatum) + return -ENOMEM; + + rc = next_entry(buf, fp, sizeof buf); + if (rc) + goto bad; + + len = le32_to_cpu(buf[0]); + val = le32_to_cpu(buf[1]); + rc = -EINVAL; + if (!val_is_boolean(val)) + goto bad; + levdatum->isalias = val; + + rc = str_read(&key, GFP_KERNEL, fp, len); + if (rc) + goto bad; + + rc = mls_read_level(&levdatum->level, fp); + if (rc) + goto bad; + + rc = symtab_insert(s, key, levdatum); + if (rc) + goto bad; + return 0; +bad: + sens_destroy(key, levdatum, NULL); + if (rc) + pr_err("SELinux: invalid sensitivity\n"); + return rc; +} + +static int cat_read(struct policydb *p, struct symtab *s, struct policy_file *fp) +{ + char *key = NULL; + struct cat_datum *catdatum; + int rc; + __le32 buf[3]; + u32 len, val; + + catdatum = kzalloc_obj(*catdatum); + if (!catdatum) + return -ENOMEM; + + rc = next_entry(buf, fp, sizeof buf); + if (rc) + goto bad; + + len = le32_to_cpu(buf[0]); + catdatum->value = le32_to_cpu(buf[1]); + val = le32_to_cpu(buf[2]); + rc = -EINVAL; + if (!val_is_boolean(val)) + goto bad; + catdatum->isalias = val; + + rc = str_read(&key, GFP_KERNEL, fp, len); + if (rc) + goto bad; + + rc = symtab_insert(s, key, catdatum); + if (rc) + goto bad; + return 0; +bad: + cat_destroy(key, catdatum, NULL); + if (rc) + pr_err("SELinux: invalid category\n"); + return rc; +} + +/* clang-format off */ +static int (*const read_f[SYM_NUM])(struct policydb *p, struct symtab *s, + struct policy_file *fp) = { + common_read, + class_read, + role_read, + type_read, + user_read, + cond_read_bool, + sens_read, + cat_read, +}; +/* clang-format on */ + +static int user_bounds_sanity_check(void *key, void *datum, void *datap) +{ + struct user_datum *upper, *user; + struct policydb *p = datap; + int depth = 0; + + upper = user = datum; + while (upper->bounds) { + struct ebitmap_node *node; + u32 bit; + + if (++depth == POLICYDB_BOUNDS_MAXDEPTH) { + pr_err("SELinux: user %s: " + "too deep or looped boundary\n", + (char *)key); + return -EINVAL; + } + + if (!policydb_user_isvalid(p, upper->bounds)) { + pr_err("SELinux: user %s: invalid boundary id %d\n", + (char *) key, upper->bounds); + return -EINVAL; + } + + upper = p->user_val_to_struct[upper->bounds - 1]; + ebitmap_for_each_positive_bit(&user->roles, node, bit) + { + if (ebitmap_get_bit(&upper->roles, bit)) + continue; + + pr_err("SELinux: boundary violated policy: " + "user=%s role=%s bounds=%s\n", + sym_name(p, SYM_USERS, user->value - 1), + sym_name(p, SYM_ROLES, bit), + sym_name(p, SYM_USERS, upper->value - 1)); + + return -EINVAL; + } + } + + return 0; +} + +static int role_bounds_sanity_check(void *key, void *datum, void *datap) +{ + struct role_datum *upper, *role; + struct policydb *p = datap; + int depth = 0; + + upper = role = datum; + while (upper->bounds) { + struct ebitmap_node *node; + u32 bit; + + if (++depth == POLICYDB_BOUNDS_MAXDEPTH) { + pr_err("SELinux: role %s: " + "too deep or looped bounds\n", + (char *)key); + return -EINVAL; + } + + if (!policydb_role_isvalid(p, upper->bounds)) { + pr_err("SELinux: role %s: invalid boundary id %d\n", + (char *) key, upper->bounds); + return -EINVAL; + } + + upper = p->role_val_to_struct[upper->bounds - 1]; + ebitmap_for_each_positive_bit(&role->types, node, bit) + { + if (ebitmap_get_bit(&upper->types, bit)) + continue; + + pr_err("SELinux: boundary violated policy: " + "role=%s type=%s bounds=%s\n", + sym_name(p, SYM_ROLES, role->value - 1), + sym_name(p, SYM_TYPES, bit), + sym_name(p, SYM_ROLES, upper->value - 1)); + + return -EINVAL; + } + } + + return 0; +} + +static int type_bounds_sanity_check(void *key, void *datum, void *datap) +{ + struct type_datum *upper; + struct policydb *p = datap; + int depth = 0; + + upper = datum; + while (upper->bounds) { + if (++depth == POLICYDB_BOUNDS_MAXDEPTH) { + pr_err("SELinux: type %s: " + "too deep or looped boundary\n", + (char *)key); + return -EINVAL; + } + + if (!policydb_type_isvalid(p, upper->bounds)) { + pr_err("SELinux: type %s: invalid boundary id %d\n", + (char *) key, upper->bounds); + return -EINVAL; + } + + upper = p->type_val_to_struct[upper->bounds - 1]; + if (upper->attribute) { + pr_err("SELinux: type %s: " + "bounded by attribute %s\n", + (char *)key, + sym_name(p, SYM_TYPES, upper->value - 1)); + return -EINVAL; + } + } + + return 0; +} + +static int policydb_bounds_sanity_check(struct policydb *p) +{ + int rc; + + if (p->policyvers < POLICYDB_VERSION_BOUNDARY) + return 0; + + rc = hashtab_map(&p->p_users.table, user_bounds_sanity_check, p); + if (rc) + return rc; + + rc = hashtab_map(&p->p_roles.table, role_bounds_sanity_check, p); + if (rc) + return rc; + + rc = hashtab_map(&p->p_types.table, type_bounds_sanity_check, p); + if (rc) + return rc; + + return 0; +} + +u16 string_to_security_class(struct policydb *p, const char *name) +{ + struct class_datum *cladatum; + + cladatum = symtab_search(&p->p_classes, name); + if (!cladatum) + return 0; + + return cladatum->value; +} + +u32 string_to_av_perm(struct policydb *p, u16 tclass, const char *name) +{ + struct class_datum *cladatum; + struct perm_datum *perdatum = NULL; + struct common_datum *comdatum; + + if (!tclass || tclass > p->p_classes.nprim) + return 0; + + cladatum = p->class_val_to_struct[tclass - 1]; + comdatum = cladatum->comdatum; + if (comdatum) + perdatum = symtab_search(&comdatum->permissions, name); + if (!perdatum) + perdatum = symtab_search(&cladatum->permissions, name); + if (!perdatum) + return 0; + + return 1U << (perdatum->value - 1); +} + +static int range_read(struct policydb *p, struct policy_file *fp) +{ + struct range_trans *rt = NULL; + struct mls_range *r = NULL; + int rc; + __le32 buf[2]; + u32 i, nel, val; + + if (p->policyvers < POLICYDB_VERSION_MLS) + return 0; + + rc = next_entry(buf, fp, sizeof(u32)); + if (rc) + return rc; + + nel = le32_to_cpu(buf[0]); + + /* we read at least 64 bytes and mls_read_range_helper() 32 bytes + * for any valid range-transition + */ + rc = size_check(3 * sizeof(u32), nel, fp); + if (rc) + return rc; + + rc = hashtab_init(&p->range_tr, nel); + if (rc) + return rc; + + for (i = 0; i < nel; i++) { + rc = -ENOMEM; + rt = kzalloc_obj(*rt); + if (!rt) + goto out; + + rc = next_entry(buf, fp, (sizeof(u32) * 2)); + if (rc) + goto out; + + rt->source_type = le32_to_cpu(buf[0]); + rt->target_type = le32_to_cpu(buf[1]); + if (p->policyvers >= POLICYDB_VERSION_RANGETRANS) { + rc = next_entry(buf, fp, sizeof(u32)); + if (rc) + goto out; + rc = -EINVAL; + val = le32_to_cpu(buf[0]); + if (val > U16_MAX) + goto out; + rt->target_class = val; + } else + rt->target_class = p->process_class; + + rc = -EINVAL; + if (!policydb_type_isvalid(p, rt->source_type) || + !policydb_type_isvalid(p, rt->target_type) || + !policydb_class_isvalid(p, rt->target_class)) + goto out; + + rc = -ENOMEM; + r = kzalloc_obj(*r); + if (!r) + goto out; + + rc = mls_read_range_helper(r, fp); + if (rc) + goto out; + + rc = -EINVAL; + if (!mls_range_isvalid(p, r)) { + pr_warn("SELinux: rangetrans: invalid range\n"); + goto out; + } + + rc = hashtab_insert(&p->range_tr, rt, r, rangetr_key_params); + if (rc) + goto out; + + rt = NULL; + r = NULL; + } + hash_eval(&p->range_tr, "rangetr", NULL); + rc = 0; +out: + kfree(rt); + kfree(r); + if (rc) + pr_err("SELinux: invalid range\n"); + return rc; +} + +static int filename_trans_read_helper_compat(struct policydb *p, struct policy_file *fp) +{ + struct filename_trans_key key, *ft = NULL; + struct filename_trans_datum *last, *datum = NULL; + char *name = NULL; + u32 len, stype, otype, val; + __le32 buf[4]; + int rc; + + /* length of the path component string */ + rc = next_entry(buf, fp, sizeof(u32)); + if (rc) + return rc; + len = le32_to_cpu(buf[0]); + + /* path component string */ + rc = str_read(&name, GFP_KERNEL, fp, len); + if (rc) + return rc; + + rc = next_entry(buf, fp, sizeof(u32) * 4); + if (rc) + goto out; + + rc = -EINVAL; + stype = le32_to_cpu(buf[0]); + if (!policydb_type_isvalid(p, stype)) + goto out; + key.ttype = le32_to_cpu(buf[1]); + if (!policydb_type_isvalid(p, key.ttype)) + goto out; + val = le32_to_cpu(buf[2]); + if (val > U16_MAX || !policydb_class_isvalid(p, val)) + goto out; + key.tclass = val; + key.name = name; + + otype = le32_to_cpu(buf[3]); + if (!policydb_simpletype_isvalid(p, otype)) + goto out; + + last = NULL; + datum = policydb_filenametr_search(p, &key); + while (datum) { + if (unlikely(ebitmap_get_bit(&datum->stypes, stype - 1))) { + /* conflicting/duplicate rules are ignored */ + datum = NULL; + rc = 0; + goto out; + } + if (likely(datum->otype == otype)) + break; + last = datum; + datum = datum->next; + } + if (!datum) { + rc = -ENOMEM; + datum = kmalloc_obj(*datum); + if (!datum) + goto out; + + ebitmap_init(&datum->stypes); + datum->otype = otype; + datum->next = NULL; + + if (unlikely(last)) { + last->next = datum; + } else { + rc = -ENOMEM; + ft = kmemdup(&key, sizeof(key), GFP_KERNEL); + if (!ft) + goto out; + + rc = hashtab_insert(&p->filename_trans, ft, datum, + filenametr_key_params); + if (rc) + goto out; + name = NULL; + + rc = ebitmap_set_bit(&p->filename_trans_ttypes, + key.ttype, 1); + if (rc) + return rc; + } + } + kfree(name); + return ebitmap_set_bit(&datum->stypes, stype - 1, 1); + +out: + kfree(ft); + kfree(name); + kfree(datum); + + if (rc) + pr_err("SELinux: invalid compat filename transition\n"); + return rc; +} + +static int filename_trans_read_helper(struct policydb *p, struct policy_file *fp) +{ + struct filename_trans_key *ft = NULL; + struct filename_trans_datum **dst, *datum, *first = NULL; + char *name = NULL; + u32 len, ttype, ndatum, i, val; + u16 tclass; + __le32 buf[3]; + int rc; + + /* length of the path component string */ + rc = next_entry(buf, fp, sizeof(u32)); + if (rc) + return rc; + len = le32_to_cpu(buf[0]); + + /* path component string */ + rc = str_read(&name, GFP_KERNEL, fp, len); + if (rc) + return rc; + + rc = next_entry(buf, fp, sizeof(u32) * 3); + if (rc) + goto out; + + rc = -EINVAL; + ttype = le32_to_cpu(buf[0]); + if (!policydb_type_isvalid(p, ttype)) + goto out; + val = le32_to_cpu(buf[1]); + rc = -EINVAL; + if (val > U16_MAX || !policydb_class_isvalid(p, val)) + goto out; + tclass = val; + + ndatum = le32_to_cpu(buf[2]); + if (ndatum == 0) { + pr_err("SELinux: Filename transition key with no datum\n"); + rc = -ENOENT; + goto out; + } + + dst = &first; + for (i = 0; i < ndatum; i++) { + rc = -ENOMEM; + datum = kmalloc_obj(*datum); + if (!datum) + goto out; + + datum->next = NULL; + *dst = datum; + + /* ebitmap_read() will at least init the bitmap */ + rc = ebitmap_read(&datum->stypes, fp); + if (rc) + goto out; + + rc = next_entry(buf, fp, sizeof(u32)); + if (rc) + goto out; + + datum->otype = le32_to_cpu(buf[0]); + + rc = -EINVAL; + if (!policydb_simpletype_isvalid(p, datum->otype)) + goto out; + + dst = &datum->next; + } + + rc = -ENOMEM; + ft = kmalloc_obj(*ft); + if (!ft) + goto out; + + ft->ttype = ttype; + ft->tclass = tclass; + ft->name = name; + + rc = hashtab_insert(&p->filename_trans, ft, first, + filenametr_key_params); + if (rc == -EEXIST) + pr_err("SELinux: Duplicate filename transition key\n"); + if (rc) + goto out; + + return ebitmap_set_bit(&p->filename_trans_ttypes, ttype, 1); + +out: + kfree(ft); + kfree(name); + while (first) { + datum = first; + first = first->next; + + ebitmap_destroy(&datum->stypes); + kfree(datum); + } + + if (rc) + pr_err("SELinux: invalid filename transition\n"); + return rc; +} + +static int filename_trans_read(struct policydb *p, struct policy_file *fp) +{ + u32 nel, i; + __le32 buf[1]; + int rc; + + if (p->policyvers < POLICYDB_VERSION_FILENAME_TRANS) + return 0; + + rc = next_entry(buf, fp, sizeof(u32)); + if (rc) + return rc; + nel = le32_to_cpu(buf[0]); + + if (p->policyvers < POLICYDB_VERSION_COMP_FTRANS) { + p->compat_filename_trans_count = nel; + + rc = hashtab_init(&p->filename_trans, (1 << 11)); + if (rc) + return rc; + + for (i = 0; i < nel; i++) { + rc = filename_trans_read_helper_compat(p, fp); + if (rc) + return rc; + } + } else { + rc = hashtab_init(&p->filename_trans, nel); + if (rc) + return rc; + + for (i = 0; i < nel; i++) { + rc = filename_trans_read_helper(p, fp); + if (rc) + return rc; + } + } + hash_eval(&p->filename_trans, "filenametr", NULL); + return 0; +} + +static int genfs_read(struct policydb *p, struct policy_file *fp) +{ + int rc; + u32 i, j, nel, nel2, len, len2, val; + __le32 buf[1]; + struct ocontext *l, *c; + struct ocontext *newc = NULL; + struct genfs *genfs_p, *genfs; + struct genfs *newgenfs = NULL; + + rc = next_entry(buf, fp, sizeof(u32)); + if (rc) + return rc; + nel = le32_to_cpu(buf[0]); + + for (i = 0; i < nel; i++) { + rc = next_entry(buf, fp, sizeof(u32)); + if (rc) + goto out; + len = le32_to_cpu(buf[0]); + + rc = -ENOMEM; + newgenfs = kzalloc_obj(*newgenfs); + if (!newgenfs) + goto out; + + rc = str_read(&newgenfs->fstype, GFP_KERNEL, fp, len); + if (rc) + goto out; + + for (genfs_p = NULL, genfs = p->genfs; genfs; + genfs_p = genfs, genfs = genfs->next) { + rc = -EINVAL; + if (strcmp(newgenfs->fstype, genfs->fstype) == 0) { + pr_err("SELinux: dup genfs fstype %s\n", + newgenfs->fstype); + goto out; + } + if (strcmp(newgenfs->fstype, genfs->fstype) < 0) + break; + } + newgenfs->next = genfs; + if (genfs_p) + genfs_p->next = newgenfs; + else + p->genfs = newgenfs; + genfs = newgenfs; + newgenfs = NULL; + + rc = next_entry(buf, fp, sizeof(u32)); + if (rc) + goto out; + + nel2 = le32_to_cpu(buf[0]); + for (j = 0; j < nel2; j++) { + rc = next_entry(buf, fp, sizeof(u32)); + if (rc) + goto out; + len = le32_to_cpu(buf[0]); + + rc = -ENOMEM; + newc = kzalloc_obj(*newc); + if (!newc) + goto out; + + rc = str_read(&newc->u.name, GFP_KERNEL, fp, len); + if (rc) + goto out; + + rc = next_entry(buf, fp, sizeof(u32)); + if (rc) + goto out; + + rc = -EINVAL; + val = le32_to_cpu(buf[0]); + if (val > U16_MAX || (val != 0 && !policydb_class_isvalid(p, val))) + goto out; + newc->v.sclass = val; + rc = context_read_and_validate(&newc->context[0], p, + fp); + if (rc) + goto out; + + for (l = NULL, c = genfs->head; c; l = c, c = c->next) { + rc = -EINVAL; + if (!strcmp(newc->u.name, c->u.name) && + (!c->v.sclass || !newc->v.sclass || + newc->v.sclass == c->v.sclass)) { + pr_err("SELinux: dup genfs entry (%s,%s)\n", + genfs->fstype, c->u.name); + goto out; + } + len = strlen(newc->u.name); + len2 = strlen(c->u.name); + if (len > len2) + break; + } + + newc->next = c; + if (l) + l->next = newc; + else + genfs->head = newc; + newc = NULL; + } + } + rc = 0; +out: + if (newgenfs) { + kfree(newgenfs->fstype); + kfree(newgenfs); + } + ocontext_destroy(newc, OCON_FSUSE); + + if (rc) + pr_err("SELinux: invalid genfs\n"); + + return rc; +} + +static int ocontext_read(struct policydb *p, + const struct policydb_compat_info *info, struct policy_file *fp) +{ + int rc; + unsigned int i; + u32 j, nel, len, val; + __be64 prefixbuf[1]; + __le32 buf[3]; + struct ocontext *l, *c; + u32 nodebuf[8]; + + for (i = 0; i < info->ocon_num; i++) { + rc = next_entry(buf, fp, sizeof(u32)); + if (rc) + goto out; + nel = le32_to_cpu(buf[0]); + + l = NULL; + for (j = 0; j < nel; j++) { + rc = -ENOMEM; + c = kzalloc_obj(*c); + if (!c) + goto out; + if (l) + l->next = c; + else + p->ocontexts[i] = c; + l = c; + + switch (i) { + case OCON_ISID: + rc = next_entry(buf, fp, sizeof(u32)); + if (rc) + goto out; + + c->sid[0] = le32_to_cpu(buf[0]); + rc = context_read_and_validate(&c->context[0], + p, fp); + if (rc) + goto out; + break; + case OCON_FS: + case OCON_NETIF: + rc = next_entry(buf, fp, sizeof(u32)); + if (rc) + goto out; + len = le32_to_cpu(buf[0]); + + rc = str_read(&c->u.name, GFP_KERNEL, fp, len); + if (rc) + goto out; + + if (i == OCON_FS) + pr_warn("SELinux: void and deprecated fs ocon %s\n", + c->u.name); + + rc = context_read_and_validate(&c->context[0], + p, fp); + if (rc) + goto out; + rc = context_read_and_validate(&c->context[1], + p, fp); + if (rc) + goto out; + break; + case OCON_PORT: + rc = next_entry(buf, fp, sizeof(u32) * 3); + if (rc) + goto out; + + rc = -EINVAL; + val = le32_to_cpu(buf[0]); + if (val > U8_MAX) + goto out; + c->u.port.protocol = val; + val = le32_to_cpu(buf[1]); + if (val > U16_MAX) + goto out; + c->u.port.low_port = val; + val = le32_to_cpu(buf[2]); + if (val > U16_MAX) + goto out; + c->u.port.high_port = val; + if (c->u.port.low_port == 0 || + c->u.port.low_port > c->u.port.high_port) + goto out; + + rc = context_read_and_validate(&c->context[0], p, fp); + if (rc) + goto out; + break; + case OCON_NODE: + rc = next_entry(nodebuf, fp, sizeof(u32) * 2); + if (rc) + goto out; + c->u.node.addr = nodebuf[0]; /* network order */ + c->u.node.mask = nodebuf[1]; /* network order */ + rc = context_read_and_validate(&c->context[0], + p, fp); + if (rc) + goto out; + break; + case OCON_FSUSE: + rc = next_entry(buf, fp, sizeof(u32) * 2); + if (rc) + goto out; + + rc = -EINVAL; + c->v.behavior = le32_to_cpu(buf[0]); + /* Determined at runtime, not in policy DB. */ + if (c->v.behavior == SECURITY_FS_USE_MNTPOINT) + goto out; + if (c->v.behavior > SECURITY_FS_USE_MAX) + goto out; + + len = le32_to_cpu(buf[1]); + rc = str_read(&c->u.name, GFP_KERNEL, fp, len); + if (rc) + goto out; + + rc = context_read_and_validate(&c->context[0], + p, fp); + if (rc) + goto out; + break; + case OCON_NODE6: { + int k; + + rc = next_entry(nodebuf, fp, sizeof(u32) * 8); + if (rc) + goto out; + for (k = 0; k < 4; k++) + c->u.node6.addr[k] = nodebuf[k]; + for (k = 0; k < 4; k++) + c->u.node6.mask[k] = nodebuf[k + 4]; + rc = context_read_and_validate(&c->context[0], + p, fp); + if (rc) + goto out; + break; + } + case OCON_IBPKEY: { + u32 pkey_lo, pkey_hi; + + rc = next_entry(prefixbuf, fp, sizeof(u64)); + if (rc) + goto out; + + /* we need to have subnet_prefix in CPU order */ + c->u.ibpkey.subnet_prefix = + be64_to_cpu(prefixbuf[0]); + + rc = next_entry(buf, fp, sizeof(u32) * 2); + if (rc) + goto out; + + pkey_lo = le32_to_cpu(buf[0]); + pkey_hi = le32_to_cpu(buf[1]); + + if (pkey_lo > U16_MAX || pkey_hi > U16_MAX) { + rc = -EINVAL; + goto out; + } + + c->u.ibpkey.low_pkey = pkey_lo; + c->u.ibpkey.high_pkey = pkey_hi; + + rc = context_read_and_validate(&c->context[0], + p, fp); + if (rc) + goto out; + break; + } + case OCON_IBENDPORT: { + u32 port; + + rc = next_entry(buf, fp, sizeof(u32) * 2); + if (rc) + goto out; + len = le32_to_cpu(buf[0]); + + rc = str_read(&c->u.ibendport.dev_name, + GFP_KERNEL, fp, len); + if (rc) + goto out; + + port = le32_to_cpu(buf[1]); + if (port > U8_MAX || port == 0) { + rc = -EINVAL; + goto out; + } + + c->u.ibendport.port = port; + + rc = context_read_and_validate(&c->context[0], + p, fp); + if (rc) + goto out; + break; + } /* end case */ + } /* end switch */ + } + } + rc = 0; +out: + if (rc) + pr_err("SELinux: invalid ocon\n"); + return rc; +} + +/* + * Read the configuration data from a policy database binary + * representation file into a policy database structure. + */ +int policydb_read(struct policydb *p, struct policy_file *fp) +{ + struct role_allow *ra, *lra; + struct role_trans_key *rtk = NULL; + struct role_trans_datum *rtd = NULL; + int rc; + __le32 buf[4]; + u32 i, j, len, nprim, nel, perm, val; + + char *policydb_str; + const struct policydb_compat_info *info; + + policydb_init(p); + + /* Read the magic number and string length. */ + rc = next_entry(buf, fp, sizeof(u32) * 2); + if (rc) + goto bad; + + rc = -EINVAL; + if (le32_to_cpu(buf[0]) != POLICYDB_MAGIC) { + pr_err("SELinux: policydb magic number 0x%x does " + "not match expected magic number 0x%x\n", + le32_to_cpu(buf[0]), POLICYDB_MAGIC); + goto bad; + } + + rc = -EINVAL; + len = le32_to_cpu(buf[1]); + if (len != strlen(POLICYDB_STRING)) { + pr_err("SELinux: policydb string length %d does not " + "match expected length %zu\n", + len, strlen(POLICYDB_STRING)); + goto bad; + } + + rc = str_read(&policydb_str, GFP_KERNEL, fp, len); + if (rc) { + if (rc == -ENOMEM) { + pr_err("SELinux: unable to allocate memory for policydb string of length %d\n", + len); + } else { + pr_err("SELinux: truncated policydb string identifier\n"); + } + goto bad; + } + + rc = -EINVAL; + if (strcmp(policydb_str, POLICYDB_STRING)) { + pr_err("SELinux: policydb string %s does not match " + "my string %s\n", + policydb_str, POLICYDB_STRING); + kfree(policydb_str); + goto bad; + } + /* Done with policydb_str. */ + kfree(policydb_str); + policydb_str = NULL; + + /* Read the version and table sizes. */ + rc = next_entry(buf, fp, sizeof(u32) * 4); + if (rc) + goto bad; + + rc = -EINVAL; + p->policyvers = le32_to_cpu(buf[0]); + if (p->policyvers < POLICYDB_VERSION_MIN || + p->policyvers > POLICYDB_VERSION_MAX) { + pr_err("SELinux: policydb version %d does not match " + "my version range %d-%d\n", + le32_to_cpu(buf[0]), POLICYDB_VERSION_MIN, + POLICYDB_VERSION_MAX); + goto bad; + } + + if ((le32_to_cpu(buf[1]) & POLICYDB_CONFIG_MLS)) { + p->mls_enabled = 1; + + rc = -EINVAL; + if (p->policyvers < POLICYDB_VERSION_MLS) { + pr_err("SELinux: security policydb version %d " + "(MLS) not backwards compatible\n", + p->policyvers); + goto bad; + } + } + p->reject_unknown = !!(le32_to_cpu(buf[1]) & REJECT_UNKNOWN); + p->allow_unknown = !!(le32_to_cpu(buf[1]) & ALLOW_UNKNOWN); + + if (p->policyvers >= POLICYDB_VERSION_POLCAP) { + rc = ebitmap_read(&p->policycaps, fp); + if (rc) + goto bad; + } + + if (p->policyvers >= POLICYDB_VERSION_PERMISSIVE) { + rc = ebitmap_read(&p->permissive_map, fp); + if (rc) + goto bad; + } + + if (p->policyvers >= POLICYDB_VERSION_NEVERAUDIT) { + rc = ebitmap_read(&p->neveraudit_map, fp); + if (rc) + goto bad; + } + + rc = -EINVAL; + info = policydb_lookup_compat(p->policyvers); + if (!info) { + pr_err("SELinux: unable to find policy compat info " + "for version %d\n", + p->policyvers); + goto bad; + } + + rc = -EINVAL; + if (le32_to_cpu(buf[2]) != info->sym_num || + le32_to_cpu(buf[3]) != info->ocon_num) { + pr_err("SELinux: policydb table sizes (%d,%d) do " + "not match mine (%d,%d)\n", + le32_to_cpu(buf[2]), le32_to_cpu(buf[3]), info->sym_num, + info->ocon_num); + goto bad; + } + + for (i = 0; i < info->sym_num; i++) { + rc = next_entry(buf, fp, sizeof(u32) * 2); + if (rc) + goto bad; + nprim = le32_to_cpu(buf[0]); + nel = le32_to_cpu(buf[1]); + + /* every read_f() implementation reads at least 128 bytes + * for any valid entry + */ + rc = size_check(4 * sizeof(u32), nel, fp); + if (rc) + goto out; + + rc = symtab_init(&p->symtab[i], nel); + if (rc) + goto out; + + if (i == SYM_ROLES) { + rc = roles_init(p); + if (rc) + goto out; + } + + for (j = 0; j < nel; j++) { + rc = read_f[i](p, &p->symtab[i], fp); + if (rc) + goto bad; + } + + p->symtab[i].nprim = nprim; + } + + rc = policydb_index(p); + if (rc) + goto bad; + + rc = -EINVAL; + p->process_class = string_to_security_class(p, "process"); + if (!p->process_class) { + pr_err("SELinux: process class is required, not defined in policy\n"); + goto bad; + } + + rc = avtab_read(&p->te_avtab, fp, p); + if (rc) + goto bad; + + avtab_hash_eval(&p->te_avtab, "rules"); + + if (p->policyvers >= POLICYDB_VERSION_BOOL) { + rc = cond_read_list(p, fp); + if (rc) + goto bad; + } + + rc = next_entry(buf, fp, sizeof(u32)); + if (rc) + goto bad; + nel = le32_to_cpu(buf[0]); + + /* we read at least 96 bytes for any valid role-transition */ + rc = size_check(3 * sizeof(u32), nel, fp); + if (rc) + goto bad; + + rc = hashtab_init(&p->role_tr, nel); + if (rc) + goto bad; + for (i = 0; i < nel; i++) { + rc = -ENOMEM; + rtk = kmalloc_obj(*rtk); + if (!rtk) + goto bad; + + rc = -ENOMEM; + rtd = kmalloc_obj(*rtd); + if (!rtd) + goto bad; + + rc = next_entry(buf, fp, sizeof(u32) * 3); + if (rc) + goto bad; + + rtk->role = le32_to_cpu(buf[0]); + rtk->type = le32_to_cpu(buf[1]); + rtd->new_role = le32_to_cpu(buf[2]); + if (p->policyvers >= POLICYDB_VERSION_ROLETRANS) { + rc = next_entry(buf, fp, sizeof(u32)); + if (rc) + goto bad; + rc = -EINVAL; + val = le32_to_cpu(buf[0]); + if (val > U16_MAX) + goto bad; + rtk->tclass = val; + } else + rtk->tclass = p->process_class; + + rc = -EINVAL; + if (!policydb_role_isvalid(p, rtk->role) || + !policydb_type_isvalid(p, rtk->type) || + !policydb_class_isvalid(p, rtk->tclass) || + !policydb_role_isvalid(p, rtd->new_role)) + goto bad; + + rc = hashtab_insert(&p->role_tr, rtk, rtd, roletr_key_params); + if (rc) + goto bad; + + rtk = NULL; + rtd = NULL; + } + + hash_eval(&p->role_tr, "roletr", NULL); + + rc = next_entry(buf, fp, sizeof(u32)); + if (rc) + goto bad; + nel = le32_to_cpu(buf[0]); + lra = NULL; + for (i = 0; i < nel; i++) { + rc = -ENOMEM; + ra = kzalloc_obj(*ra); + if (!ra) + goto bad; + if (lra) + lra->next = ra; + else + p->role_allow = ra; + rc = next_entry(buf, fp, sizeof(u32) * 2); + if (rc) + goto bad; + + rc = -EINVAL; + ra->role = le32_to_cpu(buf[0]); + ra->new_role = le32_to_cpu(buf[1]); + if (!policydb_role_isvalid(p, ra->role) || + !policydb_role_isvalid(p, ra->new_role)) + goto bad; + lra = ra; + } + + rc = filename_trans_read(p, fp); + if (rc) + goto bad; + + rc = -EINVAL; + perm = string_to_av_perm(p, p->process_class, "transition"); + if (!perm) { + pr_err("SELinux: process transition permission is required, not defined in policy\n"); + goto bad; + } + p->process_trans_perms = perm; + perm = string_to_av_perm(p, p->process_class, "dyntransition"); + if (!perm) { + pr_err("SELinux: process dyntransition permission is required, not defined in policy\n"); + goto bad; + } + p->process_trans_perms |= perm; + + rc = ocontext_read(p, info, fp); + if (rc) + goto bad; + + rc = genfs_read(p, fp); + if (rc) + goto bad; + + rc = range_read(p, fp); + if (rc) + goto bad; + + rc = -ENOMEM; + p->type_attr_map_array = kvzalloc_objs(*p->type_attr_map_array, + p->p_types.nprim); + if (!p->type_attr_map_array) + goto bad; + + /* just in case ebitmap_init() becomes more than just a memset(0): */ + for (i = 0; i < p->p_types.nprim; i++) + ebitmap_init(&p->type_attr_map_array[i]); + + for (i = 0; i < p->p_types.nprim; i++) { + struct ebitmap *e = &p->type_attr_map_array[i]; + + if (p->policyvers >= POLICYDB_VERSION_AVTAB) { + rc = ebitmap_read(e, fp); + if (rc) + goto bad; + } + + rc = -EINVAL; + if (ebitmap_get_highest_set_bit(e) >= p->p_types.nprim) + goto bad; + + /* add the type itself as the degenerate case */ + rc = ebitmap_set_bit(e, i, 1); + if (rc) + goto bad; + } + + rc = policydb_bounds_sanity_check(p); + if (rc) + goto bad; + + rc = 0; +out: + return rc; +bad: + kfree(rtk); + kfree(rtd); + policydb_destroy(p); + goto out; +} + +/* + * Write a MLS level structure to a policydb binary + * representation file. + */ +static int mls_write_level(struct mls_level *l, struct policy_file *fp) +{ + __le32 buf[1]; + int rc; + + buf[0] = cpu_to_le32(l->sens); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + + rc = ebitmap_write(&l->cat, fp); + if (rc) + return rc; + + return 0; +} + +/* + * Write a MLS range structure to a policydb binary + * representation file. + */ +static int mls_write_range_helper(struct mls_range *r, struct policy_file *fp) +{ + __le32 buf[3]; + size_t items; + int rc, eq; + + eq = mls_level_eq(&r->level[1], &r->level[0]); + + if (eq) + items = 2; + else + items = 3; + buf[0] = cpu_to_le32(items - 1); + buf[1] = cpu_to_le32(r->level[0].sens); + if (!eq) + buf[2] = cpu_to_le32(r->level[1].sens); + + BUG_ON(items > ARRAY_SIZE(buf)); + + rc = put_entry(buf, sizeof(u32), items, fp); + if (rc) + return rc; + + rc = ebitmap_write(&r->level[0].cat, fp); + if (rc) + return rc; + if (!eq) { + rc = ebitmap_write(&r->level[1].cat, fp); + if (rc) + return rc; + } + + return 0; +} + +static int sens_write(void *vkey, void *datum, void *ptr) +{ + char *key = vkey; + struct level_datum *levdatum = datum; + struct policy_data *pd = ptr; + struct policy_file *fp = pd->fp; + __le32 buf[2]; + size_t len; + int rc; + + len = strlen(key); + buf[0] = cpu_to_le32(len); + buf[1] = cpu_to_le32(levdatum->isalias); + rc = put_entry(buf, sizeof(u32), 2, fp); + if (rc) + return rc; + + rc = put_entry(key, 1, len, fp); + if (rc) + return rc; + + rc = mls_write_level(&levdatum->level, fp); + if (rc) + return rc; + + return 0; +} + +static int cat_write(void *vkey, void *datum, void *ptr) +{ + char *key = vkey; + struct cat_datum *catdatum = datum; + struct policy_data *pd = ptr; + struct policy_file *fp = pd->fp; + __le32 buf[3]; + size_t len; + int rc; + + len = strlen(key); + buf[0] = cpu_to_le32(len); + buf[1] = cpu_to_le32(catdatum->value); + buf[2] = cpu_to_le32(catdatum->isalias); + rc = put_entry(buf, sizeof(u32), 3, fp); + if (rc) + return rc; + + rc = put_entry(key, 1, len, fp); + if (rc) + return rc; + + return 0; +} + +static int role_trans_write_one(void *key, void *datum, void *ptr) +{ + struct role_trans_key *rtk = key; + struct role_trans_datum *rtd = datum; + struct policy_data *pd = ptr; + struct policy_file *fp = pd->fp; + struct policydb *p = pd->p; + __le32 buf[3]; + int rc; + + buf[0] = cpu_to_le32(rtk->role); + buf[1] = cpu_to_le32(rtk->type); + buf[2] = cpu_to_le32(rtd->new_role); + rc = put_entry(buf, sizeof(u32), 3, fp); + if (rc) + return rc; + if (p->policyvers >= POLICYDB_VERSION_ROLETRANS) { + buf[0] = cpu_to_le32(rtk->tclass); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + } + return 0; +} + +static int role_trans_write(struct policydb *p, struct policy_file *fp) +{ + struct policy_data pd = { .p = p, .fp = fp }; + __le32 buf[1]; + int rc; + + buf[0] = cpu_to_le32(p->role_tr.nel); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + + return hashtab_map(&p->role_tr, role_trans_write_one, &pd); +} + +static int role_allow_write(struct role_allow *r, struct policy_file *fp) +{ + struct role_allow *ra; + __le32 buf[2]; + size_t nel; + int rc; + + nel = 0; + for (ra = r; ra; ra = ra->next) + nel++; + buf[0] = cpu_to_le32(nel); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + for (ra = r; ra; ra = ra->next) { + buf[0] = cpu_to_le32(ra->role); + buf[1] = cpu_to_le32(ra->new_role); + rc = put_entry(buf, sizeof(u32), 2, fp); + if (rc) + return rc; + } + return 0; +} + +/* + * Write a security context structure + * to a policydb binary representation file. + */ +static int context_write(struct policydb *p, struct context *c, struct policy_file *fp) +{ + int rc; + __le32 buf[3]; + + buf[0] = cpu_to_le32(c->user); + buf[1] = cpu_to_le32(c->role); + buf[2] = cpu_to_le32(c->type); + + rc = put_entry(buf, sizeof(u32), 3, fp); + if (rc) + return rc; + + rc = mls_write_range_helper(&c->range, fp); + if (rc) + return rc; + + return 0; +} + +/* + * The following *_write functions are used to + * write the symbol data to a policy database + * binary representation file. + */ + +static int perm_write(void *vkey, void *datum, void *fp) +{ + char *key = vkey; + struct perm_datum *perdatum = datum; + __le32 buf[2]; + size_t len; + int rc; + + len = strlen(key); + buf[0] = cpu_to_le32(len); + buf[1] = cpu_to_le32(perdatum->value); + rc = put_entry(buf, sizeof(u32), 2, fp); + if (rc) + return rc; + + rc = put_entry(key, 1, len, fp); + if (rc) + return rc; + + return 0; +} + +static int common_write(void *vkey, void *datum, void *ptr) +{ + char *key = vkey; + struct common_datum *comdatum = datum; + struct policy_data *pd = ptr; + struct policy_file *fp = pd->fp; + __le32 buf[4]; + size_t len; + int rc; + + len = strlen(key); + buf[0] = cpu_to_le32(len); + buf[1] = cpu_to_le32(comdatum->value); + buf[2] = cpu_to_le32(comdatum->permissions.nprim); + buf[3] = cpu_to_le32(comdatum->permissions.table.nel); + rc = put_entry(buf, sizeof(u32), 4, fp); + if (rc) + return rc; + + rc = put_entry(key, 1, len, fp); + if (rc) + return rc; + + rc = hashtab_map(&comdatum->permissions.table, perm_write, fp); + if (rc) + return rc; + + return 0; +} + +static int type_set_write(struct type_set *t, struct policy_file *fp) +{ + int rc; + __le32 buf[1]; + + if (ebitmap_write(&t->types, fp)) + return -EINVAL; + if (ebitmap_write(&t->negset, fp)) + return -EINVAL; + + buf[0] = cpu_to_le32(t->flags); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return -EINVAL; + + return 0; +} + +static int write_cons_helper(struct policydb *p, struct constraint_node *node, + struct policy_file *fp) +{ + struct constraint_node *c; + struct constraint_expr *e; + __le32 buf[3]; + u32 nel; + int rc; + + for (c = node; c; c = c->next) { + nel = 0; + for (e = c->expr; e; e = e->next) + nel++; + buf[0] = cpu_to_le32(c->permissions); + buf[1] = cpu_to_le32(nel); + rc = put_entry(buf, sizeof(u32), 2, fp); + if (rc) + return rc; + for (e = c->expr; e; e = e->next) { + buf[0] = cpu_to_le32(e->expr_type); + buf[1] = cpu_to_le32(e->attr); + buf[2] = cpu_to_le32(e->op); + rc = put_entry(buf, sizeof(u32), 3, fp); + if (rc) + return rc; + + switch (e->expr_type) { + case CEXPR_NAMES: + rc = ebitmap_write(&e->names, fp); + if (rc) + return rc; + if (p->policyvers >= + POLICYDB_VERSION_CONSTRAINT_NAMES) { + rc = type_set_write(e->type_names, fp); + if (rc) + return rc; + } + break; + default: + break; + } + } + } + + return 0; +} + +static int class_write(void *vkey, void *datum, void *ptr) +{ + char *key = vkey; + struct class_datum *cladatum = datum; + struct policy_data *pd = ptr; + struct policy_file *fp = pd->fp; + struct policydb *p = pd->p; + struct constraint_node *c; + __le32 buf[6]; + u32 ncons; + size_t len, len2; + int rc; + + len = strlen(key); + if (cladatum->comkey) + len2 = strlen(cladatum->comkey); + else + len2 = 0; + + ncons = 0; + for (c = cladatum->constraints; c; c = c->next) + ncons++; + + buf[0] = cpu_to_le32(len); + buf[1] = cpu_to_le32(len2); + buf[2] = cpu_to_le32(cladatum->value); + buf[3] = cpu_to_le32(cladatum->permissions.nprim); + buf[4] = cpu_to_le32(cladatum->permissions.table.nel); + buf[5] = cpu_to_le32(ncons); + rc = put_entry(buf, sizeof(u32), 6, fp); + if (rc) + return rc; + + rc = put_entry(key, 1, len, fp); + if (rc) + return rc; + + if (cladatum->comkey) { + rc = put_entry(cladatum->comkey, 1, len2, fp); + if (rc) + return rc; + } + + rc = hashtab_map(&cladatum->permissions.table, perm_write, fp); + if (rc) + return rc; + + rc = write_cons_helper(p, cladatum->constraints, fp); + if (rc) + return rc; + + /* write out the validatetrans rule */ + ncons = 0; + for (c = cladatum->validatetrans; c; c = c->next) + ncons++; + + buf[0] = cpu_to_le32(ncons); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + + rc = write_cons_helper(p, cladatum->validatetrans, fp); + if (rc) + return rc; + + if (p->policyvers >= POLICYDB_VERSION_NEW_OBJECT_DEFAULTS) { + buf[0] = cpu_to_le32(cladatum->default_user); + buf[1] = cpu_to_le32(cladatum->default_role); + buf[2] = cpu_to_le32(cladatum->default_range); + + rc = put_entry(buf, sizeof(uint32_t), 3, fp); + if (rc) + return rc; + } + + if (p->policyvers >= POLICYDB_VERSION_DEFAULT_TYPE) { + buf[0] = cpu_to_le32(cladatum->default_type); + rc = put_entry(buf, sizeof(uint32_t), 1, fp); + if (rc) + return rc; + } + + return 0; +} + +static int role_write(void *vkey, void *datum, void *ptr) +{ + char *key = vkey; + struct role_datum *role = datum; + struct policy_data *pd = ptr; + struct policy_file *fp = pd->fp; + struct policydb *p = pd->p; + __le32 buf[3]; + size_t items, len; + int rc; + + len = strlen(key); + items = 0; + buf[items++] = cpu_to_le32(len); + buf[items++] = cpu_to_le32(role->value); + if (p->policyvers >= POLICYDB_VERSION_BOUNDARY) + buf[items++] = cpu_to_le32(role->bounds); + + BUG_ON(items > ARRAY_SIZE(buf)); + + rc = put_entry(buf, sizeof(u32), items, fp); + if (rc) + return rc; + + rc = put_entry(key, 1, len, fp); + if (rc) + return rc; + + rc = ebitmap_write(&role->dominates, fp); + if (rc) + return rc; + + rc = ebitmap_write(&role->types, fp); + if (rc) + return rc; + + return 0; +} + +static int type_write(void *vkey, void *datum, void *ptr) +{ + char *key = vkey; + struct type_datum *typdatum = datum; + struct policy_data *pd = ptr; + struct policydb *p = pd->p; + struct policy_file *fp = pd->fp; + __le32 buf[4]; + int rc; + size_t items, len; + + len = strlen(key); + items = 0; + buf[items++] = cpu_to_le32(len); + buf[items++] = cpu_to_le32(typdatum->value); + if (p->policyvers >= POLICYDB_VERSION_BOUNDARY) { + u32 properties = 0; + + if (typdatum->primary) + properties |= TYPEDATUM_PROPERTY_PRIMARY; + + if (typdatum->attribute) + properties |= TYPEDATUM_PROPERTY_ATTRIBUTE; + + buf[items++] = cpu_to_le32(properties); + buf[items++] = cpu_to_le32(typdatum->bounds); + } else { + buf[items++] = cpu_to_le32(typdatum->primary); + } + BUG_ON(items > ARRAY_SIZE(buf)); + rc = put_entry(buf, sizeof(u32), items, fp); + if (rc) + return rc; + + rc = put_entry(key, 1, len, fp); + if (rc) + return rc; + + return 0; +} + +static int user_write(void *vkey, void *datum, void *ptr) +{ + char *key = vkey; + struct user_datum *usrdatum = datum; + struct policy_data *pd = ptr; + struct policydb *p = pd->p; + struct policy_file *fp = pd->fp; + __le32 buf[3]; + size_t items, len; + int rc; + + len = strlen(key); + items = 0; + buf[items++] = cpu_to_le32(len); + buf[items++] = cpu_to_le32(usrdatum->value); + if (p->policyvers >= POLICYDB_VERSION_BOUNDARY) + buf[items++] = cpu_to_le32(usrdatum->bounds); + BUG_ON(items > ARRAY_SIZE(buf)); + rc = put_entry(buf, sizeof(u32), items, fp); + if (rc) + return rc; + + rc = put_entry(key, 1, len, fp); + if (rc) + return rc; + + rc = ebitmap_write(&usrdatum->roles, fp); + if (rc) + return rc; + + rc = mls_write_range_helper(&usrdatum->range, fp); + if (rc) + return rc; + + rc = mls_write_level(&usrdatum->dfltlevel, fp); + if (rc) + return rc; + + return 0; +} + +/* clang-format off */ +static int (*const write_f[SYM_NUM])(void *key, void *datum, void *datap) = { + common_write, + class_write, + role_write, + type_write, + user_write, + cond_write_bool, + sens_write, + cat_write, +}; +/* clang-format on */ + +static int ocontext_write(struct policydb *p, + const struct policydb_compat_info *info, + struct policy_file *fp) +{ + unsigned int i, j; + int rc; + size_t nel, len; + __be64 prefixbuf[1]; + __le32 buf[3]; + u32 nodebuf[8]; + struct ocontext *c; + for (i = 0; i < info->ocon_num; i++) { + nel = 0; + for (c = p->ocontexts[i]; c; c = c->next) + nel++; + buf[0] = cpu_to_le32(nel); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + for (c = p->ocontexts[i]; c; c = c->next) { + switch (i) { + case OCON_ISID: + buf[0] = cpu_to_le32(c->sid[0]); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + rc = context_write(p, &c->context[0], fp); + if (rc) + return rc; + break; + case OCON_FS: + case OCON_NETIF: + len = strlen(c->u.name); + buf[0] = cpu_to_le32(len); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + rc = put_entry(c->u.name, 1, len, fp); + if (rc) + return rc; + rc = context_write(p, &c->context[0], fp); + if (rc) + return rc; + rc = context_write(p, &c->context[1], fp); + if (rc) + return rc; + break; + case OCON_PORT: + buf[0] = cpu_to_le32(c->u.port.protocol); + buf[1] = cpu_to_le32(c->u.port.low_port); + buf[2] = cpu_to_le32(c->u.port.high_port); + rc = put_entry(buf, sizeof(u32), 3, fp); + if (rc) + return rc; + rc = context_write(p, &c->context[0], fp); + if (rc) + return rc; + break; + case OCON_NODE: + nodebuf[0] = c->u.node.addr; /* network order */ + nodebuf[1] = c->u.node.mask; /* network order */ + rc = put_entry(nodebuf, sizeof(u32), 2, fp); + if (rc) + return rc; + rc = context_write(p, &c->context[0], fp); + if (rc) + return rc; + break; + case OCON_FSUSE: + buf[0] = cpu_to_le32(c->v.behavior); + len = strlen(c->u.name); + buf[1] = cpu_to_le32(len); + rc = put_entry(buf, sizeof(u32), 2, fp); + if (rc) + return rc; + rc = put_entry(c->u.name, 1, len, fp); + if (rc) + return rc; + rc = context_write(p, &c->context[0], fp); + if (rc) + return rc; + break; + case OCON_NODE6: + for (j = 0; j < 4; j++) + nodebuf[j] = + c->u.node6.addr + [j]; /* network order */ + for (j = 0; j < 4; j++) + nodebuf[j + 4] = + c->u.node6.mask + [j]; /* network order */ + rc = put_entry(nodebuf, sizeof(u32), 8, fp); + if (rc) + return rc; + rc = context_write(p, &c->context[0], fp); + if (rc) + return rc; + break; + case OCON_IBPKEY: + /* subnet_prefix is in CPU order */ + prefixbuf[0] = + cpu_to_be64(c->u.ibpkey.subnet_prefix); + + rc = put_entry(prefixbuf, sizeof(u64), 1, fp); + if (rc) + return rc; + + buf[0] = cpu_to_le32(c->u.ibpkey.low_pkey); + buf[1] = cpu_to_le32(c->u.ibpkey.high_pkey); + + rc = put_entry(buf, sizeof(u32), 2, fp); + if (rc) + return rc; + rc = context_write(p, &c->context[0], fp); + if (rc) + return rc; + break; + case OCON_IBENDPORT: + len = strlen(c->u.ibendport.dev_name); + buf[0] = cpu_to_le32(len); + buf[1] = cpu_to_le32(c->u.ibendport.port); + rc = put_entry(buf, sizeof(u32), 2, fp); + if (rc) + return rc; + rc = put_entry(c->u.ibendport.dev_name, 1, len, + fp); + if (rc) + return rc; + rc = context_write(p, &c->context[0], fp); + if (rc) + return rc; + break; + } + } + } + return 0; +} + +static int genfs_write(struct policydb *p, struct policy_file *fp) +{ + struct genfs *genfs; + struct ocontext *c; + size_t len; + __le32 buf[1]; + int rc; + + len = 0; + for (genfs = p->genfs; genfs; genfs = genfs->next) + len++; + buf[0] = cpu_to_le32(len); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + for (genfs = p->genfs; genfs; genfs = genfs->next) { + len = strlen(genfs->fstype); + buf[0] = cpu_to_le32(len); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + rc = put_entry(genfs->fstype, 1, len, fp); + if (rc) + return rc; + len = 0; + for (c = genfs->head; c; c = c->next) + len++; + buf[0] = cpu_to_le32(len); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + for (c = genfs->head; c; c = c->next) { + len = strlen(c->u.name); + buf[0] = cpu_to_le32(len); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + rc = put_entry(c->u.name, 1, len, fp); + if (rc) + return rc; + buf[0] = cpu_to_le32(c->v.sclass); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + rc = context_write(p, &c->context[0], fp); + if (rc) + return rc; + } + } + return 0; +} + +static int range_write_helper(void *key, void *data, void *ptr) +{ + __le32 buf[2]; + struct range_trans *rt = key; + struct mls_range *r = data; + struct policy_data *pd = ptr; + struct policy_file *fp = pd->fp; + struct policydb *p = pd->p; + int rc; + + buf[0] = cpu_to_le32(rt->source_type); + buf[1] = cpu_to_le32(rt->target_type); + rc = put_entry(buf, sizeof(u32), 2, fp); + if (rc) + return rc; + if (p->policyvers >= POLICYDB_VERSION_RANGETRANS) { + buf[0] = cpu_to_le32(rt->target_class); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + } + rc = mls_write_range_helper(r, fp); + if (rc) + return rc; + + return 0; +} + +static int range_write(struct policydb *p, struct policy_file *fp) +{ + __le32 buf[1]; + int rc; + struct policy_data pd; + + pd.p = p; + pd.fp = fp; + + buf[0] = cpu_to_le32(p->range_tr.nel); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + + /* actually write all of the entries */ + rc = hashtab_map(&p->range_tr, range_write_helper, &pd); + if (rc) + return rc; + + return 0; +} + +static int filename_write_helper_compat(void *key, void *data, void *ptr) +{ + struct filename_trans_key *ft = key; + struct filename_trans_datum *datum = data; + struct ebitmap_node *node; + struct policy_file *fp = ptr; + __le32 buf[4]; + int rc; + u32 bit, len = strlen(ft->name); + + do { + ebitmap_for_each_positive_bit(&datum->stypes, node, bit) + { + buf[0] = cpu_to_le32(len); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + + rc = put_entry(ft->name, sizeof(char), len, fp); + if (rc) + return rc; + + buf[0] = cpu_to_le32(bit + 1); + buf[1] = cpu_to_le32(ft->ttype); + buf[2] = cpu_to_le32(ft->tclass); + buf[3] = cpu_to_le32(datum->otype); + + rc = put_entry(buf, sizeof(u32), 4, fp); + if (rc) + return rc; + } + + datum = datum->next; + } while (unlikely(datum)); + + return 0; +} + +static int filename_write_helper(void *key, void *data, void *ptr) +{ + struct filename_trans_key *ft = key; + struct filename_trans_datum *datum; + struct policy_file *fp = ptr; + __le32 buf[3]; + int rc; + u32 ndatum, len = strlen(ft->name); + + buf[0] = cpu_to_le32(len); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + + rc = put_entry(ft->name, sizeof(char), len, fp); + if (rc) + return rc; + + ndatum = 0; + datum = data; + do { + ndatum++; + datum = datum->next; + } while (unlikely(datum)); + + buf[0] = cpu_to_le32(ft->ttype); + buf[1] = cpu_to_le32(ft->tclass); + buf[2] = cpu_to_le32(ndatum); + rc = put_entry(buf, sizeof(u32), 3, fp); + if (rc) + return rc; + + datum = data; + do { + rc = ebitmap_write(&datum->stypes, fp); + if (rc) + return rc; + + buf[0] = cpu_to_le32(datum->otype); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + + datum = datum->next; + } while (unlikely(datum)); + + return 0; +} + +static int filename_trans_write(struct policydb *p, struct policy_file *fp) +{ + __le32 buf[1]; + int rc; + + if (p->policyvers < POLICYDB_VERSION_FILENAME_TRANS) + return 0; + + if (p->policyvers < POLICYDB_VERSION_COMP_FTRANS) { + buf[0] = cpu_to_le32(p->compat_filename_trans_count); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + + rc = hashtab_map(&p->filename_trans, + filename_write_helper_compat, fp); + } else { + buf[0] = cpu_to_le32(p->filename_trans.nel); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + + rc = hashtab_map(&p->filename_trans, filename_write_helper, fp); + } + return rc; +} + +/* + * Write the configuration data in a policy database + * structure to a policy database binary representation + * file. + */ +int policydb_write(struct policydb *p, struct policy_file *fp) +{ + unsigned int num_syms; + int rc; + __le32 buf[4]; + u32 config, i; + size_t len; + const struct policydb_compat_info *info; + + /* + * refuse to write policy older than compressed avtab + * to simplify the writer. There are other tests dropped + * since we assume this throughout the writer code. Be + * careful if you ever try to remove this restriction + */ + if (p->policyvers < POLICYDB_VERSION_AVTAB) { + pr_err("SELinux: refusing to write policy version %d." + " Because it is less than version %d\n", + p->policyvers, POLICYDB_VERSION_AVTAB); + return -EINVAL; + } + + config = 0; + if (p->mls_enabled) + config |= POLICYDB_CONFIG_MLS; + + if (p->reject_unknown) + config |= REJECT_UNKNOWN; + if (p->allow_unknown) + config |= ALLOW_UNKNOWN; + + /* Write the magic number and string identifiers. */ + buf[0] = cpu_to_le32(POLICYDB_MAGIC); + len = strlen(POLICYDB_STRING); + buf[1] = cpu_to_le32(len); + rc = put_entry(buf, sizeof(u32), 2, fp); + if (rc) + return rc; + rc = put_entry(POLICYDB_STRING, 1, len, fp); + if (rc) + return rc; + + /* Write the version, config, and table sizes. */ + info = policydb_lookup_compat(p->policyvers); + if (!info) { + pr_err("SELinux: compatibility lookup failed for policy " + "version %d\n", + p->policyvers); + return -EINVAL; + } + + buf[0] = cpu_to_le32(p->policyvers); + buf[1] = cpu_to_le32(config); + buf[2] = cpu_to_le32(info->sym_num); + buf[3] = cpu_to_le32(info->ocon_num); + + rc = put_entry(buf, sizeof(u32), 4, fp); + if (rc) + return rc; + + if (p->policyvers >= POLICYDB_VERSION_POLCAP) { + rc = ebitmap_write(&p->policycaps, fp); + if (rc) + return rc; + } + + if (p->policyvers >= POLICYDB_VERSION_PERMISSIVE) { + rc = ebitmap_write(&p->permissive_map, fp); + if (rc) + return rc; + } + + if (p->policyvers >= POLICYDB_VERSION_NEVERAUDIT) { + rc = ebitmap_write(&p->neveraudit_map, fp); + if (rc) + return rc; + } + + num_syms = info->sym_num; + for (i = 0; i < num_syms; i++) { + struct policy_data pd; + + pd.fp = fp; + pd.p = p; + + buf[0] = cpu_to_le32(p->symtab[i].nprim); + buf[1] = cpu_to_le32(p->symtab[i].table.nel); + + rc = put_entry(buf, sizeof(u32), 2, fp); + if (rc) + return rc; + rc = hashtab_map(&p->symtab[i].table, write_f[i], &pd); + if (rc) + return rc; + } + + rc = avtab_write(p, &p->te_avtab, fp); + if (rc) + return rc; + + rc = cond_write_list(p, fp); + if (rc) + return rc; + + rc = role_trans_write(p, fp); + if (rc) + return rc; + + rc = role_allow_write(p->role_allow, fp); + if (rc) + return rc; + + rc = filename_trans_write(p, fp); + if (rc) + return rc; + + rc = ocontext_write(p, info, fp); + if (rc) + return rc; + + rc = genfs_write(p, fp); + if (rc) + return rc; + + rc = range_write(p, fp); + if (rc) + return rc; + + for (i = 0; i < p->p_types.nprim; i++) { + struct ebitmap *e = &p->type_attr_map_array[i]; + + rc = ebitmap_write(e, fp); + if (rc) + return rc; + } + + return 0; +} diff --git a/security/selinux/ss/policydb.h b/security/selinux/ss/policydb.h new file mode 100644 index 000000000..974180b2e --- /dev/null +++ b/security/selinux/ss/policydb.h @@ -0,0 +1,428 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * A policy database (policydb) specifies the + * configuration data for the security policy. + * + * Author : Stephen Smalley, <stephen.smalley.work@gmail.com> + */ + +/* + * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com> + * Support for enhanced MLS infrastructure. + * Copyright (C) 2004-2005 Trusted Computer Solutions, Inc. + * + * Updated: Frank Mayer <mayerf@tresys.com> and + * Karl MacMillan <kmacmillan@tresys.com> + * Added conditional policy language extensions + * Copyright (C) 2003-2004 Tresys Technology, LLC + */ + +#ifndef _SS_POLICYDB_H_ +#define _SS_POLICYDB_H_ + +#include "symtab.h" +#include "avtab.h" +#include "sidtab.h" +#include "ebitmap.h" +#include "mls_types.h" +#include "context.h" +#include "constraint.h" + +/* + * A datum type is defined for each kind of symbol + * in the configuration data: individual permissions, + * common prefixes for access vectors, classes, + * users, roles, types, sensitivities, categories, etc. + */ + +/* Permission attributes */ +struct perm_datum { + u32 value; /* permission bit + 1 */ +}; + +/* Attributes of a common prefix for access vectors */ +struct common_datum { + u32 value; /* internal common value */ + struct symtab permissions; /* common permissions */ +}; + +/* Class attributes */ +struct class_datum { + u16 value; /* class value */ + char *comkey; /* common name */ + struct common_datum *comdatum; /* common datum */ + struct symtab permissions; /* class-specific permission symbol table */ + struct constraint_node *constraints; /* constraints on class perms */ + struct constraint_node *validatetrans; /* special transition rules */ +/* Options how a new object user, role, and type should be decided */ +#define DEFAULT_SOURCE 1 +#define DEFAULT_TARGET 2 + char default_user; + char default_role; + char default_type; +/* Options how a new object range should be decided */ +#define DEFAULT_SOURCE_LOW 1 +#define DEFAULT_SOURCE_HIGH 2 +#define DEFAULT_SOURCE_LOW_HIGH 3 +#define DEFAULT_TARGET_LOW 4 +#define DEFAULT_TARGET_HIGH 5 +#define DEFAULT_TARGET_LOW_HIGH 6 +#define DEFAULT_GLBLUB 7 + char default_range; +}; + +/* Role attributes */ +struct role_datum { + u32 value; /* internal role value */ + u32 bounds; /* boundary of role, 0 for none */ + struct ebitmap dominates; /* set of roles dominated by this role */ + struct ebitmap types; /* set of authorized types for role */ +}; + +struct role_trans_key { + u32 role; /* current role */ + u32 type; /* program executable type, or new object type */ + u16 tclass; /* process class, or new object class */ +}; + +struct role_trans_datum { + u32 new_role; /* new role */ +}; + +struct filename_trans_key { + u32 ttype; /* parent dir context */ + u16 tclass; /* class of new object */ + const char *name; /* last path component */ +}; + +struct filename_trans_datum { + struct ebitmap stypes; /* bitmap of source types for this otype */ + u32 otype; /* resulting type of new object */ + struct filename_trans_datum *next; /* record for next otype*/ +}; + +struct role_allow { + u32 role; /* current role */ + u32 new_role; /* new role */ + struct role_allow *next; +}; + +/* Type attributes */ +struct type_datum { + u32 value; /* internal type value */ + u32 bounds; /* boundary of type, 0 for none */ + /* internally unused, only forwarded via policydb_write() */ + unsigned char primary; /* primary name? */ + unsigned char attribute; /* attribute ?*/ +}; + +/* User attributes */ +struct user_datum { + u32 value; /* internal user value */ + u32 bounds; /* bounds of user, 0 for none */ + struct ebitmap roles; /* set of authorized roles for user */ + struct mls_range range; /* MLS range (min - max) for user */ + struct mls_level dfltlevel; /* default login MLS level for user */ +}; + +/* Sensitivity attributes */ +struct level_datum { + struct mls_level level; /* sensitivity and associated categories */ + unsigned char isalias; /* is this sensitivity an alias for another? */ +}; + +/* Category attributes */ +struct cat_datum { + u32 value; /* internal category bit + 1 */ + unsigned char isalias; /* is this category an alias for another? */ +}; + +struct range_trans { + u32 source_type; + u32 target_type; + u16 target_class; +}; + +/* Boolean data type */ +struct cond_bool_datum { + u32 value; /* internal type value */ + int state; +}; + +struct cond_node; + +/* + * type set preserves data needed to determine constraint info from + * policy source. This is not used by the kernel policy but allows + * utilities such as audit2allow to determine constraint denials. + */ +struct type_set { + struct ebitmap types; + struct ebitmap negset; + u32 flags; +}; + +/* + * The configuration data includes security contexts for + * initial SIDs, unlabeled file systems, TCP and UDP port numbers, + * network interfaces, and nodes. This structure stores the + * relevant data for one such entry. Entries of the same kind + * (e.g. all initial SIDs) are linked together into a list. + */ +struct ocontext { + union { + char *name; /* name of initial SID, fs, netif, fstype, path */ + struct { + u8 protocol; + u16 low_port; + u16 high_port; + } port; /* TCP or UDP port information */ + struct { + u32 addr; + u32 mask; + } node; /* node information */ + struct { + u32 addr[4]; + u32 mask[4]; + } node6; /* IPv6 node information */ + struct { + u64 subnet_prefix; + u16 low_pkey; + u16 high_pkey; + } ibpkey; + struct { + char *dev_name; + u8 port; + } ibendport; + } u; + union { + u16 sclass; /* security class for genfs (can be 0 for wildcard) */ + u32 behavior; /* labeling behavior for fs_use */ + } v; + struct context context[2]; /* security context(s) */ + u32 sid[2]; /* SID(s) */ + struct ocontext *next; +}; + +struct genfs { + char *fstype; + struct ocontext *head; + struct genfs *next; +}; + +/* symbol table array indices */ +#define SYM_COMMONS 0 +#define SYM_CLASSES 1 +#define SYM_ROLES 2 +#define SYM_TYPES 3 +#define SYM_USERS 4 +#define SYM_BOOLS 5 +#define SYM_LEVELS 6 +#define SYM_CATS 7 +#define SYM_NUM 8 + +/* object context array indices */ +#define OCON_ISID 0 /* initial SIDs */ +#define OCON_FS 1 /* unlabeled file systems (deprecated) */ +#define OCON_PORT 2 /* TCP and UDP port numbers */ +#define OCON_NETIF 3 /* network interfaces */ +#define OCON_NODE 4 /* nodes */ +#define OCON_FSUSE 5 /* fs_use */ +#define OCON_NODE6 6 /* IPv6 nodes */ +#define OCON_IBPKEY 7 /* Infiniband PKeys */ +#define OCON_IBENDPORT 8 /* Infiniband end ports */ +#define OCON_NUM 9 + +/* The policy database */ +struct policydb { + int mls_enabled; + + /* symbol tables */ + struct symtab symtab[SYM_NUM]; +#define p_commons symtab[SYM_COMMONS] +#define p_classes symtab[SYM_CLASSES] +#define p_roles symtab[SYM_ROLES] +#define p_types symtab[SYM_TYPES] +#define p_users symtab[SYM_USERS] +#define p_bools symtab[SYM_BOOLS] +#define p_levels symtab[SYM_LEVELS] +#define p_cats symtab[SYM_CATS] + + /* symbol names indexed by (value - 1) */ + char **sym_val_to_name[SYM_NUM]; + + /* class, role, and user attributes indexed by (value - 1) */ + struct class_datum **class_val_to_struct; + struct role_datum **role_val_to_struct; + struct user_datum **user_val_to_struct; + struct type_datum **type_val_to_struct; + + /* type enforcement access vectors and transitions */ + struct avtab te_avtab; + + /* role transitions */ + struct hashtab role_tr; + + /* file transitions with the last path component */ + /* quickly exclude lookups when parent ttype has no rules */ + struct ebitmap filename_trans_ttypes; + /* actual set of filename_trans rules */ + struct hashtab filename_trans; + /* only used if policyvers < POLICYDB_VERSION_COMP_FTRANS */ + u32 compat_filename_trans_count; + + /* bools indexed by (value - 1) */ + struct cond_bool_datum **bool_val_to_struct; + /* type enforcement conditional access vectors and transitions */ + struct avtab te_cond_avtab; + /* array indexing te_cond_avtab by conditional */ + struct cond_node *cond_list; + u32 cond_list_len; + + /* role allows */ + struct role_allow *role_allow; + + /* security contexts of initial SIDs, unlabeled file systems, + TCP or UDP port numbers, network interfaces and nodes */ + struct ocontext *ocontexts[OCON_NUM]; + + /* security contexts for files in filesystems that cannot support + a persistent label mapping or use another + fixed labeling behavior. */ + struct genfs *genfs; + + /* range transitions table (range_trans_key -> mls_range) */ + struct hashtab range_tr; + + /* type -> attribute reverse mapping */ + struct ebitmap *type_attr_map_array; + + struct ebitmap policycaps; + + struct ebitmap permissive_map; + + struct ebitmap neveraudit_map; + + /* length of this policy when it was loaded */ + size_t len; + + unsigned int policyvers; + + unsigned int reject_unknown : 1; + unsigned int allow_unknown : 1; + + u16 process_class; + u32 process_trans_perms; +} __randomize_layout; + +struct policy_file { + char *data; + size_t len; +}; + +extern void policydb_destroy(struct policydb *p); +extern int policydb_load_isids(struct policydb *p, struct sidtab *s); +extern bool policydb_context_isvalid(const struct policydb *p, + const struct context *c); +extern bool policydb_class_isvalid(const struct policydb *p, u16 class); +extern bool policydb_type_isvalid(const struct policydb *p, u32 type); +extern bool policydb_simpletype_isvalid(const struct policydb *p, u32 type); +extern bool policydb_role_isvalid(const struct policydb *p, u32 role); +extern bool policydb_user_isvalid(const struct policydb *p, u32 user); +extern int policydb_read(struct policydb *p, struct policy_file *fp); +extern int policydb_write(struct policydb *p, struct policy_file *fp); + +extern struct filename_trans_datum * +policydb_filenametr_search(struct policydb *p, struct filename_trans_key *key); + +extern struct mls_range *policydb_rangetr_search(struct policydb *p, + struct range_trans *key); + +extern struct role_trans_datum * +policydb_roletr_search(struct policydb *p, struct role_trans_key *key); + +#define POLICYDB_CONFIG_MLS 1 + +/* the config flags related to unknown classes/perms are bits 2 and 3 */ +#define REJECT_UNKNOWN 0x00000002 +#define ALLOW_UNKNOWN 0x00000004 + +#define OBJECT_R "object_r" +#define OBJECT_R_VAL 1 + +#define POLICYDB_MAGIC SELINUX_MAGIC +#define POLICYDB_STRING "SE Linux" + +struct policy_data { + struct policydb *p; + struct policy_file *fp; +}; + +static inline int size_check(size_t bytes, size_t num, + const struct policy_file *fp) +{ + size_t len; + + if (unlikely(check_mul_overflow(bytes, num, &len))) + return -EINVAL; + + if (unlikely(len > fp->len)) + return -EINVAL; + + return 0; +} + +static inline int next_entry(void *buf, struct policy_file *fp, size_t bytes) +{ + if (bytes > fp->len) + return -EINVAL; + + memcpy(buf, fp->data, bytes); + fp->data += bytes; + fp->len -= bytes; + return 0; +} + +static inline int put_entry(const void *buf, size_t bytes, size_t num, + struct policy_file *fp) +{ + size_t len; + + if (unlikely(check_mul_overflow(bytes, num, &len))) + return -EINVAL; + + if (len > fp->len) + return -EINVAL; + memcpy(fp->data, buf, len); + fp->data += len; + fp->len -= len; + + return 0; +} + +static inline const char *sym_name(const struct policydb *p, unsigned int sym_num, + unsigned int element_nr) +{ + return p->sym_val_to_name[sym_num][element_nr]; +} + +static inline bool val_is_boolean(u32 value) +{ + return value == 0 || value == 1; +} + +extern int str_read(char **strp, gfp_t flags, struct policy_file *fp, u32 len); + +extern u16 string_to_security_class(struct policydb *p, const char *name); +extern u32 string_to_av_perm(struct policydb *p, u16 tclass, const char *name); + +#define pr_warn_once_policyload(policy, fmt, ...) \ + do { \ + static const void *prev_policy__; \ + if (prev_policy__ != policy) { \ + pr_warn(fmt, ##__VA_ARGS__); \ + prev_policy__ = policy; \ + } \ + } while (0) + +#endif /* _SS_POLICYDB_H_ */ diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c new file mode 100644 index 000000000..da77ad769 --- /dev/null +++ b/security/selinux/ss/services.c @@ -0,0 +1,3962 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Implementation of the security services. + * + * Authors : Stephen Smalley, <stephen.smalley.work@gmail.com> + * James Morris <jmorris@redhat.com> + * + * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com> + * + * Support for enhanced MLS infrastructure. + * Support for context based audit filters. + * + * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com> + * + * Added conditional policy language extensions + * + * Updated: Hewlett-Packard <paul@paul-moore.com> + * + * Added support for NetLabel + * Added support for the policy capability bitmap + * + * Updated: Chad Sellers <csellers@tresys.com> + * + * Added validation of kernel classes and permissions + * + * Updated: KaiGai Kohei <kaigai@ak.jp.nec.com> + * + * Added support for bounds domain and audit messaged on masked permissions + * + * Updated: Guido Trentalancia <guido@trentalancia.com> + * + * Added support for runtime switching of the policy type + * + * Copyright (C) 2008, 2009 NEC Corporation + * Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P. + * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc. + * Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC + * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com> + */ +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/string.h> +#include <linux/spinlock.h> +#include <linux/rcupdate.h> +#include <linux/errno.h> +#include <linux/in.h> +#include <linux/sched.h> +#include <linux/audit.h> +#include <linux/parser.h> +#include <linux/vmalloc.h> +#include <linux/lsm_hooks.h> +#include <net/netlabel.h> + +#include "flask.h" +#include "avc.h" +#include "avc_ss.h" +#include "security.h" +#include "context.h" +#include "policydb.h" +#include "sidtab.h" +#include "services.h" +#include "conditional.h" +#include "mls.h" +#include "objsec.h" +#include "netlabel.h" +#include "xfrm.h" +#include "ebitmap.h" +#include "audit.h" +#include "policycap_names.h" +#include "ima.h" + +struct selinux_policy_convert_data { + struct convert_context_args args; + struct sidtab_convert_params sidtab_params; +}; + +/* Forward declaration. */ +static int context_struct_to_string(struct policydb *policydb, + struct context *context, + char **scontext, + u32 *scontext_len); + +static int sidtab_entry_to_string(struct policydb *policydb, + struct sidtab *sidtab, + struct sidtab_entry *entry, + char **scontext, + u32 *scontext_len); + +static void context_struct_compute_av(struct policydb *policydb, + struct context *scontext, + struct context *tcontext, + u16 tclass, + struct av_decision *avd, + struct extended_perms *xperms); + +static int selinux_set_mapping(struct policydb *pol, + const struct security_class_mapping *map, + struct selinux_map *out_map) +{ + u16 i, j; + bool print_unknown_handle = false; + + /* Find number of classes in the input mapping */ + if (!map) + return -EINVAL; + i = 0; + while (map[i].name) + i++; + + /* Allocate space for the class records, plus one for class zero */ + out_map->mapping = kzalloc_objs(*out_map->mapping, ++i, GFP_ATOMIC); + if (!out_map->mapping) + return -ENOMEM; + + /* Store the raw class and permission values */ + j = 0; + while (map[j].name) { + const struct security_class_mapping *p_in = map + (j++); + struct selinux_mapping *p_out = out_map->mapping + j; + u16 k; + + /* An empty class string skips ahead */ + if (!strcmp(p_in->name, "")) { + p_out->num_perms = 0; + continue; + } + + p_out->value = string_to_security_class(pol, p_in->name); + if (!p_out->value) { + pr_info("SELinux: Class %s not defined in policy.\n", + p_in->name); + if (pol->reject_unknown) + goto err; + p_out->num_perms = 0; + print_unknown_handle = true; + continue; + } + + k = 0; + while (p_in->perms[k]) { + /* An empty permission string skips ahead */ + if (!*p_in->perms[k]) { + k++; + continue; + } + p_out->perms[k] = string_to_av_perm(pol, p_out->value, + p_in->perms[k]); + if (!p_out->perms[k]) { + pr_info("SELinux: Permission %s in class %s not defined in policy.\n", + p_in->perms[k], p_in->name); + if (pol->reject_unknown) + goto err; + print_unknown_handle = true; + } + + k++; + } + p_out->num_perms = k; + } + + if (print_unknown_handle) + pr_info("SELinux: the above unknown classes and permissions will be %s\n", + pol->allow_unknown ? "allowed" : "denied"); + + out_map->size = i; + return 0; +err: + kfree(out_map->mapping); + out_map->mapping = NULL; + return -EINVAL; +} + +/* + * Get real, policy values from mapped values + */ + +static u16 unmap_class(struct selinux_map *map, u16 tclass) +{ + if (tclass < map->size) + return map->mapping[tclass].value; + + return tclass; +} + +/* + * Get kernel value for class from its policy value + */ +static u16 map_class(struct selinux_map *map, u16 pol_value) +{ + u16 i; + + for (i = 1; i < map->size; i++) { + if (map->mapping[i].value == pol_value) + return i; + } + + return SECCLASS_NULL; +} + +static void map_decision(struct selinux_map *map, + u16 tclass, struct av_decision *avd, + int allow_unknown) +{ + if (tclass < map->size) { + struct selinux_mapping *mapping = &map->mapping[tclass]; + unsigned int i, n = mapping->num_perms; + u32 result; + + for (i = 0, result = 0; i < n; i++) { + if (avd->allowed & mapping->perms[i]) + result |= (u32)1<<i; + if (allow_unknown && !mapping->perms[i]) + result |= (u32)1<<i; + } + avd->allowed = result; + + for (i = 0, result = 0; i < n; i++) + if (avd->auditallow & mapping->perms[i]) + result |= (u32)1<<i; + avd->auditallow = result; + + for (i = 0, result = 0; i < n; i++) { + if (avd->auditdeny & mapping->perms[i]) + result |= (u32)1<<i; + if (!allow_unknown && !mapping->perms[i]) + result |= (u32)1<<i; + } + /* + * In case the kernel has a bug and requests a permission + * between num_perms and the maximum permission number, we + * should audit that denial + */ + for (; i < (sizeof(u32)*8); i++) + result |= (u32)1<<i; + avd->auditdeny = result; + } +} + +int security_mls_enabled(void) +{ + int mls_enabled; + struct selinux_policy *policy; + + if (!selinux_initialized()) + return 0; + + rcu_read_lock(); + policy = rcu_dereference(selinux_state.policy); + mls_enabled = policy->policydb.mls_enabled; + rcu_read_unlock(); + return mls_enabled; +} + +/* + * Return the boolean value of a constraint expression + * when it is applied to the specified source and target + * security contexts. + * + * xcontext is a special beast... It is used by the validatetrans rules + * only. For these rules, scontext is the context before the transition, + * tcontext is the context after the transition, and xcontext is the context + * of the process performing the transition. All other callers of + * constraint_expr_eval should pass in NULL for xcontext. + */ +static int constraint_expr_eval(struct policydb *policydb, + struct context *scontext, + struct context *tcontext, + struct context *xcontext, + struct constraint_expr *cexpr) +{ + u32 val1, val2; + struct context *c; + struct role_datum *r1, *r2; + struct mls_level *l1, *l2; + struct constraint_expr *e; + int s[CEXPR_MAXDEPTH]; + int sp = -1; + + for (e = cexpr; e; e = e->next) { + switch (e->expr_type) { + case CEXPR_NOT: + BUG_ON(sp < 0); + s[sp] = !s[sp]; + break; + case CEXPR_AND: + BUG_ON(sp < 1); + sp--; + s[sp] &= s[sp + 1]; + break; + case CEXPR_OR: + BUG_ON(sp < 1); + sp--; + s[sp] |= s[sp + 1]; + break; + case CEXPR_ATTR: + if (sp == (CEXPR_MAXDEPTH - 1)) + return 0; + switch (e->attr) { + case CEXPR_USER: + val1 = scontext->user; + val2 = tcontext->user; + break; + case CEXPR_TYPE: + val1 = scontext->type; + val2 = tcontext->type; + break; + case CEXPR_ROLE: + val1 = scontext->role; + val2 = tcontext->role; + r1 = policydb->role_val_to_struct[val1 - 1]; + r2 = policydb->role_val_to_struct[val2 - 1]; + switch (e->op) { + case CEXPR_DOM: + s[++sp] = ebitmap_get_bit(&r1->dominates, + val2 - 1); + continue; + case CEXPR_DOMBY: + s[++sp] = ebitmap_get_bit(&r2->dominates, + val1 - 1); + continue; + case CEXPR_INCOMP: + s[++sp] = (!ebitmap_get_bit(&r1->dominates, + val2 - 1) && + !ebitmap_get_bit(&r2->dominates, + val1 - 1)); + continue; + default: + break; + } + break; + case CEXPR_L1L2: + l1 = &(scontext->range.level[0]); + l2 = &(tcontext->range.level[0]); + goto mls_ops; + case CEXPR_L1H2: + l1 = &(scontext->range.level[0]); + l2 = &(tcontext->range.level[1]); + goto mls_ops; + case CEXPR_H1L2: + l1 = &(scontext->range.level[1]); + l2 = &(tcontext->range.level[0]); + goto mls_ops; + case CEXPR_H1H2: + l1 = &(scontext->range.level[1]); + l2 = &(tcontext->range.level[1]); + goto mls_ops; + case CEXPR_L1H1: + l1 = &(scontext->range.level[0]); + l2 = &(scontext->range.level[1]); + goto mls_ops; + case CEXPR_L2H2: + l1 = &(tcontext->range.level[0]); + l2 = &(tcontext->range.level[1]); + goto mls_ops; +mls_ops: + switch (e->op) { + case CEXPR_EQ: + s[++sp] = mls_level_eq(l1, l2); + continue; + case CEXPR_NEQ: + s[++sp] = !mls_level_eq(l1, l2); + continue; + case CEXPR_DOM: + s[++sp] = mls_level_dom(l1, l2); + continue; + case CEXPR_DOMBY: + s[++sp] = mls_level_dom(l2, l1); + continue; + case CEXPR_INCOMP: + s[++sp] = mls_level_incomp(l2, l1); + continue; + default: + BUG(); + return 0; + } + break; + default: + BUG(); + return 0; + } + + switch (e->op) { + case CEXPR_EQ: + s[++sp] = (val1 == val2); + break; + case CEXPR_NEQ: + s[++sp] = (val1 != val2); + break; + default: + BUG(); + return 0; + } + break; + case CEXPR_NAMES: + if (sp == (CEXPR_MAXDEPTH-1)) + return 0; + c = scontext; + if (e->attr & CEXPR_TARGET) + c = tcontext; + else if (e->attr & CEXPR_XTARGET) { + c = xcontext; + if (!c) { + BUG(); + return 0; + } + } + if (e->attr & CEXPR_USER) + val1 = c->user; + else if (e->attr & CEXPR_ROLE) + val1 = c->role; + else if (e->attr & CEXPR_TYPE) + val1 = c->type; + else { + BUG(); + return 0; + } + + switch (e->op) { + case CEXPR_EQ: + s[++sp] = ebitmap_get_bit(&e->names, val1 - 1); + break; + case CEXPR_NEQ: + s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1); + break; + default: + BUG(); + return 0; + } + break; + default: + BUG(); + return 0; + } + } + + BUG_ON(sp != 0); + return s[0]; +} + +/* + * security_dump_masked_av - dumps masked permissions during + * security_compute_av due to RBAC, MLS/Constraint and Type bounds. + */ +static int dump_masked_av_helper(void *k, void *d, void *args) +{ + struct perm_datum *pdatum = d; + char **permission_names = args; + + permission_names[pdatum->value - 1] = (char *)k; + + return 0; +} + +static void security_dump_masked_av(struct policydb *policydb, + struct context *scontext, + struct context *tcontext, + u16 tclass, + u32 permissions, + const char *reason) +{ + struct common_datum *common_dat; + struct class_datum *tclass_dat; + struct audit_buffer *ab; + const char *tclass_name; + char *scontext_name = NULL; + char *tcontext_name = NULL; + char *permission_names[SEL_VEC_MAX]; + int index; + u32 length; + bool need_comma = false; + + if (!permissions) + return; + + tclass_name = sym_name(policydb, SYM_CLASSES, tclass - 1); + tclass_dat = policydb->class_val_to_struct[tclass - 1]; + common_dat = tclass_dat->comdatum; + + /* init permission_names */ + if (common_dat && + hashtab_map(&common_dat->permissions.table, + dump_masked_av_helper, permission_names) < 0) + goto out; + + if (hashtab_map(&tclass_dat->permissions.table, + dump_masked_av_helper, permission_names) < 0) + goto out; + + /* get scontext/tcontext in text form */ + if (context_struct_to_string(policydb, scontext, + &scontext_name, &length) < 0) + goto out; + + if (context_struct_to_string(policydb, tcontext, + &tcontext_name, &length) < 0) + goto out; + + /* audit a message */ + ab = audit_log_start(audit_context(), + GFP_ATOMIC, AUDIT_SELINUX_ERR); + if (!ab) + goto out; + + audit_log_format(ab, "op=security_compute_av reason=%s " + "scontext=%s tcontext=%s tclass=%s perms=", + reason, scontext_name, tcontext_name, tclass_name); + + for (index = 0; index < SEL_VEC_MAX; index++) { + u32 mask = (1 << index); + + if ((mask & permissions) == 0) + continue; + + audit_log_format(ab, "%s%s", + need_comma ? "," : "", + permission_names[index] + ? permission_names[index] : "????"); + need_comma = true; + } + audit_log_end(ab); +out: + /* release scontext/tcontext */ + kfree(tcontext_name); + kfree(scontext_name); +} + +/* + * security_boundary_permission - drops violated permissions + * on boundary constraint. + */ +static void type_attribute_bounds_av(struct policydb *policydb, + struct context *scontext, + struct context *tcontext, + u16 tclass, + struct av_decision *avd) +{ + struct context lo_scontext; + struct context lo_tcontext, *tcontextp = tcontext; + struct av_decision lo_avd; + struct type_datum *source; + struct type_datum *target; + u32 masked = 0; + + source = policydb->type_val_to_struct[scontext->type - 1]; + BUG_ON(!source); + + if (!source->bounds) + return; + + target = policydb->type_val_to_struct[tcontext->type - 1]; + BUG_ON(!target); + + memset(&lo_avd, 0, sizeof(lo_avd)); + + memcpy(&lo_scontext, scontext, sizeof(lo_scontext)); + lo_scontext.type = source->bounds; + + if (target->bounds) { + memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext)); + lo_tcontext.type = target->bounds; + tcontextp = &lo_tcontext; + } + + context_struct_compute_av(policydb, &lo_scontext, + tcontextp, + tclass, + &lo_avd, + NULL); + + masked = ~lo_avd.allowed & avd->allowed; + + if (likely(!masked)) + return; /* no masked permission */ + + /* mask violated permissions */ + avd->allowed &= ~masked; + + /* audit masked permissions */ + security_dump_masked_av(policydb, scontext, tcontext, + tclass, masked, "bounds"); +} + +/* + * Flag which drivers have permissions and which base permissions are covered. + */ +void services_compute_xperms_drivers( + struct extended_perms *xperms, + struct avtab_node *node) +{ + unsigned int i; + + switch (node->datum.u.xperms->specified) { + case AVTAB_XPERMS_IOCTLDRIVER: + xperms->base_perms |= AVC_EXT_IOCTL; + /* if one or more driver has all permissions allowed */ + for (i = 0; i < ARRAY_SIZE(xperms->drivers.p); i++) + xperms->drivers.p[i] |= node->datum.u.xperms->perms.p[i]; + break; + case AVTAB_XPERMS_IOCTLFUNCTION: + xperms->base_perms |= AVC_EXT_IOCTL; + /* if allowing permissions within a driver */ + security_xperm_set(xperms->drivers.p, + node->datum.u.xperms->driver); + break; + case AVTAB_XPERMS_NLMSG: + xperms->base_perms |= AVC_EXT_NLMSG; + /* if allowing permissions within a driver */ + security_xperm_set(xperms->drivers.p, + node->datum.u.xperms->driver); + break; + } + + xperms->len = 1; +} + +/* + * Compute access vectors and extended permissions based on a context + * structure pair for the permissions in a particular class. + */ +static void context_struct_compute_av(struct policydb *policydb, + struct context *scontext, + struct context *tcontext, + u16 tclass, + struct av_decision *avd, + struct extended_perms *xperms) +{ + struct constraint_node *constraint; + struct role_allow *ra; + struct avtab_key avkey; + struct avtab_node *node; + struct class_datum *tclass_datum; + struct ebitmap *sattr, *tattr; + struct ebitmap_node *snode, *tnode; + unsigned int i, j; + + avd->allowed = 0; + avd->auditallow = 0; + avd->auditdeny = 0xffffffff; + if (xperms) { + memset(xperms, 0, sizeof(*xperms)); + } + + if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) { + pr_warn_ratelimited("SELinux: Invalid class %u\n", tclass); + return; + } + + tclass_datum = policydb->class_val_to_struct[tclass - 1]; + + /* + * If a specific type enforcement rule was defined for + * this permission check, then use it. + */ + avkey.target_class = tclass; + avkey.specified = AVTAB_AV | AVTAB_XPERMS; + sattr = &policydb->type_attr_map_array[scontext->type - 1]; + tattr = &policydb->type_attr_map_array[tcontext->type - 1]; + ebitmap_for_each_positive_bit(sattr, snode, i) { + ebitmap_for_each_positive_bit(tattr, tnode, j) { + avkey.source_type = i + 1; + avkey.target_type = j + 1; + for (node = avtab_search_node(&policydb->te_avtab, + &avkey); + node; + node = avtab_search_node_next(node, avkey.specified)) { + if (node->key.specified == AVTAB_ALLOWED) + avd->allowed |= node->datum.u.data; + else if (node->key.specified == AVTAB_AUDITALLOW) + avd->auditallow |= node->datum.u.data; + else if (node->key.specified == AVTAB_AUDITDENY) + avd->auditdeny &= node->datum.u.data; + else if (xperms && (node->key.specified & AVTAB_XPERMS)) + services_compute_xperms_drivers(xperms, node); + } + + /* Check conditional av table for additional permissions */ + cond_compute_av(&policydb->te_cond_avtab, &avkey, + avd, xperms); + + } + } + + /* + * Remove any permissions prohibited by a constraint (this includes + * the MLS policy). + */ + constraint = tclass_datum->constraints; + while (constraint) { + if ((constraint->permissions & (avd->allowed)) && + !constraint_expr_eval(policydb, scontext, tcontext, NULL, + constraint->expr)) { + avd->allowed &= ~(constraint->permissions); + } + constraint = constraint->next; + } + + /* + * If checking process transition permission and the + * role is changing, then check the (current_role, new_role) + * pair. + */ + if (tclass == policydb->process_class && + (avd->allowed & policydb->process_trans_perms) && + scontext->role != tcontext->role) { + for (ra = policydb->role_allow; ra; ra = ra->next) { + if (scontext->role == ra->role && + tcontext->role == ra->new_role) + break; + } + if (!ra) + avd->allowed &= ~policydb->process_trans_perms; + } + + /* + * If the given source and target types have boundary + * constraint, lazy checks have to mask any violated + * permission and notice it to userspace via audit. + * + * Infinite recursion is avoided via a depth pre-check in + * type_bounds_sanity_check(). + */ + type_attribute_bounds_av(policydb, scontext, tcontext, + tclass, avd); +} + +static int security_validtrans_handle_fail(struct selinux_policy *policy, + struct sidtab_entry *oentry, + struct sidtab_entry *nentry, + struct sidtab_entry *tentry, + u16 tclass) +{ + struct policydb *p = &policy->policydb; + struct sidtab *sidtab = policy->sidtab; + char *o = NULL, *n = NULL, *t = NULL; + u32 olen, nlen, tlen; + + if (sidtab_entry_to_string(p, sidtab, oentry, &o, &olen)) + goto out; + if (sidtab_entry_to_string(p, sidtab, nentry, &n, &nlen)) + goto out; + if (sidtab_entry_to_string(p, sidtab, tentry, &t, &tlen)) + goto out; + audit_log(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR, + "op=security_validate_transition seresult=denied" + " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s", + o, n, t, sym_name(p, SYM_CLASSES, tclass-1)); +out: + kfree(o); + kfree(n); + kfree(t); + + if (!enforcing_enabled()) + return 0; + return -EPERM; +} + +static int security_compute_validatetrans(u32 oldsid, u32 newsid, u32 tasksid, + u16 orig_tclass, bool user) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + struct sidtab_entry *oentry; + struct sidtab_entry *nentry; + struct sidtab_entry *tentry; + struct class_datum *tclass_datum; + struct constraint_node *constraint; + u16 tclass; + int rc = 0; + + + if (!selinux_initialized()) + return 0; + + rcu_read_lock(); + + policy = rcu_dereference(selinux_state.policy); + policydb = &policy->policydb; + sidtab = policy->sidtab; + + if (!user) + tclass = unmap_class(&policy->map, orig_tclass); + else + tclass = orig_tclass; + + if (!tclass || tclass > policydb->p_classes.nprim) { + rc = -EINVAL; + goto out; + } + tclass_datum = policydb->class_val_to_struct[tclass - 1]; + + oentry = sidtab_search_entry(sidtab, oldsid); + if (!oentry) { + pr_err("SELinux: %s: unrecognized SID %d\n", + __func__, oldsid); + rc = -EINVAL; + goto out; + } + + nentry = sidtab_search_entry(sidtab, newsid); + if (!nentry) { + pr_err("SELinux: %s: unrecognized SID %d\n", + __func__, newsid); + rc = -EINVAL; + goto out; + } + + tentry = sidtab_search_entry(sidtab, tasksid); + if (!tentry) { + pr_err("SELinux: %s: unrecognized SID %d\n", + __func__, tasksid); + rc = -EINVAL; + goto out; + } + + constraint = tclass_datum->validatetrans; + while (constraint) { + if (!constraint_expr_eval(policydb, &oentry->context, + &nentry->context, &tentry->context, + constraint->expr)) { + if (user) + rc = -EPERM; + else + rc = security_validtrans_handle_fail(policy, + oentry, + nentry, + tentry, + tclass); + goto out; + } + constraint = constraint->next; + } + +out: + rcu_read_unlock(); + return rc; +} + +int security_validate_transition_user(u32 oldsid, u32 newsid, u32 tasksid, + u16 tclass) +{ + return security_compute_validatetrans(oldsid, newsid, tasksid, + tclass, true); +} + +int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid, + u16 orig_tclass) +{ + return security_compute_validatetrans(oldsid, newsid, tasksid, + orig_tclass, false); +} + +/* + * security_bounded_transition - check whether the given + * transition is directed to bounded, or not. + * It returns 0, if @newsid is bounded by @oldsid. + * Otherwise, it returns error code. + * + * @oldsid : current security identifier + * @newsid : destinated security identifier + */ +int security_bounded_transition(u32 old_sid, u32 new_sid) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + struct sidtab_entry *old_entry, *new_entry; + struct type_datum *type; + u32 index; + int rc; + + if (!selinux_initialized()) + return 0; + + rcu_read_lock(); + policy = rcu_dereference(selinux_state.policy); + policydb = &policy->policydb; + sidtab = policy->sidtab; + + rc = -EINVAL; + old_entry = sidtab_search_entry(sidtab, old_sid); + if (!old_entry) { + pr_err("SELinux: %s: unrecognized SID %u\n", + __func__, old_sid); + goto out; + } + + rc = -EINVAL; + new_entry = sidtab_search_entry(sidtab, new_sid); + if (!new_entry) { + pr_err("SELinux: %s: unrecognized SID %u\n", + __func__, new_sid); + goto out; + } + + rc = 0; + /* type/domain unchanged */ + if (old_entry->context.type == new_entry->context.type) + goto out; + + index = new_entry->context.type; + while (true) { + type = policydb->type_val_to_struct[index - 1]; + BUG_ON(!type); + + /* not bounded anymore */ + rc = -EPERM; + if (!type->bounds) + break; + + /* @newsid is bounded by @oldsid */ + rc = 0; + if (type->bounds == old_entry->context.type) + break; + + index = type->bounds; + } + + if (rc) { + char *old_name = NULL; + char *new_name = NULL; + u32 length; + + if (!sidtab_entry_to_string(policydb, sidtab, old_entry, + &old_name, &length) && + !sidtab_entry_to_string(policydb, sidtab, new_entry, + &new_name, &length)) { + audit_log(audit_context(), + GFP_ATOMIC, AUDIT_SELINUX_ERR, + "op=security_bounded_transition " + "seresult=denied " + "oldcontext=%s newcontext=%s", + old_name, new_name); + } + kfree(new_name); + kfree(old_name); + } +out: + rcu_read_unlock(); + + return rc; +} + +static void avd_init(struct selinux_policy *policy, struct av_decision *avd) +{ + avd->allowed = 0; + avd->auditallow = 0; + avd->auditdeny = 0xffffffff; + if (policy) + avd->seqno = policy->latest_granting; + else + avd->seqno = 0; + avd->flags = 0; +} + +static void update_xperms_extended_data(u8 specified, + const struct extended_perms_data *from, + struct extended_perms_data *xp_data) +{ + unsigned int i; + + switch (specified) { + case AVTAB_XPERMS_IOCTLDRIVER: + memset(xp_data->p, 0xff, sizeof(xp_data->p)); + break; + case AVTAB_XPERMS_IOCTLFUNCTION: + case AVTAB_XPERMS_NLMSG: + for (i = 0; i < ARRAY_SIZE(xp_data->p); i++) + xp_data->p[i] |= from->p[i]; + break; + } + +} + +void services_compute_xperms_decision(struct extended_perms_decision *xpermd, + struct avtab_node *node) +{ + u16 specified; + + switch (node->datum.u.xperms->specified) { + case AVTAB_XPERMS_IOCTLFUNCTION: + if (xpermd->base_perm != AVC_EXT_IOCTL || + xpermd->driver != node->datum.u.xperms->driver) + return; + break; + case AVTAB_XPERMS_IOCTLDRIVER: + if (xpermd->base_perm != AVC_EXT_IOCTL || + !security_xperm_test(node->datum.u.xperms->perms.p, + xpermd->driver)) + return; + break; + case AVTAB_XPERMS_NLMSG: + if (xpermd->base_perm != AVC_EXT_NLMSG || + xpermd->driver != node->datum.u.xperms->driver) + return; + break; + default: + pr_warn_once( + "SELinux: unknown extended permission (%u) will be ignored\n", + node->datum.u.xperms->specified); + return; + } + + specified = node->key.specified & ~(AVTAB_ENABLED | AVTAB_ENABLED_OLD); + + if (specified == AVTAB_XPERMS_ALLOWED) { + xpermd->used |= XPERMS_ALLOWED; + update_xperms_extended_data(node->datum.u.xperms->specified, + &node->datum.u.xperms->perms, + xpermd->allowed); + } else if (specified == AVTAB_XPERMS_AUDITALLOW) { + xpermd->used |= XPERMS_AUDITALLOW; + update_xperms_extended_data(node->datum.u.xperms->specified, + &node->datum.u.xperms->perms, + xpermd->auditallow); + } else if (specified == AVTAB_XPERMS_DONTAUDIT) { + xpermd->used |= XPERMS_DONTAUDIT; + update_xperms_extended_data(node->datum.u.xperms->specified, + &node->datum.u.xperms->perms, + xpermd->dontaudit); + } else { + pr_warn_once("SELinux: unknown specified key (%u)\n", + node->key.specified); + } +} + +void security_compute_xperms_decision(u32 ssid, + u32 tsid, + u16 orig_tclass, + u8 driver, + u8 base_perm, + struct extended_perms_decision *xpermd) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + u16 tclass; + struct context *scontext, *tcontext; + struct avtab_key avkey; + struct avtab_node *node; + struct ebitmap *sattr, *tattr; + struct ebitmap_node *snode, *tnode; + unsigned int i, j; + + xpermd->base_perm = base_perm; + xpermd->driver = driver; + xpermd->used = 0; + memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p)); + memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p)); + memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p)); + + rcu_read_lock(); + if (!selinux_initialized()) + goto allow; + + policy = rcu_dereference(selinux_state.policy); + policydb = &policy->policydb; + sidtab = policy->sidtab; + + scontext = sidtab_search(sidtab, ssid); + if (!scontext) { + pr_err("SELinux: %s: unrecognized SID %d\n", + __func__, ssid); + goto out; + } + + tcontext = sidtab_search(sidtab, tsid); + if (!tcontext) { + pr_err("SELinux: %s: unrecognized SID %d\n", + __func__, tsid); + goto out; + } + + tclass = unmap_class(&policy->map, orig_tclass); + if (unlikely(orig_tclass && !tclass)) { + if (policydb->allow_unknown) + goto allow; + goto out; + } + + + if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) { + pr_warn_ratelimited("SELinux: Invalid class %hu\n", tclass); + goto out; + } + + avkey.target_class = tclass; + avkey.specified = AVTAB_XPERMS; + sattr = &policydb->type_attr_map_array[scontext->type - 1]; + tattr = &policydb->type_attr_map_array[tcontext->type - 1]; + ebitmap_for_each_positive_bit(sattr, snode, i) { + ebitmap_for_each_positive_bit(tattr, tnode, j) { + avkey.source_type = i + 1; + avkey.target_type = j + 1; + for (node = avtab_search_node(&policydb->te_avtab, + &avkey); + node; + node = avtab_search_node_next(node, avkey.specified)) + services_compute_xperms_decision(xpermd, node); + + cond_compute_xperms(&policydb->te_cond_avtab, + &avkey, xpermd); + } + } +out: + rcu_read_unlock(); + return; +allow: + memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p)); + goto out; +} + +/** + * security_compute_av - Compute access vector decisions. + * @ssid: source security identifier + * @tsid: target security identifier + * @orig_tclass: target security class + * @avd: access vector decisions + * @xperms: extended permissions + * + * Compute a set of access vector decisions based on the + * SID pair (@ssid, @tsid) for the permissions in @tclass. + */ +void security_compute_av(u32 ssid, + u32 tsid, + u16 orig_tclass, + struct av_decision *avd, + struct extended_perms *xperms) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + u16 tclass; + struct context *scontext = NULL, *tcontext = NULL; + + rcu_read_lock(); + policy = rcu_dereference(selinux_state.policy); + avd_init(policy, avd); + xperms->len = 0; + if (!selinux_initialized()) + goto allow; + + policydb = &policy->policydb; + sidtab = policy->sidtab; + + scontext = sidtab_search(sidtab, ssid); + if (!scontext) { + pr_err("SELinux: %s: unrecognized SID %d\n", + __func__, ssid); + goto out; + } + + /* permissive domain? */ + if (ebitmap_get_bit(&policydb->permissive_map, scontext->type)) + avd->flags |= AVD_FLAGS_PERMISSIVE; + + /* neveraudit domain? */ + if (ebitmap_get_bit(&policydb->neveraudit_map, scontext->type)) + avd->flags |= AVD_FLAGS_NEVERAUDIT; + + /* both permissive and neveraudit => allow */ + if (avd->flags == (AVD_FLAGS_PERMISSIVE|AVD_FLAGS_NEVERAUDIT)) + goto allow; + + tcontext = sidtab_search(sidtab, tsid); + if (!tcontext) { + pr_err("SELinux: %s: unrecognized SID %d\n", + __func__, tsid); + goto out; + } + + tclass = unmap_class(&policy->map, orig_tclass); + if (unlikely(orig_tclass && !tclass)) { + if (policydb->allow_unknown) + goto allow; + goto out; + } + context_struct_compute_av(policydb, scontext, tcontext, tclass, avd, + xperms); + map_decision(&policy->map, orig_tclass, avd, + policydb->allow_unknown); +out: + rcu_read_unlock(); + if (avd->flags & AVD_FLAGS_NEVERAUDIT) + avd->auditallow = avd->auditdeny = 0; + return; +allow: + avd->allowed = 0xffffffff; + goto out; +} + +void security_compute_av_user(u32 ssid, + u32 tsid, + u16 tclass, + struct av_decision *avd) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + struct context *scontext = NULL, *tcontext = NULL; + + rcu_read_lock(); + policy = rcu_dereference(selinux_state.policy); + avd_init(policy, avd); + if (!selinux_initialized()) + goto allow; + + policydb = &policy->policydb; + sidtab = policy->sidtab; + + scontext = sidtab_search(sidtab, ssid); + if (!scontext) { + pr_err("SELinux: %s: unrecognized SID %d\n", + __func__, ssid); + goto out; + } + + /* permissive domain? */ + if (ebitmap_get_bit(&policydb->permissive_map, scontext->type)) + avd->flags |= AVD_FLAGS_PERMISSIVE; + + /* neveraudit domain? */ + if (ebitmap_get_bit(&policydb->neveraudit_map, scontext->type)) + avd->flags |= AVD_FLAGS_NEVERAUDIT; + + /* both permissive and neveraudit => allow */ + if (avd->flags == (AVD_FLAGS_PERMISSIVE|AVD_FLAGS_NEVERAUDIT)) + goto allow; + + tcontext = sidtab_search(sidtab, tsid); + if (!tcontext) { + pr_err("SELinux: %s: unrecognized SID %d\n", + __func__, tsid); + goto out; + } + + if (unlikely(!tclass)) { + if (policydb->allow_unknown) + goto allow; + goto out; + } + + context_struct_compute_av(policydb, scontext, tcontext, tclass, avd, + NULL); + out: + rcu_read_unlock(); + if (avd->flags & AVD_FLAGS_NEVERAUDIT) + avd->auditallow = avd->auditdeny = 0; + return; +allow: + avd->allowed = 0xffffffff; + goto out; +} + +/* + * Write the security context string representation of + * the context structure `context' into a dynamically + * allocated string of the correct size. Set `*scontext' + * to point to this string and set `*scontext_len' to + * the length of the string. + */ +static int context_struct_to_string(struct policydb *p, + struct context *context, + char **scontext, u32 *scontext_len) +{ + char *scontextp; + + if (scontext) + *scontext = NULL; + *scontext_len = 0; + + if (context->len) { + *scontext_len = context->len; + if (scontext) { + *scontext = kstrdup(context->str, GFP_ATOMIC); + if (!(*scontext)) + return -ENOMEM; + } + return 0; + } + + /* Compute the size of the context. */ + *scontext_len += strlen(sym_name(p, SYM_USERS, context->user - 1)) + 1; + *scontext_len += strlen(sym_name(p, SYM_ROLES, context->role - 1)) + 1; + *scontext_len += strlen(sym_name(p, SYM_TYPES, context->type - 1)) + 1; + *scontext_len += mls_compute_context_len(p, context); + + if (!scontext) + return 0; + + /* Allocate space for the context; caller must free this space. */ + scontextp = kmalloc(*scontext_len, GFP_ATOMIC); + if (!scontextp) + return -ENOMEM; + *scontext = scontextp; + + /* + * Copy the user name, role name and type name into the context. + */ + scontextp += sprintf(scontextp, "%s:%s:%s", + sym_name(p, SYM_USERS, context->user - 1), + sym_name(p, SYM_ROLES, context->role - 1), + sym_name(p, SYM_TYPES, context->type - 1)); + + mls_sid_to_context(p, context, &scontextp); + + *scontextp = 0; + + return 0; +} + +static int sidtab_entry_to_string(struct policydb *p, + struct sidtab *sidtab, + struct sidtab_entry *entry, + char **scontext, u32 *scontext_len) +{ + int rc = sidtab_sid2str_get(sidtab, entry, scontext, scontext_len); + + if (rc != -ENOENT) + return rc; + + rc = context_struct_to_string(p, &entry->context, scontext, + scontext_len); + if (!rc && scontext) + sidtab_sid2str_put(sidtab, entry, *scontext, *scontext_len); + return rc; +} + +#include "initial_sid_to_string.h" + +int security_sidtab_hash_stats(char *page) +{ + struct selinux_policy *policy; + int rc; + + if (!selinux_initialized()) { + pr_err("SELinux: %s: called before initial load_policy\n", + __func__); + return -EINVAL; + } + + rcu_read_lock(); + policy = rcu_dereference(selinux_state.policy); + rc = sidtab_hash_stats(policy->sidtab, page); + rcu_read_unlock(); + + return rc; +} + +const char *security_get_initial_sid_context(u32 sid) +{ + if (unlikely(sid > SECINITSID_NUM)) + return NULL; + return initial_sid_to_string[sid]; +} + +static int security_sid_to_context_core(u32 sid, char **scontext, + u32 *scontext_len, bool force, + bool only_invalid) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + struct sidtab_entry *entry; + int rc = 0; + + if (scontext) + *scontext = NULL; + *scontext_len = 0; + + if (!selinux_initialized()) { + if (sid <= SECINITSID_NUM) { + char *scontextp; + const char *s; + + /* + * Before the policy is loaded, translate + * SECINITSID_INIT to "kernel", because systemd and + * libselinux < 2.6 take a getcon_raw() result that is + * both non-null and not "kernel" to mean that a policy + * is already loaded. + */ + if (sid == SECINITSID_INIT) + sid = SECINITSID_KERNEL; + + s = initial_sid_to_string[sid]; + if (!s) + return -EINVAL; + *scontext_len = strlen(s) + 1; + if (!scontext) + return 0; + scontextp = kmemdup(s, *scontext_len, GFP_ATOMIC); + if (!scontextp) + return -ENOMEM; + *scontext = scontextp; + return 0; + } + pr_err("SELinux: %s: called before initial " + "load_policy on unknown SID %d\n", __func__, sid); + return -EINVAL; + } + rcu_read_lock(); + policy = rcu_dereference(selinux_state.policy); + policydb = &policy->policydb; + sidtab = policy->sidtab; + + if (force) + entry = sidtab_search_entry_force(sidtab, sid); + else + entry = sidtab_search_entry(sidtab, sid); + if (!entry) { + pr_err("SELinux: %s: unrecognized SID %d\n", + __func__, sid); + rc = -EINVAL; + goto out_unlock; + } + if (only_invalid && !entry->context.len) + goto out_unlock; + + rc = sidtab_entry_to_string(policydb, sidtab, entry, scontext, + scontext_len); + +out_unlock: + rcu_read_unlock(); + return rc; + +} + +/** + * security_sid_to_context - Obtain a context for a given SID. + * @sid: security identifier, SID + * @scontext: security context + * @scontext_len: length in bytes + * + * Write the string representation of the context associated with @sid + * into a dynamically allocated string of the correct size. Set @scontext + * to point to this string and set @scontext_len to the length of the string. + */ +int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len) +{ + return security_sid_to_context_core(sid, scontext, + scontext_len, false, false); +} + +int security_sid_to_context_force(u32 sid, + char **scontext, u32 *scontext_len) +{ + return security_sid_to_context_core(sid, scontext, + scontext_len, true, false); +} + +/** + * security_sid_to_context_inval - Obtain a context for a given SID if it + * is invalid. + * @sid: security identifier, SID + * @scontext: security context + * @scontext_len: length in bytes + * + * Write the string representation of the context associated with @sid + * into a dynamically allocated string of the correct size, but only if the + * context is invalid in the current policy. Set @scontext to point to + * this string (or NULL if the context is valid) and set @scontext_len to + * the length of the string (or 0 if the context is valid). + */ +int security_sid_to_context_inval(u32 sid, + char **scontext, u32 *scontext_len) +{ + return security_sid_to_context_core(sid, scontext, + scontext_len, true, true); +} + +/* + * Caveat: Mutates scontext. + */ +static int string_to_context_struct(struct policydb *pol, + struct sidtab *sidtabp, + char *scontext, + struct context *ctx, + u32 def_sid) +{ + struct role_datum *role; + struct type_datum *typdatum; + struct user_datum *usrdatum; + char *scontextp, *p, oldc; + int rc = 0; + + context_init(ctx); + + /* Parse the security context. */ + + rc = -EINVAL; + scontextp = scontext; + + /* Extract the user. */ + p = scontextp; + while (*p && *p != ':') + p++; + + if (*p == 0) + goto out; + + *p++ = 0; + + usrdatum = symtab_search(&pol->p_users, scontextp); + if (!usrdatum) + goto out; + + ctx->user = usrdatum->value; + + /* Extract role. */ + scontextp = p; + while (*p && *p != ':') + p++; + + if (*p == 0) + goto out; + + *p++ = 0; + + role = symtab_search(&pol->p_roles, scontextp); + if (!role) + goto out; + ctx->role = role->value; + + /* Extract type. */ + scontextp = p; + while (*p && *p != ':') + p++; + oldc = *p; + *p++ = 0; + + typdatum = symtab_search(&pol->p_types, scontextp); + if (!typdatum || typdatum->attribute) + goto out; + + ctx->type = typdatum->value; + + rc = mls_context_to_sid(pol, oldc, p, ctx, sidtabp, def_sid); + if (rc) + goto out; + + /* Check the validity of the new context. */ + rc = -EINVAL; + if (!policydb_context_isvalid(pol, ctx)) + goto out; + rc = 0; +out: + if (rc) + context_destroy(ctx); + return rc; +} + +static int security_context_to_sid_core(const char *scontext, u32 scontext_len, + u32 *sid, u32 def_sid, gfp_t gfp_flags, + bool force) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + char *scontext2, *str = NULL; + struct context context; + int rc = 0; + + /* An empty security context is never valid. */ + if (!scontext_len) + return -EINVAL; + + /* Copy the string to allow changes and ensure a NUL terminator */ + scontext2 = kmemdup_nul(scontext, scontext_len, gfp_flags); + if (!scontext2) + return -ENOMEM; + + if (!selinux_initialized()) { + u32 i; + + for (i = 1; i < SECINITSID_NUM; i++) { + const char *s = initial_sid_to_string[i]; + + if (s && !strcmp(s, scontext2)) { + *sid = i; + goto out; + } + } + *sid = SECINITSID_KERNEL; + goto out; + } + *sid = SECSID_NULL; + + if (force) { + /* Save another copy for storing in uninterpreted form */ + rc = -ENOMEM; + str = kstrdup(scontext2, gfp_flags); + if (!str) + goto out; + } +retry: + rcu_read_lock(); + policy = rcu_dereference(selinux_state.policy); + policydb = &policy->policydb; + sidtab = policy->sidtab; + rc = string_to_context_struct(policydb, sidtab, scontext2, + &context, def_sid); + if (rc == -EINVAL && force) { + context.str = str; + context.len = strlen(str) + 1; + str = NULL; + } else if (rc) + goto out_unlock; + rc = sidtab_context_to_sid(sidtab, &context, sid); + if (rc == -ESTALE) { + rcu_read_unlock(); + if (context.str) { + str = context.str; + context.str = NULL; + } + context_destroy(&context); + goto retry; + } + context_destroy(&context); +out_unlock: + rcu_read_unlock(); +out: + kfree(scontext2); + kfree(str); + return rc; +} + +/** + * security_context_to_sid - Obtain a SID for a given security context. + * @scontext: security context + * @scontext_len: length in bytes + * @sid: security identifier, SID + * @gfp: context for the allocation + * + * Obtains a SID associated with the security context that + * has the string representation specified by @scontext. + * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient + * memory is available, or 0 on success. + */ +int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid, + gfp_t gfp) +{ + return security_context_to_sid_core(scontext, scontext_len, + sid, SECSID_NULL, gfp, false); +} + +int security_context_str_to_sid(const char *scontext, u32 *sid, gfp_t gfp) +{ + return security_context_to_sid(scontext, strlen(scontext), + sid, gfp); +} + +/** + * security_context_to_sid_default - Obtain a SID for a given security context, + * falling back to specified default if needed. + * + * @scontext: security context + * @scontext_len: length in bytes + * @sid: security identifier, SID + * @def_sid: default SID to assign on error + * @gfp_flags: the allocator get-free-page (GFP) flags + * + * Obtains a SID associated with the security context that + * has the string representation specified by @scontext. + * The default SID is passed to the MLS layer to be used to allow + * kernel labeling of the MLS field if the MLS field is not present + * (for upgrading to MLS without full relabel). + * Implicitly forces adding of the context even if it cannot be mapped yet. + * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient + * memory is available, or 0 on success. + */ +int security_context_to_sid_default(const char *scontext, u32 scontext_len, + u32 *sid, u32 def_sid, gfp_t gfp_flags) +{ + return security_context_to_sid_core(scontext, scontext_len, + sid, def_sid, gfp_flags, true); +} + +int security_context_to_sid_force(const char *scontext, u32 scontext_len, + u32 *sid) +{ + return security_context_to_sid_core(scontext, scontext_len, + sid, SECSID_NULL, GFP_KERNEL, true); +} + +static int compute_sid_handle_invalid_context( + struct selinux_policy *policy, + struct sidtab_entry *sentry, + struct sidtab_entry *tentry, + u16 tclass, + struct context *newcontext) +{ + struct policydb *policydb = &policy->policydb; + struct sidtab *sidtab = policy->sidtab; + char *s = NULL, *t = NULL, *n = NULL; + u32 slen, tlen, nlen; + struct audit_buffer *ab; + + if (sidtab_entry_to_string(policydb, sidtab, sentry, &s, &slen)) + goto out; + if (sidtab_entry_to_string(policydb, sidtab, tentry, &t, &tlen)) + goto out; + if (context_struct_to_string(policydb, newcontext, &n, &nlen)) + goto out; + ab = audit_log_start(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR); + if (!ab) + goto out; + audit_log_format(ab, + "op=security_compute_sid invalid_context="); + /* no need to record the NUL with untrusted strings */ + audit_log_n_untrustedstring(ab, n, nlen - 1); + audit_log_format(ab, " scontext=%s tcontext=%s tclass=%s", + s, t, sym_name(policydb, SYM_CLASSES, tclass-1)); + audit_log_end(ab); +out: + kfree(s); + kfree(t); + kfree(n); + if (!enforcing_enabled()) + return 0; + return -EACCES; +} + +static void filename_compute_type(struct policydb *policydb, + struct context *newcontext, + u32 stype, u32 ttype, u16 tclass, + const char *objname) +{ + struct filename_trans_key ft; + struct filename_trans_datum *datum; + + /* + * Most filename trans rules are going to live in specific directories + * like /dev or /var/run. This bitmap will quickly skip rule searches + * if the ttype does not contain any rules. + */ + if (!ebitmap_get_bit(&policydb->filename_trans_ttypes, ttype)) + return; + + ft.ttype = ttype; + ft.tclass = tclass; + ft.name = objname; + + datum = policydb_filenametr_search(policydb, &ft); + while (datum) { + if (ebitmap_get_bit(&datum->stypes, stype - 1)) { + newcontext->type = datum->otype; + return; + } + datum = datum->next; + } +} + +static int security_compute_sid(u32 ssid, + u32 tsid, + u16 orig_tclass, + u16 specified, + const char *objname, + u32 *out_sid, + bool kern) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + struct class_datum *cladatum; + struct context *scontext, *tcontext, newcontext; + struct sidtab_entry *sentry, *tentry; + struct avtab_key avkey; + struct avtab_node *avnode, *node; + u16 tclass; + int rc = 0; + bool sock; + + if (!selinux_initialized()) { + switch (orig_tclass) { + case SECCLASS_PROCESS: /* kernel value */ + *out_sid = ssid; + break; + default: + *out_sid = tsid; + break; + } + goto out; + } + +retry: + cladatum = NULL; + context_init(&newcontext); + + rcu_read_lock(); + + policy = rcu_dereference(selinux_state.policy); + + if (kern) { + tclass = unmap_class(&policy->map, orig_tclass); + sock = security_is_socket_class(orig_tclass); + } else { + tclass = orig_tclass; + sock = security_is_socket_class(map_class(&policy->map, + tclass)); + } + + policydb = &policy->policydb; + sidtab = policy->sidtab; + + sentry = sidtab_search_entry(sidtab, ssid); + if (!sentry) { + pr_err("SELinux: %s: unrecognized SID %d\n", + __func__, ssid); + rc = -EINVAL; + goto out_unlock; + } + tentry = sidtab_search_entry(sidtab, tsid); + if (!tentry) { + pr_err("SELinux: %s: unrecognized SID %d\n", + __func__, tsid); + rc = -EINVAL; + goto out_unlock; + } + + scontext = &sentry->context; + tcontext = &tentry->context; + + if (tclass && tclass <= policydb->p_classes.nprim) + cladatum = policydb->class_val_to_struct[tclass - 1]; + + /* Set the user identity. */ + switch (specified) { + case AVTAB_TRANSITION: + case AVTAB_CHANGE: + if (cladatum && cladatum->default_user == DEFAULT_TARGET) { + newcontext.user = tcontext->user; + } else { + /* notice this gets both DEFAULT_SOURCE and unset */ + /* Use the process user identity. */ + newcontext.user = scontext->user; + } + break; + case AVTAB_MEMBER: + /* Use the related object owner. */ + newcontext.user = tcontext->user; + break; + } + + /* Set the role to default values. */ + if (cladatum && cladatum->default_role == DEFAULT_SOURCE) { + newcontext.role = scontext->role; + } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) { + newcontext.role = tcontext->role; + } else { + if ((tclass == policydb->process_class) || sock) + newcontext.role = scontext->role; + else + newcontext.role = OBJECT_R_VAL; + } + + /* Set the type. + * Look for a type transition/member/change rule. + */ + avkey.source_type = scontext->type; + avkey.target_type = tcontext->type; + avkey.target_class = tclass; + avkey.specified = specified; + avnode = avtab_search_node(&policydb->te_avtab, &avkey); + + /* If no permanent rule, also check for enabled conditional rules */ + if (!avnode) { + node = avtab_search_node(&policydb->te_cond_avtab, &avkey); + for (; node; node = avtab_search_node_next(node, specified)) { + if (node->key.specified & AVTAB_ENABLED) { + avnode = node; + break; + } + } + } + + /* If a permanent rule is found, use the type from + * the type transition/member/change rule. Otherwise, + * set the type to its default values. + */ + if (avnode) { + newcontext.type = avnode->datum.u.data; + } else if (cladatum && cladatum->default_type == DEFAULT_SOURCE) { + newcontext.type = scontext->type; + } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) { + newcontext.type = tcontext->type; + } else { + if ((tclass == policydb->process_class) || sock) { + /* Use the type of process. */ + newcontext.type = scontext->type; + } else { + /* Use the type of the related object. */ + newcontext.type = tcontext->type; + } + } + + /* if we have a objname this is a file trans check so check those rules */ + if (objname) + filename_compute_type(policydb, &newcontext, scontext->type, + tcontext->type, tclass, objname); + + /* Check for class-specific changes. */ + if (specified & AVTAB_TRANSITION) { + /* Look for a role transition rule. */ + struct role_trans_datum *rtd; + struct role_trans_key rtk = { + .role = scontext->role, + .type = tcontext->type, + .tclass = tclass, + }; + + rtd = policydb_roletr_search(policydb, &rtk); + if (rtd) + newcontext.role = rtd->new_role; + } + + /* Set the MLS attributes. + This is done last because it may allocate memory. */ + rc = mls_compute_sid(policydb, scontext, tcontext, tclass, specified, + &newcontext, sock); + if (rc) + goto out_unlock; + + /* Check the validity of the context. */ + if (!policydb_context_isvalid(policydb, &newcontext)) { + rc = compute_sid_handle_invalid_context(policy, sentry, + tentry, tclass, + &newcontext); + if (rc) + goto out_unlock; + } + /* Obtain the sid for the context. */ + if (context_equal(scontext, &newcontext)) + *out_sid = ssid; + else if (context_equal(tcontext, &newcontext)) + *out_sid = tsid; + else { + rc = sidtab_context_to_sid(sidtab, &newcontext, out_sid); + if (rc == -ESTALE) { + rcu_read_unlock(); + context_destroy(&newcontext); + goto retry; + } + } +out_unlock: + rcu_read_unlock(); + context_destroy(&newcontext); +out: + return rc; +} + +/** + * security_transition_sid - Compute the SID for a new subject/object. + * @ssid: source security identifier + * @tsid: target security identifier + * @tclass: target security class + * @qstr: object name + * @out_sid: security identifier for new subject/object + * + * Compute a SID to use for labeling a new subject or object in the + * class @tclass based on a SID pair (@ssid, @tsid). + * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM + * if insufficient memory is available, or %0 if the new SID was + * computed successfully. + */ +int security_transition_sid(u32 ssid, u32 tsid, u16 tclass, + const struct qstr *qstr, u32 *out_sid) +{ + return security_compute_sid(ssid, tsid, tclass, + AVTAB_TRANSITION, + qstr ? qstr->name : NULL, out_sid, true); +} + +int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass, + const char *objname, u32 *out_sid) +{ + return security_compute_sid(ssid, tsid, tclass, + AVTAB_TRANSITION, + objname, out_sid, false); +} + +/** + * security_member_sid - Compute the SID for member selection. + * @ssid: source security identifier + * @tsid: target security identifier + * @tclass: target security class + * @out_sid: security identifier for selected member + * + * Compute a SID to use when selecting a member of a polyinstantiated + * object of class @tclass based on a SID pair (@ssid, @tsid). + * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM + * if insufficient memory is available, or %0 if the SID was + * computed successfully. + */ +int security_member_sid(u32 ssid, + u32 tsid, + u16 tclass, + u32 *out_sid) +{ + return security_compute_sid(ssid, tsid, tclass, + AVTAB_MEMBER, NULL, + out_sid, false); +} + +/** + * security_change_sid - Compute the SID for object relabeling. + * @ssid: source security identifier + * @tsid: target security identifier + * @tclass: target security class + * @out_sid: security identifier for selected member + * + * Compute a SID to use for relabeling an object of class @tclass + * based on a SID pair (@ssid, @tsid). + * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM + * if insufficient memory is available, or %0 if the SID was + * computed successfully. + */ +int security_change_sid(u32 ssid, + u32 tsid, + u16 tclass, + u32 *out_sid) +{ + return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL, + out_sid, false); +} + +static inline int convert_context_handle_invalid_context( + struct policydb *policydb, + struct context *context) +{ + char *s; + u32 len; + + if (enforcing_enabled()) + return -EINVAL; + + if (!context_struct_to_string(policydb, context, &s, &len)) { + pr_warn("SELinux: Context %s would be invalid if enforcing\n", + s); + kfree(s); + } + return 0; +} + +/** + * services_convert_context - Convert a security context across policies. + * @args: populated convert_context_args struct + * @oldc: original context + * @newc: converted context + * @gfp_flags: allocation flags + * + * Convert the values in the security context structure @oldc from the values + * specified in the policy @args->oldp to the values specified in the policy + * @args->newp, storing the new context in @newc, and verifying that the + * context is valid under the new policy. + */ +int services_convert_context(struct convert_context_args *args, + struct context *oldc, struct context *newc, + gfp_t gfp_flags) +{ + struct ocontext *oc; + struct role_datum *role; + struct type_datum *typdatum; + struct user_datum *usrdatum; + char *s; + u32 len; + int rc; + + if (oldc->str) { + s = kstrdup(oldc->str, gfp_flags); + if (!s) + return -ENOMEM; + + rc = string_to_context_struct(args->newp, NULL, s, newc, SECSID_NULL); + if (rc == -EINVAL) { + /* + * Retain string representation for later mapping. + * + * IMPORTANT: We need to copy the contents of oldc->str + * back into s again because string_to_context_struct() + * may have garbled it. + */ + memcpy(s, oldc->str, oldc->len); + context_init(newc); + newc->str = s; + newc->len = oldc->len; + return 0; + } + kfree(s); + if (rc) { + /* Other error condition, e.g. ENOMEM. */ + pr_err("SELinux: Unable to map context %s, rc = %d.\n", + oldc->str, -rc); + return rc; + } + pr_info("SELinux: Context %s became valid (mapped).\n", + oldc->str); + return 0; + } + + context_init(newc); + + /* Convert the user. */ + usrdatum = symtab_search(&args->newp->p_users, + sym_name(args->oldp, SYM_USERS, oldc->user - 1)); + if (!usrdatum) + goto bad; + newc->user = usrdatum->value; + + /* Convert the role. */ + role = symtab_search(&args->newp->p_roles, + sym_name(args->oldp, SYM_ROLES, oldc->role - 1)); + if (!role) + goto bad; + newc->role = role->value; + + /* Convert the type. */ + typdatum = symtab_search(&args->newp->p_types, + sym_name(args->oldp, SYM_TYPES, oldc->type - 1)); + if (!typdatum) + goto bad; + newc->type = typdatum->value; + + /* Convert the MLS fields if dealing with MLS policies */ + if (args->oldp->mls_enabled && args->newp->mls_enabled) { + rc = mls_convert_context(args->oldp, args->newp, oldc, newc); + if (rc) + goto bad; + } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) { + /* + * Switching between non-MLS and MLS policy: + * ensure that the MLS fields of the context for all + * existing entries in the sidtab are filled in with a + * suitable default value, likely taken from one of the + * initial SIDs. + */ + oc = args->newp->ocontexts[OCON_ISID]; + while (oc && oc->sid[0] != SECINITSID_UNLABELED) + oc = oc->next; + if (!oc) { + pr_err("SELinux: unable to look up" + " the initial SIDs list\n"); + goto bad; + } + rc = mls_range_set(newc, &oc->context[0].range); + if (rc) + goto bad; + } + + /* Check the validity of the new context. */ + if (!policydb_context_isvalid(args->newp, newc)) { + rc = convert_context_handle_invalid_context(args->oldp, oldc); + if (rc) + goto bad; + } + + return 0; +bad: + /* Map old representation to string and save it. */ + rc = context_struct_to_string(args->oldp, oldc, &s, &len); + if (rc) + return rc; + context_destroy(newc); + newc->str = s; + newc->len = len; + pr_info("SELinux: Context %s became invalid (unmapped).\n", + newc->str); + return 0; +} + +static void security_load_policycaps(struct selinux_policy *policy) +{ + struct policydb *p; + unsigned int i; + struct ebitmap_node *node; + + p = &policy->policydb; + + for (i = 0; i < ARRAY_SIZE(selinux_state.policycap); i++) + WRITE_ONCE(selinux_state.policycap[i], + ebitmap_get_bit(&p->policycaps, i)); + + for (i = 0; i < ARRAY_SIZE(selinux_policycap_names); i++) + pr_info("SELinux: policy capability %s=%d\n", + selinux_policycap_names[i], + ebitmap_get_bit(&p->policycaps, i)); + + ebitmap_for_each_positive_bit(&p->policycaps, node, i) { + if (i >= ARRAY_SIZE(selinux_policycap_names)) + pr_info("SELinux: unknown policy capability %u\n", + i); + } +} + +static int security_preserve_bools(struct selinux_policy *oldpolicy, + struct selinux_policy *newpolicy); + +static void selinux_policy_free(struct selinux_policy *policy) +{ + if (!policy) + return; + + sidtab_destroy(policy->sidtab); + kfree(policy->map.mapping); + policydb_destroy(&policy->policydb); + kfree(policy->sidtab); + kfree(policy); +} + +static void selinux_policy_cond_free(struct selinux_policy *policy) +{ + cond_policydb_destroy_dup(&policy->policydb); + kfree(policy); +} + +void selinux_policy_cancel(struct selinux_load_state *load_state) +{ + struct selinux_state *state = &selinux_state; + struct selinux_policy *oldpolicy; + + oldpolicy = rcu_dereference_protected(state->policy, + lockdep_is_held(&state->policy_mutex)); + + /* a first load has no outgoing policy and converted nothing */ + if (oldpolicy) + sidtab_cancel_convert(oldpolicy->sidtab); + selinux_policy_free(load_state->policy); + kfree(load_state->convert_data); +} + +static void selinux_notify_policy_change(u32 seqno) +{ + /* Flush external caches and notify userspace of policy load */ + avc_ss_reset(seqno); + selnl_notify_policyload(seqno); + selinux_status_update_policyload(seqno); + selinux_netlbl_cache_invalidate(); + selinux_xfrm_notify_policyload(); + selinux_ima_measure_state_locked(); +} + +void selinux_policy_commit(struct selinux_load_state *load_state) +{ + struct selinux_state *state = &selinux_state; + struct selinux_policy *oldpolicy, *newpolicy = load_state->policy; + unsigned long flags; + u32 seqno; + + oldpolicy = rcu_dereference_protected(state->policy, + lockdep_is_held(&state->policy_mutex)); + + /* If switching between different policy types, log MLS status */ + if (oldpolicy) { + if (oldpolicy->policydb.mls_enabled && !newpolicy->policydb.mls_enabled) + pr_info("SELinux: Disabling MLS support...\n"); + else if (!oldpolicy->policydb.mls_enabled && newpolicy->policydb.mls_enabled) + pr_info("SELinux: Enabling MLS support...\n"); + } + + /* Set latest granting seqno for new policy. */ + if (oldpolicy) + newpolicy->latest_granting = oldpolicy->latest_granting + 1; + else + newpolicy->latest_granting = 1; + seqno = newpolicy->latest_granting; + + /* Install the new policy. */ + if (oldpolicy) { + sidtab_freeze_begin(oldpolicy->sidtab, &flags); + rcu_assign_pointer(state->policy, newpolicy); + sidtab_freeze_end(oldpolicy->sidtab, &flags); + } else { + rcu_assign_pointer(state->policy, newpolicy); + } + + /* Load the policycaps from the new policy */ + security_load_policycaps(newpolicy); + + if (!selinux_initialized()) { + /* + * After first policy load, the security server is + * marked as initialized and ready to handle requests and + * any objects created prior to policy load are then labeled. + */ + selinux_mark_initialized(); + selinux_complete_init(); + } + + /* Free the old policy */ + synchronize_rcu(); + selinux_policy_free(oldpolicy); + kfree(load_state->convert_data); + + /* Notify others of the policy change */ + selinux_notify_policy_change(seqno); +} + +/** + * security_load_policy - Load a security policy configuration. + * @data: binary policy data + * @len: length of data in bytes + * @load_state: policy load state + * + * Load a new set of security policy configuration data, + * validate it and convert the SID table as necessary. + * This function will flush the access vector cache after + * loading the new policy. + */ +int security_load_policy(void *data, size_t len, + struct selinux_load_state *load_state) +{ + struct selinux_state *state = &selinux_state; + struct selinux_policy *newpolicy, *oldpolicy; + struct selinux_policy_convert_data *convert_data; + int rc = 0; + struct policy_file file = { data, len }, *fp = &file; + + newpolicy = kzalloc_obj(*newpolicy); + if (!newpolicy) + return -ENOMEM; + + newpolicy->sidtab = kzalloc_obj(*newpolicy->sidtab); + if (!newpolicy->sidtab) { + rc = -ENOMEM; + goto err_policy; + } + + rc = policydb_read(&newpolicy->policydb, fp); + if (rc) + goto err_sidtab; + + newpolicy->policydb.len = len; + rc = selinux_set_mapping(&newpolicy->policydb, secclass_map, + &newpolicy->map); + if (rc) + goto err_policydb; + + rc = policydb_load_isids(&newpolicy->policydb, newpolicy->sidtab); + if (rc) { + pr_err("SELinux: unable to load the initial SIDs\n"); + goto err_mapping; + } + + if (!selinux_initialized()) { + /* First policy load, so no need to preserve state from old policy */ + load_state->policy = newpolicy; + load_state->convert_data = NULL; + return 0; + } + + oldpolicy = rcu_dereference_protected(state->policy, + lockdep_is_held(&state->policy_mutex)); + + /* Preserve active boolean values from the old policy */ + rc = security_preserve_bools(oldpolicy, newpolicy); + if (rc) { + pr_err("SELinux: unable to preserve booleans\n"); + goto err_free_isids; + } + + /* + * Convert the internal representations of contexts + * in the new SID table. + */ + + convert_data = kmalloc_obj(*convert_data); + if (!convert_data) { + rc = -ENOMEM; + goto err_free_isids; + } + + convert_data->args.oldp = &oldpolicy->policydb; + convert_data->args.newp = &newpolicy->policydb; + + convert_data->sidtab_params.args = &convert_data->args; + convert_data->sidtab_params.target = newpolicy->sidtab; + + rc = sidtab_convert(oldpolicy->sidtab, &convert_data->sidtab_params); + if (rc) { + pr_err("SELinux: unable to convert the internal" + " representation of contexts in the new SID" + " table\n"); + goto err_free_convert_data; + } + + load_state->policy = newpolicy; + load_state->convert_data = convert_data; + return 0; + +err_free_convert_data: + kfree(convert_data); +err_free_isids: + sidtab_destroy(newpolicy->sidtab); +err_mapping: + kfree(newpolicy->map.mapping); +err_policydb: + policydb_destroy(&newpolicy->policydb); +err_sidtab: + kfree(newpolicy->sidtab); +err_policy: + kfree(newpolicy); + + return rc; +} + +/** + * ocontext_to_sid - Helper to safely get sid for an ocontext + * @sidtab: SID table + * @c: ocontext structure + * @index: index of the context entry (0 or 1) + * @out_sid: pointer to the resulting SID value + * + * For all ocontexts except OCON_ISID the SID fields are populated + * on-demand when needed. Since updating the SID value is an SMP-sensitive + * operation, this helper must be used to do that safely. + * + * WARNING: This function may return -ESTALE, indicating that the caller + * must retry the operation after re-acquiring the policy pointer! + */ +static int ocontext_to_sid(struct sidtab *sidtab, struct ocontext *c, + size_t index, u32 *out_sid) +{ + int rc; + u32 sid; + + /* Ensure the associated sidtab entry is visible to this thread. */ + sid = smp_load_acquire(&c->sid[index]); + if (!sid) { + rc = sidtab_context_to_sid(sidtab, &c->context[index], &sid); + if (rc) + return rc; + + /* + * Ensure the new sidtab entry is visible to other threads + * when they see the SID. + */ + smp_store_release(&c->sid[index], sid); + } + *out_sid = sid; + return 0; +} + +/** + * security_port_sid - Obtain the SID for a port. + * @protocol: protocol number + * @port: port number + * @out_sid: security identifier + */ +int security_port_sid(u8 protocol, u16 port, u32 *out_sid) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + struct ocontext *c; + int rc; + + if (!selinux_initialized()) { + *out_sid = SECINITSID_PORT; + return 0; + } + +retry: + rc = 0; + rcu_read_lock(); + policy = rcu_dereference(selinux_state.policy); + policydb = &policy->policydb; + sidtab = policy->sidtab; + + c = policydb->ocontexts[OCON_PORT]; + while (c) { + if (c->u.port.protocol == protocol && + c->u.port.low_port <= port && + c->u.port.high_port >= port) + break; + c = c->next; + } + + if (c) { + rc = ocontext_to_sid(sidtab, c, 0, out_sid); + if (rc == -ESTALE) { + rcu_read_unlock(); + goto retry; + } + if (rc) + goto out; + } else { + *out_sid = SECINITSID_PORT; + } + +out: + rcu_read_unlock(); + return rc; +} + +/** + * security_ib_pkey_sid - Obtain the SID for a pkey. + * @subnet_prefix: Subnet Prefix + * @pkey_num: pkey number + * @out_sid: security identifier + */ +int security_ib_pkey_sid(u64 subnet_prefix, u16 pkey_num, u32 *out_sid) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + struct ocontext *c; + int rc; + + if (!selinux_initialized()) { + *out_sid = SECINITSID_UNLABELED; + return 0; + } + +retry: + rc = 0; + rcu_read_lock(); + policy = rcu_dereference(selinux_state.policy); + policydb = &policy->policydb; + sidtab = policy->sidtab; + + c = policydb->ocontexts[OCON_IBPKEY]; + while (c) { + if (c->u.ibpkey.low_pkey <= pkey_num && + c->u.ibpkey.high_pkey >= pkey_num && + c->u.ibpkey.subnet_prefix == subnet_prefix) + break; + + c = c->next; + } + + if (c) { + rc = ocontext_to_sid(sidtab, c, 0, out_sid); + if (rc == -ESTALE) { + rcu_read_unlock(); + goto retry; + } + if (rc) + goto out; + } else + *out_sid = SECINITSID_UNLABELED; + +out: + rcu_read_unlock(); + return rc; +} + +/** + * security_ib_endport_sid - Obtain the SID for a subnet management interface. + * @dev_name: device name + * @port_num: port number + * @out_sid: security identifier + */ +int security_ib_endport_sid(const char *dev_name, u8 port_num, u32 *out_sid) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + struct ocontext *c; + int rc; + + if (!selinux_initialized()) { + *out_sid = SECINITSID_UNLABELED; + return 0; + } + +retry: + rc = 0; + rcu_read_lock(); + policy = rcu_dereference(selinux_state.policy); + policydb = &policy->policydb; + sidtab = policy->sidtab; + + c = policydb->ocontexts[OCON_IBENDPORT]; + while (c) { + if (c->u.ibendport.port == port_num && + !strncmp(c->u.ibendport.dev_name, + dev_name, + IB_DEVICE_NAME_MAX)) + break; + + c = c->next; + } + + if (c) { + rc = ocontext_to_sid(sidtab, c, 0, out_sid); + if (rc == -ESTALE) { + rcu_read_unlock(); + goto retry; + } + if (rc) + goto out; + } else + *out_sid = SECINITSID_UNLABELED; + +out: + rcu_read_unlock(); + return rc; +} + +/** + * security_netif_sid - Obtain the SID for a network interface. + * @name: interface name + * @if_sid: interface SID + */ +int security_netif_sid(const char *name, u32 *if_sid) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + int rc; + struct ocontext *c; + bool wildcard_support; + + if (!selinux_initialized()) { + *if_sid = SECINITSID_NETIF; + return 0; + } + +retry: + rc = 0; + rcu_read_lock(); + policy = rcu_dereference(selinux_state.policy); + policydb = &policy->policydb; + sidtab = policy->sidtab; + wildcard_support = ebitmap_get_bit(&policydb->policycaps, POLICYDB_CAP_NETIF_WILDCARD); + + c = policydb->ocontexts[OCON_NETIF]; + while (c) { + if (wildcard_support) { + if (match_wildcard(c->u.name, name)) + break; + } else { + if (strcmp(c->u.name, name) == 0) + break; + } + + c = c->next; + } + + if (c) { + rc = ocontext_to_sid(sidtab, c, 0, if_sid); + if (rc == -ESTALE) { + rcu_read_unlock(); + goto retry; + } + if (rc) + goto out; + } else + *if_sid = SECINITSID_NETIF; + +out: + rcu_read_unlock(); + return rc; +} + +static bool match_ipv6_addrmask(const u32 input[4], const u32 addr[4], const u32 mask[4]) +{ + int i; + + for (i = 0; i < 4; i++) + if (addr[i] != (input[i] & mask[i])) + return false; + + return true; +} + +/** + * security_node_sid - Obtain the SID for a node (host). + * @domain: communication domain aka address family + * @addrp: address + * @addrlen: address length in bytes + * @out_sid: security identifier + */ +int security_node_sid(u16 domain, + const void *addrp, + u32 addrlen, + u32 *out_sid) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + int rc; + struct ocontext *c; + + if (!selinux_initialized()) { + *out_sid = SECINITSID_NODE; + return 0; + } + +retry: + rcu_read_lock(); + policy = rcu_dereference(selinux_state.policy); + policydb = &policy->policydb; + sidtab = policy->sidtab; + + switch (domain) { + case AF_INET: { + u32 addr; + + rc = -EINVAL; + if (addrlen != sizeof(u32)) + goto out; + + addr = *((const u32 *)addrp); + + c = policydb->ocontexts[OCON_NODE]; + while (c) { + if (c->u.node.addr == (addr & c->u.node.mask)) + break; + c = c->next; + } + break; + } + + case AF_INET6: + rc = -EINVAL; + if (addrlen != sizeof(u64) * 2) + goto out; + c = policydb->ocontexts[OCON_NODE6]; + while (c) { + if (match_ipv6_addrmask(addrp, c->u.node6.addr, + c->u.node6.mask)) + break; + c = c->next; + } + break; + + default: + rc = 0; + *out_sid = SECINITSID_NODE; + goto out; + } + + if (c) { + rc = ocontext_to_sid(sidtab, c, 0, out_sid); + if (rc == -ESTALE) { + rcu_read_unlock(); + goto retry; + } + if (rc) + goto out; + } else { + *out_sid = SECINITSID_NODE; + } + + rc = 0; +out: + rcu_read_unlock(); + return rc; +} + +/** + * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem + * @policy: policy + * @fstype: filesystem type + * @path: path from root of mount + * @orig_sclass: file security class + * @sid: SID for path + * + * Obtain a SID to use for a file in a filesystem that + * cannot support xattr or use a fixed labeling behavior like + * transition SIDs or task SIDs. + * + * WARNING: This function may return -ESTALE, indicating that the caller + * must retry the operation after re-acquiring the policy pointer! + */ +static inline int __security_genfs_sid(struct selinux_policy *policy, + const char *fstype, + const char *path, + u16 orig_sclass, + u32 *sid) +{ + struct policydb *policydb = &policy->policydb; + struct sidtab *sidtab = policy->sidtab; + u16 sclass; + struct genfs *genfs; + struct ocontext *c; + int cmp = 0; + bool wildcard; + + while (path[0] == '/' && path[1] == '/') + path++; + + sclass = unmap_class(&policy->map, orig_sclass); + *sid = SECINITSID_UNLABELED; + + for (genfs = policydb->genfs; genfs; genfs = genfs->next) { + cmp = strcmp(fstype, genfs->fstype); + if (cmp <= 0) + break; + } + + if (!genfs || cmp) + return -ENOENT; + + wildcard = ebitmap_get_bit(&policy->policydb.policycaps, + POLICYDB_CAP_GENFS_SECLABEL_WILDCARD); + for (c = genfs->head; c; c = c->next) { + if (!c->v.sclass || sclass == c->v.sclass) { + if (wildcard) { + if (match_wildcard(c->u.name, path)) + break; + } else { + size_t len = strlen(c->u.name); + + if ((strncmp(c->u.name, path, len)) == 0) + break; + } + } + } + + if (!c) + return -ENOENT; + + return ocontext_to_sid(sidtab, c, 0, sid); +} + +/** + * security_genfs_sid - Obtain a SID for a file in a filesystem + * @fstype: filesystem type + * @path: path from root of mount + * @orig_sclass: file security class + * @sid: SID for path + * + * Acquire policy_rwlock before calling __security_genfs_sid() and release + * it afterward. + */ +int security_genfs_sid(const char *fstype, + const char *path, + u16 orig_sclass, + u32 *sid) +{ + struct selinux_policy *policy; + int retval; + + if (!selinux_initialized()) { + *sid = SECINITSID_UNLABELED; + return 0; + } + + do { + rcu_read_lock(); + policy = rcu_dereference(selinux_state.policy); + retval = __security_genfs_sid(policy, fstype, path, + orig_sclass, sid); + rcu_read_unlock(); + } while (retval == -ESTALE); + return retval; +} + +int selinux_policy_genfs_sid(struct selinux_policy *policy, + const char *fstype, + const char *path, + u16 orig_sclass, + u32 *sid) +{ + /* no lock required, policy is not yet accessible by other threads */ + return __security_genfs_sid(policy, fstype, path, orig_sclass, sid); +} + +/** + * security_fs_use - Determine how to handle labeling for a filesystem. + * @sb: superblock in question + */ +int security_fs_use(struct super_block *sb) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + int rc; + struct ocontext *c; + struct superblock_security_struct *sbsec = selinux_superblock(sb); + const char *fstype = sb->s_type->name; + + if (!selinux_initialized()) { + sbsec->behavior = SECURITY_FS_USE_NONE; + sbsec->sid = SECINITSID_UNLABELED; + return 0; + } + +retry: + rcu_read_lock(); + policy = rcu_dereference(selinux_state.policy); + policydb = &policy->policydb; + sidtab = policy->sidtab; + + c = policydb->ocontexts[OCON_FSUSE]; + while (c) { + if (strcmp(fstype, c->u.name) == 0) + break; + c = c->next; + } + + if (c) { + sbsec->behavior = c->v.behavior; + rc = ocontext_to_sid(sidtab, c, 0, &sbsec->sid); + if (rc == -ESTALE) { + rcu_read_unlock(); + goto retry; + } + if (rc) + goto out; + } else { + rc = __security_genfs_sid(policy, fstype, "/", + SECCLASS_DIR, &sbsec->sid); + if (rc == -ESTALE) { + rcu_read_unlock(); + goto retry; + } + if (rc) { + sbsec->behavior = SECURITY_FS_USE_NONE; + rc = 0; + } else { + sbsec->behavior = SECURITY_FS_USE_GENFS; + } + } + +out: + rcu_read_unlock(); + return rc; +} + +int security_get_bools(struct selinux_policy *policy, + u32 *len, char ***names, int **values) +{ + struct policydb *policydb; + u32 i; + int rc; + + policydb = &policy->policydb; + + *names = NULL; + *values = NULL; + + rc = 0; + *len = policydb->p_bools.nprim; + if (!*len) + goto out; + + rc = -ENOMEM; + *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC); + if (!*names) + goto err; + + rc = -ENOMEM; + *values = kzalloc_objs(int, *len, GFP_ATOMIC); + if (!*values) + goto err; + + for (i = 0; i < *len; i++) { + (*values)[i] = policydb->bool_val_to_struct[i]->state; + + rc = -ENOMEM; + (*names)[i] = kstrdup(sym_name(policydb, SYM_BOOLS, i), + GFP_ATOMIC); + if (!(*names)[i]) + goto err; + } + rc = 0; +out: + return rc; +err: + if (*names) { + for (i = 0; i < *len; i++) + kfree((*names)[i]); + kfree(*names); + } + kfree(*values); + *len = 0; + *names = NULL; + *values = NULL; + goto out; +} + + +int security_set_bools(u32 len, const int *values) +{ + struct selinux_state *state = &selinux_state; + struct selinux_policy *newpolicy, *oldpolicy; + int rc; + u32 i, seqno = 0; + + if (!selinux_initialized()) + return -EINVAL; + + oldpolicy = rcu_dereference_protected(state->policy, + lockdep_is_held(&state->policy_mutex)); + + /* Consistency check on number of booleans, should never fail */ + if (WARN_ON(len != oldpolicy->policydb.p_bools.nprim)) + return -EINVAL; + + newpolicy = kmemdup(oldpolicy, sizeof(*newpolicy), GFP_KERNEL); + if (!newpolicy) + return -ENOMEM; + + /* + * Deep copy only the parts of the policydb that might be + * modified as a result of changing booleans. + */ + rc = cond_policydb_dup(&newpolicy->policydb, &oldpolicy->policydb); + if (rc) { + kfree(newpolicy); + return -ENOMEM; + } + + /* Update the boolean states in the copy */ + for (i = 0; i < len; i++) { + int new_state = !!values[i]; + int old_state = newpolicy->policydb.bool_val_to_struct[i]->state; + + if (new_state != old_state) { + audit_log(audit_context(), GFP_ATOMIC, + AUDIT_MAC_CONFIG_CHANGE, + "bool=%s val=%d old_val=%d auid=%u ses=%u", + sym_name(&newpolicy->policydb, SYM_BOOLS, i), + new_state, + old_state, + from_kuid(&init_user_ns, audit_get_loginuid(current)), + audit_get_sessionid(current)); + newpolicy->policydb.bool_val_to_struct[i]->state = new_state; + } + } + + /* Re-evaluate the conditional rules in the copy */ + evaluate_cond_nodes(&newpolicy->policydb); + + /* Set latest granting seqno for new policy */ + newpolicy->latest_granting = oldpolicy->latest_granting + 1; + seqno = newpolicy->latest_granting; + + /* Install the new policy */ + rcu_assign_pointer(state->policy, newpolicy); + + /* + * Free the conditional portions of the old policydb + * that were copied for the new policy, and the oldpolicy + * structure itself but not what it references. + */ + synchronize_rcu(); + selinux_policy_cond_free(oldpolicy); + + /* Notify others of the policy change */ + selinux_notify_policy_change(seqno); + return 0; +} + +int security_get_bool_value(u32 index) +{ + struct selinux_policy *policy; + struct policydb *policydb; + int rc; + u32 len; + + if (!selinux_initialized()) + return 0; + + rcu_read_lock(); + policy = rcu_dereference(selinux_state.policy); + policydb = &policy->policydb; + + rc = -EFAULT; + len = policydb->p_bools.nprim; + if (index >= len) + goto out; + + rc = policydb->bool_val_to_struct[index]->state; +out: + rcu_read_unlock(); + return rc; +} + +static int security_preserve_bools(struct selinux_policy *oldpolicy, + struct selinux_policy *newpolicy) +{ + int rc, *bvalues = NULL; + char **bnames = NULL; + struct cond_bool_datum *booldatum; + u32 i, nbools = 0; + + rc = security_get_bools(oldpolicy, &nbools, &bnames, &bvalues); + if (rc) + goto out; + for (i = 0; i < nbools; i++) { + booldatum = symtab_search(&newpolicy->policydb.p_bools, + bnames[i]); + if (booldatum) + booldatum->state = bvalues[i]; + } + evaluate_cond_nodes(&newpolicy->policydb); + +out: + if (bnames) { + for (i = 0; i < nbools; i++) + kfree(bnames[i]); + } + kfree(bnames); + kfree(bvalues); + return rc; +} + +/* + * security_sid_mls_copy() - computes a new sid based on the given + * sid and the mls portion of mls_sid. + */ +int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + struct context *context1; + struct context *context2; + struct context newcon; + char *s; + u32 len; + int rc; + + if (!selinux_initialized()) { + *new_sid = sid; + return 0; + } + +retry: + rc = 0; + context_init(&newcon); + + rcu_read_lock(); + policy = rcu_dereference(selinux_state.policy); + policydb = &policy->policydb; + sidtab = policy->sidtab; + + if (!policydb->mls_enabled) { + *new_sid = sid; + goto out_unlock; + } + + rc = -EINVAL; + context1 = sidtab_search(sidtab, sid); + if (!context1) { + pr_err("SELinux: %s: unrecognized SID %d\n", + __func__, sid); + goto out_unlock; + } + + rc = -EINVAL; + context2 = sidtab_search(sidtab, mls_sid); + if (!context2) { + pr_err("SELinux: %s: unrecognized SID %d\n", + __func__, mls_sid); + goto out_unlock; + } + + newcon.user = context1->user; + newcon.role = context1->role; + newcon.type = context1->type; + rc = mls_context_cpy(&newcon, context2); + if (rc) + goto out_unlock; + + /* Check the validity of the new context. */ + if (!policydb_context_isvalid(policydb, &newcon)) { + rc = convert_context_handle_invalid_context(policydb, + &newcon); + if (rc) { + if (!context_struct_to_string(policydb, &newcon, &s, + &len)) { + struct audit_buffer *ab; + + ab = audit_log_start(audit_context(), + GFP_ATOMIC, + AUDIT_SELINUX_ERR); + audit_log_format(ab, + "op=security_sid_mls_copy invalid_context="); + /* don't record NUL with untrusted strings */ + audit_log_n_untrustedstring(ab, s, len - 1); + audit_log_end(ab); + kfree(s); + } + goto out_unlock; + } + } + rc = sidtab_context_to_sid(sidtab, &newcon, new_sid); + if (rc == -ESTALE) { + rcu_read_unlock(); + context_destroy(&newcon); + goto retry; + } +out_unlock: + rcu_read_unlock(); + context_destroy(&newcon); + return rc; +} + +/** + * security_net_peersid_resolve - Compare and resolve two network peer SIDs + * @nlbl_sid: NetLabel SID + * @nlbl_type: NetLabel labeling protocol type + * @xfrm_sid: XFRM SID + * @peer_sid: network peer sid + * + * Description: + * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be + * resolved into a single SID it is returned via @peer_sid and the function + * returns zero. Otherwise @peer_sid is set to SECSID_NULL and the function + * returns a negative value. A table summarizing the behavior is below: + * + * | function return | @sid + * ------------------------------+-----------------+----------------- + * no peer labels | 0 | SECSID_NULL + * single peer label | 0 | <peer_label> + * multiple, consistent labels | 0 | <peer_label> + * multiple, inconsistent labels | -<errno> | SECSID_NULL + * + */ +int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type, + u32 xfrm_sid, + u32 *peer_sid) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + int rc; + struct context *nlbl_ctx; + struct context *xfrm_ctx; + + *peer_sid = SECSID_NULL; + + /* handle the common (which also happens to be the set of easy) cases + * right away, these two if statements catch everything involving a + * single or absent peer SID/label */ + if (xfrm_sid == SECSID_NULL) { + *peer_sid = nlbl_sid; + return 0; + } + /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label + * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label + * is present */ + if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) { + *peer_sid = xfrm_sid; + return 0; + } + + if (!selinux_initialized()) + return 0; + + rcu_read_lock(); + policy = rcu_dereference(selinux_state.policy); + policydb = &policy->policydb; + sidtab = policy->sidtab; + + /* + * We don't need to check initialized here since the only way both + * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the + * security server was initialized and state->initialized was true. + */ + if (!policydb->mls_enabled) { + rc = 0; + goto out; + } + + rc = -EINVAL; + nlbl_ctx = sidtab_search(sidtab, nlbl_sid); + if (!nlbl_ctx) { + pr_err("SELinux: %s: unrecognized SID %d\n", + __func__, nlbl_sid); + goto out; + } + rc = -EINVAL; + xfrm_ctx = sidtab_search(sidtab, xfrm_sid); + if (!xfrm_ctx) { + pr_err("SELinux: %s: unrecognized SID %d\n", + __func__, xfrm_sid); + goto out; + } + rc = (mls_context_equal(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES); + if (rc) + goto out; + + /* at present NetLabel SIDs/labels really only carry MLS + * information so if the MLS portion of the NetLabel SID + * matches the MLS portion of the labeled XFRM SID/label + * then pass along the XFRM SID as it is the most + * expressive */ + *peer_sid = xfrm_sid; +out: + rcu_read_unlock(); + return rc; +} + +static int get_classes_callback(void *k, void *d, void *args) +{ + struct class_datum *datum = d; + char *name = k, **classes = args; + u16 value = datum->value - 1; + + classes[value] = kstrdup(name, GFP_ATOMIC); + if (!classes[value]) + return -ENOMEM; + + return 0; +} + +int security_get_classes(struct selinux_policy *policy, + char ***classes, u32 *nclasses) +{ + struct policydb *policydb; + u32 i; + int rc; + + policydb = &policy->policydb; + + rc = -ENOMEM; + *nclasses = policydb->p_classes.nprim; + *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC); + if (!*classes) + goto out; + + rc = hashtab_map(&policydb->p_classes.table, get_classes_callback, + *classes); + if (rc) + goto err; + + /* + * The class symtab may be sparse, which policydb_class_isvalid() exists + * to absorb; the callback fills this array by value, so an unclaimed + * one leaves a NULL that sel_make_classes() hands to sel_make_dir(). + */ + for (i = 0; i < *nclasses; i++) { + if (!(*classes)[i]) { + rc = -EINVAL; + goto err; + } + } + +out: + return rc; + +err: + for (i = 0; i < *nclasses; i++) + kfree((*classes)[i]); + kfree(*classes); + return rc; +} + +static int get_permissions_callback(void *k, void *d, void *args) +{ + struct perm_datum *datum = d; + char *name = k, **perms = args; + u32 value = datum->value - 1; + + perms[value] = kstrdup(name, GFP_ATOMIC); + if (!perms[value]) + return -ENOMEM; + + return 0; +} + +int security_get_permissions(struct selinux_policy *policy, + const char *class, char ***perms, u32 *nperms) +{ + struct policydb *policydb; + u32 i; + int rc; + struct class_datum *match; + + policydb = &policy->policydb; + + rc = -EINVAL; + match = symtab_search(&policydb->p_classes, class); + if (!match) { + pr_err("SELinux: %s: unrecognized class %s\n", + __func__, class); + goto out; + } + + rc = -ENOMEM; + *nperms = match->permissions.nprim; + *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC); + if (!*perms) + goto out; + + if (match->comdatum) { + rc = hashtab_map(&match->comdatum->permissions.table, + get_permissions_callback, *perms); + if (rc) + goto err; + } + + rc = hashtab_map(&match->permissions.table, get_permissions_callback, + *perms); + if (rc) + goto err; + +out: + return rc; + +err: + for (i = 0; i < *nperms; i++) + kfree((*perms)[i]); + kfree(*perms); + return rc; +} + +int security_get_reject_unknown(void) +{ + struct selinux_policy *policy; + int value; + + if (!selinux_initialized()) + return 0; + + rcu_read_lock(); + policy = rcu_dereference(selinux_state.policy); + value = policy->policydb.reject_unknown; + rcu_read_unlock(); + return value; +} + +int security_get_allow_unknown(void) +{ + struct selinux_policy *policy; + int value; + + if (!selinux_initialized()) + return 0; + + rcu_read_lock(); + policy = rcu_dereference(selinux_state.policy); + value = policy->policydb.allow_unknown; + rcu_read_unlock(); + return value; +} + +/** + * security_policycap_supported - Check for a specific policy capability + * @req_cap: capability + * + * Description: + * This function queries the currently loaded policy to see if it supports the + * capability specified by @req_cap. Returns true (1) if the capability is + * supported, false (0) if it isn't supported. + * + */ +int security_policycap_supported(unsigned int req_cap) +{ + struct selinux_policy *policy; + int rc; + + if (!selinux_initialized()) + return 0; + + rcu_read_lock(); + policy = rcu_dereference(selinux_state.policy); + rc = ebitmap_get_bit(&policy->policydb.policycaps, req_cap); + rcu_read_unlock(); + + return rc; +} + +struct selinux_audit_rule { + u32 au_seqno; + struct context au_ctxt; +}; + +int selinux_audit_rule_avc_callback(u32 event) +{ + if (event == AVC_CALLBACK_RESET) + return audit_update_lsm_rules(); + return 0; +} + +void selinux_audit_rule_free(void *vrule) +{ + struct selinux_audit_rule *rule = vrule; + + if (rule) { + context_destroy(&rule->au_ctxt); + kfree(rule); + } +} + +int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule, + gfp_t gfp) +{ + struct selinux_state *state = &selinux_state; + struct selinux_policy *policy; + struct policydb *policydb; + struct selinux_audit_rule *tmprule; + struct role_datum *roledatum; + struct type_datum *typedatum; + struct user_datum *userdatum; + struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule; + int rc = 0; + + *rule = NULL; + + if (!selinux_initialized()) + return -EOPNOTSUPP; + + switch (field) { + case AUDIT_SUBJ_USER: + case AUDIT_SUBJ_ROLE: + case AUDIT_SUBJ_TYPE: + case AUDIT_OBJ_USER: + case AUDIT_OBJ_ROLE: + case AUDIT_OBJ_TYPE: + /* only 'equals' and 'not equals' fit user, role, and type */ + if (op != Audit_equal && op != Audit_not_equal) + return -EINVAL; + break; + case AUDIT_SUBJ_SEN: + case AUDIT_SUBJ_CLR: + case AUDIT_OBJ_LEV_LOW: + case AUDIT_OBJ_LEV_HIGH: + /* we do not allow a range, indicated by the presence of '-' */ + if (strchr(rulestr, '-')) + return -EINVAL; + break; + default: + /* only the above fields are valid */ + return -EINVAL; + } + + tmprule = kzalloc_obj(struct selinux_audit_rule, gfp); + if (!tmprule) + return -ENOMEM; + context_init(&tmprule->au_ctxt); + + rcu_read_lock(); + policy = rcu_dereference(state->policy); + policydb = &policy->policydb; + tmprule->au_seqno = policy->latest_granting; + switch (field) { + case AUDIT_SUBJ_USER: + case AUDIT_OBJ_USER: + userdatum = symtab_search(&policydb->p_users, rulestr); + if (!userdatum) { + rc = -EINVAL; + goto err; + } + tmprule->au_ctxt.user = userdatum->value; + break; + case AUDIT_SUBJ_ROLE: + case AUDIT_OBJ_ROLE: + roledatum = symtab_search(&policydb->p_roles, rulestr); + if (!roledatum) { + rc = -EINVAL; + goto err; + } + tmprule->au_ctxt.role = roledatum->value; + break; + case AUDIT_SUBJ_TYPE: + case AUDIT_OBJ_TYPE: + typedatum = symtab_search(&policydb->p_types, rulestr); + if (!typedatum) { + rc = -EINVAL; + goto err; + } + tmprule->au_ctxt.type = typedatum->value; + break; + case AUDIT_SUBJ_SEN: + case AUDIT_SUBJ_CLR: + case AUDIT_OBJ_LEV_LOW: + case AUDIT_OBJ_LEV_HIGH: + rc = mls_from_string(policydb, rulestr, &tmprule->au_ctxt, + GFP_ATOMIC); + if (rc) + goto err; + break; + } + rcu_read_unlock(); + + *rule = tmprule; + return 0; + +err: + rcu_read_unlock(); + selinux_audit_rule_free(tmprule); + *rule = NULL; + return rc; +} + +/* Check to see if the rule contains any selinux fields */ +int selinux_audit_rule_known(struct audit_krule *rule) +{ + u32 i; + + for (i = 0; i < rule->field_count; i++) { + struct audit_field *f = &rule->fields[i]; + switch (f->type) { + case AUDIT_SUBJ_USER: + case AUDIT_SUBJ_ROLE: + case AUDIT_SUBJ_TYPE: + case AUDIT_SUBJ_SEN: + case AUDIT_SUBJ_CLR: + case AUDIT_OBJ_USER: + case AUDIT_OBJ_ROLE: + case AUDIT_OBJ_TYPE: + case AUDIT_OBJ_LEV_LOW: + case AUDIT_OBJ_LEV_HIGH: + return 1; + } + } + + return 0; +} + +int selinux_audit_rule_match(struct lsm_prop *prop, u32 field, u32 op, void *vrule) +{ + struct selinux_state *state = &selinux_state; + struct selinux_policy *policy; + struct context *ctxt; + struct mls_level *level; + struct selinux_audit_rule *rule = vrule; + int match = 0; + + if (unlikely(!rule)) { + WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n"); + return -ENOENT; + } + + if (!selinux_initialized()) + return 0; + + rcu_read_lock(); + + policy = rcu_dereference(state->policy); + + if (rule->au_seqno < policy->latest_granting) { + match = -ESTALE; + goto out; + } + + ctxt = sidtab_search(policy->sidtab, prop->selinux.secid); + if (unlikely(!ctxt)) { + WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n", + prop->selinux.secid); + match = -ENOENT; + goto out; + } + + /* a field/op pair that is not caught here will simply fall through + without a match */ + switch (field) { + case AUDIT_SUBJ_USER: + case AUDIT_OBJ_USER: + switch (op) { + case Audit_equal: + match = (ctxt->user == rule->au_ctxt.user); + break; + case Audit_not_equal: + match = (ctxt->user != rule->au_ctxt.user); + break; + } + break; + case AUDIT_SUBJ_ROLE: + case AUDIT_OBJ_ROLE: + switch (op) { + case Audit_equal: + match = (ctxt->role == rule->au_ctxt.role); + break; + case Audit_not_equal: + match = (ctxt->role != rule->au_ctxt.role); + break; + } + break; + case AUDIT_SUBJ_TYPE: + case AUDIT_OBJ_TYPE: + switch (op) { + case Audit_equal: + match = (ctxt->type == rule->au_ctxt.type); + break; + case Audit_not_equal: + match = (ctxt->type != rule->au_ctxt.type); + break; + } + break; + case AUDIT_SUBJ_SEN: + case AUDIT_SUBJ_CLR: + case AUDIT_OBJ_LEV_LOW: + case AUDIT_OBJ_LEV_HIGH: + level = ((field == AUDIT_SUBJ_SEN || + field == AUDIT_OBJ_LEV_LOW) ? + &ctxt->range.level[0] : &ctxt->range.level[1]); + switch (op) { + case Audit_equal: + match = mls_level_eq(&rule->au_ctxt.range.level[0], + level); + break; + case Audit_not_equal: + match = !mls_level_eq(&rule->au_ctxt.range.level[0], + level); + break; + case Audit_lt: + match = (mls_level_dom(&rule->au_ctxt.range.level[0], + level) && + !mls_level_eq(&rule->au_ctxt.range.level[0], + level)); + break; + case Audit_le: + match = mls_level_dom(&rule->au_ctxt.range.level[0], + level); + break; + case Audit_gt: + match = (mls_level_dom(level, + &rule->au_ctxt.range.level[0]) && + !mls_level_eq(level, + &rule->au_ctxt.range.level[0])); + break; + case Audit_ge: + match = mls_level_dom(level, + &rule->au_ctxt.range.level[0]); + break; + } + } + +out: + rcu_read_unlock(); + return match; +} + +#ifdef CONFIG_NETLABEL +/** + * security_netlbl_cache_add - Add an entry to the NetLabel cache + * @secattr: the NetLabel packet security attributes + * @sid: the SELinux SID + * + * Description: + * Attempt to cache the context in @ctx, which was derived from the packet in + * @skb, in the NetLabel subsystem cache. This function assumes @secattr has + * already been initialized. + * + */ +static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr, + u32 sid) +{ + u32 *sid_cache; + + sid_cache = kmalloc_obj(*sid_cache, GFP_ATOMIC); + if (sid_cache == NULL) + return; + secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC); + if (secattr->cache == NULL) { + kfree(sid_cache); + return; + } + + *sid_cache = sid; + secattr->cache->free = kfree; + secattr->cache->data = sid_cache; + secattr->flags |= NETLBL_SECATTR_CACHE; +} + +/** + * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID + * @secattr: the NetLabel packet security attributes + * @sid: the SELinux SID + * + * Description: + * Convert the given NetLabel security attributes in @secattr into a + * SELinux SID. If the @secattr field does not contain a full SELinux + * SID/context then use SECINITSID_NETMSG as the foundation. If possible the + * 'cache' field of @secattr is set and the CACHE flag is set; this is to + * allow the @secattr to be used by NetLabel to cache the secattr to SID + * conversion for future lookups. Returns zero on success, negative values on + * failure. + * + */ +int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr, + u32 *sid) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + int rc; + struct context *ctx; + struct context ctx_new; + + if (!selinux_initialized()) { + *sid = SECSID_NULL; + return 0; + } + +retry: + rc = 0; + rcu_read_lock(); + policy = rcu_dereference(selinux_state.policy); + policydb = &policy->policydb; + sidtab = policy->sidtab; + + if (secattr->flags & NETLBL_SECATTR_CACHE) + *sid = *(u32 *)secattr->cache->data; + else if (secattr->flags & NETLBL_SECATTR_SECID) + *sid = secattr->attr.secid; + else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) { + rc = -EIDRM; + ctx = sidtab_search(sidtab, SECINITSID_NETMSG); + if (ctx == NULL) + goto out; + + context_init(&ctx_new); + ctx_new.user = ctx->user; + ctx_new.role = ctx->role; + ctx_new.type = ctx->type; + mls_import_netlbl_lvl(policydb, &ctx_new, secattr); + if (secattr->flags & NETLBL_SECATTR_MLS_CAT) { + rc = mls_import_netlbl_cat(policydb, &ctx_new, secattr); + if (rc) + goto out; + } + rc = -EIDRM; + if (!mls_context_isvalid(policydb, &ctx_new)) { + ebitmap_destroy(&ctx_new.range.level[0].cat); + goto out; + } + + rc = sidtab_context_to_sid(sidtab, &ctx_new, sid); + ebitmap_destroy(&ctx_new.range.level[0].cat); + if (rc == -ESTALE) { + rcu_read_unlock(); + goto retry; + } + if (rc) + goto out; + + security_netlbl_cache_add(secattr, *sid); + } else + *sid = SECSID_NULL; + +out: + rcu_read_unlock(); + return rc; +} + +/** + * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr + * @sid: the SELinux SID + * @secattr: the NetLabel packet security attributes + * + * Description: + * Convert the given SELinux SID in @sid into a NetLabel security attribute. + * Returns zero on success, negative values on failure. + * + */ +int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr) +{ + struct selinux_policy *policy; + struct policydb *policydb; + int rc; + struct context *ctx; + + if (!selinux_initialized()) + return 0; + + rcu_read_lock(); + policy = rcu_dereference(selinux_state.policy); + policydb = &policy->policydb; + + rc = -ENOENT; + ctx = sidtab_search(policy->sidtab, sid); + if (ctx == NULL) + goto out; + + rc = -ENOMEM; + secattr->domain = kstrdup(sym_name(policydb, SYM_TYPES, ctx->type - 1), + GFP_ATOMIC); + if (secattr->domain == NULL) + goto out; + + secattr->attr.secid = sid; + secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID; + mls_export_netlbl_lvl(policydb, ctx, secattr); + rc = mls_export_netlbl_cat(policydb, ctx, secattr); +out: + rcu_read_unlock(); + return rc; +} +#endif /* CONFIG_NETLABEL */ + +/** + * __security_read_policy - read the policy. + * @policy: SELinux policy + * @data: binary policy data + * @len: length of data in bytes + * + */ +static int __security_read_policy(struct selinux_policy *policy, + void *data, size_t *len) +{ + int rc; + struct policy_file fp; + + fp.data = data; + fp.len = *len; + + rc = policydb_write(&policy->policydb, &fp); + if (rc) + return rc; + + *len = (unsigned long)fp.data - (unsigned long)data; + return 0; +} + +/** + * security_read_policy - read the policy. + * @data: binary policy data + * @len: length of data in bytes + * + */ +int security_read_policy(void **data, size_t *len) +{ + struct selinux_state *state = &selinux_state; + struct selinux_policy *policy; + + policy = rcu_dereference_protected( + state->policy, lockdep_is_held(&state->policy_mutex)); + if (!policy) + return -EINVAL; + + *len = policy->policydb.len; + *data = vmalloc_user(*len); + if (!*data) + return -ENOMEM; + + return __security_read_policy(policy, *data, len); +} + +/** + * security_read_state_kernel - read the policy. + * @data: binary policy data + * @len: length of data in bytes + * + * Allocates kernel memory for reading SELinux policy. + * This function is for internal use only and should not + * be used for returning data to user space. + * + * This function must be called with policy_mutex held. + */ +int security_read_state_kernel(void **data, size_t *len) +{ + int err; + struct selinux_state *state = &selinux_state; + struct selinux_policy *policy; + + policy = rcu_dereference_protected( + state->policy, lockdep_is_held(&state->policy_mutex)); + if (!policy) + return -EINVAL; + + *len = policy->policydb.len; + *data = vmalloc(*len); + if (!*data) + return -ENOMEM; + + err = __security_read_policy(policy, *data, len); + if (err) { + vfree(*data); + *data = NULL; + *len = 0; + } + return err; +} diff --git a/security/selinux/ss/services.h b/security/selinux/ss/services.h new file mode 100644 index 000000000..93358e7a6 --- /dev/null +++ b/security/selinux/ss/services.h @@ -0,0 +1,47 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Implementation of the security services. + * + * Author : Stephen Smalley, <stephen.smalley.work@gmail.com> + */ + +#ifndef _SS_SERVICES_H_ +#define _SS_SERVICES_H_ + +#include "policydb.h" + +/* Mapping for a single class */ +struct selinux_mapping { + u16 value; /* policy value for class */ + u16 num_perms; /* number of permissions in class */ + u32 perms[sizeof(u32) * 8]; /* policy values for permissions */ +}; + +/* Map for all of the classes, with array size */ +struct selinux_map { + struct selinux_mapping *mapping; /* indexed by class */ + u16 size; /* array size of mapping */ +}; + +struct selinux_policy { + struct sidtab *sidtab; + struct policydb policydb; + struct selinux_map map; + u32 latest_granting; +} __randomize_layout; + +struct convert_context_args { + struct policydb *oldp; + struct policydb *newp; +}; + +void services_compute_xperms_drivers(struct extended_perms *xperms, + struct avtab_node *node); +void services_compute_xperms_decision(struct extended_perms_decision *xpermd, + struct avtab_node *node); + +int services_convert_context(struct convert_context_args *args, + struct context *oldc, struct context *newc, + gfp_t gfp_flags); + +#endif /* _SS_SERVICES_H_ */ diff --git a/security/selinux/ss/sidtab.c b/security/selinux/ss/sidtab.c new file mode 100644 index 000000000..118af0aa2 --- /dev/null +++ b/security/selinux/ss/sidtab.c @@ -0,0 +1,638 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Implementation of the SID table type. + * + * Original author: Stephen Smalley, <stephen.smalley.work@gmail.com> + * Author: Ondrej Mosnacek, <omosnacek@gmail.com> + * + * Copyright (C) 2018 Red Hat, Inc. + */ + +#include <linux/errno.h> +#include <linux/kernel.h> +#include <linux/list.h> +#include <linux/rcupdate.h> +#include <linux/slab.h> +#include <linux/sched.h> +#include <linux/spinlock.h> +#include <asm/barrier.h> +#include "flask.h" +#include "security.h" +#include "sidtab.h" +#include "services.h" + +struct sidtab_str_cache { + struct rcu_head rcu_member; + struct list_head lru_member; + struct sidtab_entry *parent; + u32 len; + char str[] __counted_by(len); +}; + +#define index_to_sid(index) ((index) + SECINITSID_NUM + 1) +#define sid_to_index(sid) ((sid) - (SECINITSID_NUM + 1)) + +int sidtab_init(struct sidtab *s) +{ + u32 i; + + memset(s->roots, 0, sizeof(s->roots)); + + for (i = 0; i < SECINITSID_NUM; i++) + s->isids[i].set = 0; + + s->frozen = false; + s->count = 0; + s->convert = NULL; + hash_init(s->context_to_sid); + + spin_lock_init(&s->lock); + +#if CONFIG_SECURITY_SELINUX_SID2STR_CACHE_SIZE > 0 + s->cache_free_slots = CONFIG_SECURITY_SELINUX_SID2STR_CACHE_SIZE; + INIT_LIST_HEAD(&s->cache_lru_list); + spin_lock_init(&s->cache_lock); +#endif + + return 0; +} + +static u32 context_to_sid(struct sidtab *s, struct context *context, u32 hash) +{ + struct sidtab_entry *entry; + u32 sid = 0; + + rcu_read_lock(); + hash_for_each_possible_rcu(s->context_to_sid, entry, list, hash) { + if (entry->hash != hash) + continue; + if (context_equal(&entry->context, context)) { + sid = entry->sid; + break; + } + } + rcu_read_unlock(); + return sid; +} + +int sidtab_set_initial(struct sidtab *s, u32 sid, struct context *context) +{ + struct sidtab_isid_entry *isid; + u32 hash; + int rc; + + if (sid == 0 || sid > SECINITSID_NUM) + return -EINVAL; + + isid = &s->isids[sid - 1]; + + rc = context_cpy(&isid->entry.context, context); + if (rc) + return rc; + +#if CONFIG_SECURITY_SELINUX_SID2STR_CACHE_SIZE > 0 + isid->entry.cache = NULL; +#endif + isid->set = 1; + + hash = context_compute_hash(context); + + /* + * Multiple initial sids may map to the same context. Check that this + * context is not already represented in the context_to_sid hashtable + * to avoid duplicate entries and long linked lists upon hash + * collision. + */ + if (!context_to_sid(s, context, hash)) { + isid->entry.sid = sid; + isid->entry.hash = hash; + hash_add(s->context_to_sid, &isid->entry.list, hash); + } + + return 0; +} + +int sidtab_hash_stats(struct sidtab *sidtab, char *page) +{ + unsigned int i; + int chain_len = 0; + int slots_used = 0; + int entries = 0; + int max_chain_len = 0; + unsigned int cur_bucket = 0; + struct sidtab_entry *entry; + + rcu_read_lock(); + hash_for_each_rcu(sidtab->context_to_sid, i, entry, list) { + entries++; + if (i == cur_bucket) { + chain_len++; + if (chain_len == 1) + slots_used++; + } else { + cur_bucket = i; + if (chain_len > max_chain_len) + max_chain_len = chain_len; + chain_len = 0; + } + } + rcu_read_unlock(); + + if (chain_len > max_chain_len) + max_chain_len = chain_len; + + return scnprintf(page, PAGE_SIZE, + "entries: %d\nbuckets used: %d/%d\n" + "longest chain: %d\n", + entries, slots_used, SIDTAB_HASH_BUCKETS, + max_chain_len); +} + +static u32 sidtab_level_from_count(u32 count) +{ + u32 capacity = SIDTAB_LEAF_ENTRIES; + u32 level = 0; + + while (count > capacity) { + capacity <<= SIDTAB_INNER_SHIFT; + ++level; + } + return level; +} + +static int sidtab_alloc_roots(struct sidtab *s, u32 level) +{ + u32 l; + + if (!s->roots[0].ptr_leaf) { + s->roots[0].ptr_leaf = + kzalloc(SIDTAB_NODE_ALLOC_SIZE, GFP_ATOMIC); + if (!s->roots[0].ptr_leaf) + return -ENOMEM; + } + for (l = 1; l <= level; ++l) + if (!s->roots[l].ptr_inner) { + s->roots[l].ptr_inner = + kzalloc(SIDTAB_NODE_ALLOC_SIZE, GFP_ATOMIC); + if (!s->roots[l].ptr_inner) + return -ENOMEM; + s->roots[l].ptr_inner->entries[0] = s->roots[l - 1]; + } + return 0; +} + +static struct sidtab_entry *sidtab_do_lookup(struct sidtab *s, u32 index, + int alloc) +{ + union sidtab_entry_inner *entry; + u32 level, capacity_shift, leaf_index = index / SIDTAB_LEAF_ENTRIES; + + /* find the level of the subtree we need */ + level = sidtab_level_from_count(index + 1); + capacity_shift = level * SIDTAB_INNER_SHIFT; + + /* allocate roots if needed */ + if (alloc && sidtab_alloc_roots(s, level) != 0) + return NULL; + + /* lookup inside the subtree */ + entry = &s->roots[level]; + while (level != 0) { + capacity_shift -= SIDTAB_INNER_SHIFT; + --level; + + entry = &entry->ptr_inner->entries[leaf_index >> capacity_shift]; + leaf_index &= ((u32)1 << capacity_shift) - 1; + + if (!entry->ptr_inner) { + if (alloc) + entry->ptr_inner = kzalloc( + SIDTAB_NODE_ALLOC_SIZE, GFP_ATOMIC); + if (!entry->ptr_inner) + return NULL; + } + } + if (!entry->ptr_leaf) { + if (alloc) + entry->ptr_leaf = + kzalloc(SIDTAB_NODE_ALLOC_SIZE, GFP_ATOMIC); + if (!entry->ptr_leaf) + return NULL; + } + return &entry->ptr_leaf->entries[index % SIDTAB_LEAF_ENTRIES]; +} + +static struct sidtab_entry *sidtab_lookup(struct sidtab *s, u32 index) +{ + /* read entries only after reading count */ + u32 count = smp_load_acquire(&s->count); + + if (index >= count) + return NULL; + + return sidtab_do_lookup(s, index, 0); +} + +static struct sidtab_entry *sidtab_lookup_initial(struct sidtab *s, u32 sid) +{ + return s->isids[sid - 1].set ? &s->isids[sid - 1].entry : NULL; +} + +static struct sidtab_entry *sidtab_search_core(struct sidtab *s, u32 sid, + int force) +{ + if (sid != 0) { + struct sidtab_entry *entry; + + if (sid > SECINITSID_NUM) + entry = sidtab_lookup(s, sid_to_index(sid)); + else + entry = sidtab_lookup_initial(s, sid); + if (entry && (!entry->context.len || force)) + return entry; + } + + return sidtab_lookup_initial(s, SECINITSID_UNLABELED); +} + +struct sidtab_entry *sidtab_search_entry(struct sidtab *s, u32 sid) +{ + return sidtab_search_core(s, sid, 0); +} + +struct sidtab_entry *sidtab_search_entry_force(struct sidtab *s, u32 sid) +{ + return sidtab_search_core(s, sid, 1); +} + +int sidtab_context_to_sid(struct sidtab *s, struct context *context, u32 *sid) +{ + unsigned long flags; + u32 count, hash = context_compute_hash(context); + struct sidtab_convert_params *convert; + struct sidtab_entry *dst, *dst_convert; + int rc; + + *sid = context_to_sid(s, context, hash); + if (*sid) + return 0; + + /* lock-free search failed: lock, re-search, and insert if not found */ + spin_lock_irqsave(&s->lock, flags); + + rc = 0; + *sid = context_to_sid(s, context, hash); + if (*sid) + goto out_unlock; + + if (unlikely(s->frozen)) { + /* + * This sidtab is now frozen - tell the caller to abort and + * get the new one. + */ + rc = -ESTALE; + goto out_unlock; + } + + count = s->count; + + /* bail out if we already reached max entries */ + rc = -EOVERFLOW; + if (count >= SIDTAB_MAX) + goto out_unlock; + + /* insert context into new entry */ + rc = -ENOMEM; + dst = sidtab_do_lookup(s, count, 1); + if (!dst) + goto out_unlock; + + dst->sid = index_to_sid(count); + dst->hash = hash; + + rc = context_cpy(&dst->context, context); + if (rc) + goto out_unlock; + + /* + * if we are building a new sidtab, we need to convert the context + * and insert it there as well + */ + convert = s->convert; + if (convert) { + struct sidtab *target = convert->target; + + rc = -ENOMEM; + dst_convert = sidtab_do_lookup(target, count, 1); + if (!dst_convert) { + context_destroy(&dst->context); + goto out_unlock; + } + + rc = services_convert_context(convert->args, context, + &dst_convert->context, + GFP_ATOMIC); + if (rc) { + context_destroy(&dst->context); + goto out_unlock; + } + dst_convert->sid = index_to_sid(count); + dst_convert->hash = context_compute_hash(&dst_convert->context); + target->count = count + 1; + + hash_add_rcu(target->context_to_sid, &dst_convert->list, + dst_convert->hash); + } + + if (context->len) + pr_info("SELinux: Context %s is not valid (left unmapped).\n", + context->str); + + *sid = index_to_sid(count); + + /* write entries before updating count */ + smp_store_release(&s->count, count + 1); + hash_add_rcu(s->context_to_sid, &dst->list, dst->hash); + + rc = 0; +out_unlock: + spin_unlock_irqrestore(&s->lock, flags); + return rc; +} + +static void sidtab_convert_hashtable(struct sidtab *s, u32 count) +{ + struct sidtab_entry *entry; + u32 i; + + for (i = 0; i < count; i++) { + entry = sidtab_do_lookup(s, i, 0); + entry->sid = index_to_sid(i); + entry->hash = context_compute_hash(&entry->context); + + hash_add_rcu(s->context_to_sid, &entry->list, entry->hash); + } +} + +static int sidtab_convert_tree(union sidtab_entry_inner *edst, + union sidtab_entry_inner *esrc, u32 *pos, + u32 count, u32 level, + struct sidtab_convert_params *convert) +{ + int rc; + u32 i; + + if (level != 0) { + if (!edst->ptr_inner) { + edst->ptr_inner = + kzalloc(SIDTAB_NODE_ALLOC_SIZE, GFP_KERNEL); + if (!edst->ptr_inner) + return -ENOMEM; + } + i = 0; + while (i < SIDTAB_INNER_ENTRIES && *pos < count) { + rc = sidtab_convert_tree(&edst->ptr_inner->entries[i], + &esrc->ptr_inner->entries[i], + pos, count, level - 1, + convert); + if (rc) + return rc; + i++; + } + } else { + if (!edst->ptr_leaf) { + edst->ptr_leaf = + kzalloc(SIDTAB_NODE_ALLOC_SIZE, GFP_KERNEL); + if (!edst->ptr_leaf) + return -ENOMEM; + } + i = 0; + while (i < SIDTAB_LEAF_ENTRIES && *pos < count) { + rc = services_convert_context( + convert->args, + &esrc->ptr_leaf->entries[i].context, + &edst->ptr_leaf->entries[i].context, + GFP_KERNEL); + if (rc) + return rc; + (*pos)++; + i++; + } + cond_resched(); + } + return 0; +} + +int sidtab_convert(struct sidtab *s, struct sidtab_convert_params *params) +{ + unsigned long flags; + u32 count, level, pos; + int rc; + + spin_lock_irqsave(&s->lock, flags); + + /* concurrent policy loads are not allowed */ + if (s->convert) { + spin_unlock_irqrestore(&s->lock, flags); + return -EBUSY; + } + + count = s->count; + level = sidtab_level_from_count(count); + + /* allocate last leaf in the new sidtab (to avoid race with + * live convert) + */ + rc = sidtab_do_lookup(params->target, count - 1, 1) ? 0 : -ENOMEM; + if (rc) { + spin_unlock_irqrestore(&s->lock, flags); + return rc; + } + + /* set count in case no new entries are added during conversion */ + params->target->count = count; + + /* enable live convert of new entries */ + s->convert = params; + + /* we can safely convert the tree outside the lock */ + spin_unlock_irqrestore(&s->lock, flags); + + pr_info("SELinux: Converting %u SID table entries...\n", count); + + /* convert all entries not covered by live convert */ + pos = 0; + rc = sidtab_convert_tree(¶ms->target->roots[level], + &s->roots[level], &pos, count, level, params); + if (rc) { + /* we need to keep the old table - disable live convert */ + spin_lock_irqsave(&s->lock, flags); + s->convert = NULL; + spin_unlock_irqrestore(&s->lock, flags); + return rc; + } + /* + * The hashtable can also be modified in sidtab_context_to_sid() + * so we must re-acquire the lock here. + */ + spin_lock_irqsave(&s->lock, flags); + sidtab_convert_hashtable(params->target, count); + spin_unlock_irqrestore(&s->lock, flags); + + return 0; +} + +void sidtab_cancel_convert(struct sidtab *s) +{ + unsigned long flags; + + /* cancelling policy load - disable live convert of sidtab */ + spin_lock_irqsave(&s->lock, flags); + s->convert = NULL; + spin_unlock_irqrestore(&s->lock, flags); +} + +void sidtab_freeze_begin(struct sidtab *s, unsigned long *flags) + __acquires(&s->lock) +{ + spin_lock_irqsave(&s->lock, *flags); + s->frozen = true; + s->convert = NULL; +} +void sidtab_freeze_end(struct sidtab *s, unsigned long *flags) + __releases(&s->lock) +{ + spin_unlock_irqrestore(&s->lock, *flags); +} + +static void sidtab_destroy_entry(struct sidtab_entry *entry) +{ + context_destroy(&entry->context); +#if CONFIG_SECURITY_SELINUX_SID2STR_CACHE_SIZE > 0 + kfree(rcu_dereference_raw(entry->cache)); +#endif +} + +static void sidtab_destroy_tree(union sidtab_entry_inner entry, u32 level) +{ + u32 i; + + if (level != 0) { + struct sidtab_node_inner *node = entry.ptr_inner; + + if (!node) + return; + + for (i = 0; i < SIDTAB_INNER_ENTRIES; i++) + sidtab_destroy_tree(node->entries[i], level - 1); + kfree(node); + } else { + struct sidtab_node_leaf *node = entry.ptr_leaf; + + if (!node) + return; + + for (i = 0; i < SIDTAB_LEAF_ENTRIES; i++) + sidtab_destroy_entry(&node->entries[i]); + kfree(node); + } +} + +void sidtab_destroy(struct sidtab *s) +{ + u32 i, level; + + for (i = 0; i < SECINITSID_NUM; i++) + if (s->isids[i].set) + sidtab_destroy_entry(&s->isids[i].entry); + + level = SIDTAB_MAX_LEVEL; + while (level && !s->roots[level].ptr_inner) + --level; + + sidtab_destroy_tree(s->roots[level], level); + /* + * The context_to_sid hashtable's objects are all shared + * with the isids array and context tree, and so don't need + * to be cleaned up here. + */ +} + +#if CONFIG_SECURITY_SELINUX_SID2STR_CACHE_SIZE > 0 + +void sidtab_sid2str_put(struct sidtab *s, struct sidtab_entry *entry, + const char *str, u32 str_len) +{ + struct sidtab_str_cache *cache, *victim = NULL; + unsigned long flags; + + /* do not cache invalid contexts */ + if (entry->context.len) + return; + + spin_lock_irqsave(&s->cache_lock, flags); + + cache = rcu_dereference_protected(entry->cache, + lockdep_is_held(&s->cache_lock)); + if (cache) { + /* entry in cache - just bump to the head of LRU list */ + list_move(&cache->lru_member, &s->cache_lru_list); + goto out_unlock; + } + + cache = kmalloc_flex(*cache, str, str_len, GFP_ATOMIC); + if (!cache) + goto out_unlock; + + if (s->cache_free_slots == 0) { + /* pop a cache entry from the tail and free it */ + victim = container_of(s->cache_lru_list.prev, + struct sidtab_str_cache, lru_member); + list_del(&victim->lru_member); + rcu_assign_pointer(victim->parent->cache, NULL); + } else { + s->cache_free_slots--; + } + cache->parent = entry; + cache->len = str_len; + memcpy(cache->str, str, str_len); + list_add(&cache->lru_member, &s->cache_lru_list); + + rcu_assign_pointer(entry->cache, cache); + +out_unlock: + spin_unlock_irqrestore(&s->cache_lock, flags); + kfree_rcu(victim, rcu_member); +} + +int sidtab_sid2str_get(struct sidtab *s, struct sidtab_entry *entry, char **out, + u32 *out_len) +{ + struct sidtab_str_cache *cache; + int rc = 0; + + if (entry->context.len) + return -ENOENT; /* do not cache invalid contexts */ + + rcu_read_lock(); + + cache = rcu_dereference(entry->cache); + if (!cache) { + rc = -ENOENT; + } else { + *out_len = cache->len; + if (out) { + *out = kmemdup(cache->str, cache->len, GFP_ATOMIC); + if (!*out) + rc = -ENOMEM; + } + } + + rcu_read_unlock(); + + if (!rc && out) + sidtab_sid2str_put(s, entry, *out, *out_len); + return rc; +} + +#endif /* CONFIG_SECURITY_SELINUX_SID2STR_CACHE_SIZE > 0 */ diff --git a/security/selinux/ss/sidtab.h b/security/selinux/ss/sidtab.h new file mode 100644 index 000000000..832c85c70 --- /dev/null +++ b/security/selinux/ss/sidtab.h @@ -0,0 +1,160 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * A security identifier table (sidtab) is a lookup table + * of security context structures indexed by SID value. + * + * Original author: Stephen Smalley, <stephen.smalley.work@gmail.com> + * Author: Ondrej Mosnacek, <omosnacek@gmail.com> + * + * Copyright (C) 2018 Red Hat, Inc. + */ + +#ifndef _SS_SIDTAB_H_ +#define _SS_SIDTAB_H_ + +#include <linux/spinlock_types.h> +#include <linux/log2.h> +#include <linux/hashtable.h> + +#include "context.h" + +struct sidtab_entry { + u32 sid; + u32 hash; + struct context context; +#if CONFIG_SECURITY_SELINUX_SID2STR_CACHE_SIZE > 0 + struct sidtab_str_cache __rcu *cache; +#endif + struct hlist_node list; +}; + +union sidtab_entry_inner { + struct sidtab_node_inner *ptr_inner; + struct sidtab_node_leaf *ptr_leaf; +}; + +/* align node size to page boundary */ +#define SIDTAB_NODE_ALLOC_SHIFT PAGE_SHIFT +#define SIDTAB_NODE_ALLOC_SIZE PAGE_SIZE + +#define size_to_shift(size) ((size) == 1 ? 1 : (const_ilog2((size)-1) + 1)) + +#define SIDTAB_INNER_SHIFT \ + (SIDTAB_NODE_ALLOC_SHIFT - \ + size_to_shift(sizeof(union sidtab_entry_inner))) +#define SIDTAB_INNER_ENTRIES ((size_t)1 << SIDTAB_INNER_SHIFT) +#define SIDTAB_LEAF_ENTRIES \ + (SIDTAB_NODE_ALLOC_SIZE / sizeof(struct sidtab_entry)) + +#define SIDTAB_MAX_BITS 32 +#define SIDTAB_MAX U32_MAX +/* ensure enough tree levels for SIDTAB_MAX entries */ +#define SIDTAB_MAX_LEVEL \ + DIV_ROUND_UP(SIDTAB_MAX_BITS - size_to_shift(SIDTAB_LEAF_ENTRIES), \ + SIDTAB_INNER_SHIFT) + +struct sidtab_node_leaf { + struct sidtab_entry entries[SIDTAB_LEAF_ENTRIES]; +}; + +struct sidtab_node_inner { + union sidtab_entry_inner entries[SIDTAB_INNER_ENTRIES]; +}; + +struct sidtab_isid_entry { + int set; + struct sidtab_entry entry; +}; + +struct sidtab_convert_params { + struct convert_context_args *args; + struct sidtab *target; +}; + +#define SIDTAB_HASH_BITS CONFIG_SECURITY_SELINUX_SIDTAB_HASH_BITS +#define SIDTAB_HASH_BUCKETS (1 << SIDTAB_HASH_BITS) + +struct sidtab { + /* + * lock-free read access only for as many items as a prior read of + * 'count' + */ + union sidtab_entry_inner roots[SIDTAB_MAX_LEVEL + 1]; + /* + * access atomically via {READ|WRITE}_ONCE(); only increment under + * spinlock + */ + u32 count; + /* access only under spinlock */ + struct sidtab_convert_params *convert; + bool frozen; + spinlock_t lock; + +#if CONFIG_SECURITY_SELINUX_SID2STR_CACHE_SIZE > 0 + /* SID -> context string cache */ + u32 cache_free_slots; + struct list_head cache_lru_list; + spinlock_t cache_lock; +#endif + + /* index == SID - 1 (no entry for SECSID_NULL) */ + struct sidtab_isid_entry isids[SECINITSID_NUM]; + + /* Hash table for fast reverse context-to-sid lookups. */ + DECLARE_HASHTABLE(context_to_sid, SIDTAB_HASH_BITS); +}; + +int sidtab_init(struct sidtab *s); +int sidtab_set_initial(struct sidtab *s, u32 sid, struct context *context); +struct sidtab_entry *sidtab_search_entry(struct sidtab *s, u32 sid); +struct sidtab_entry *sidtab_search_entry_force(struct sidtab *s, u32 sid); + +static inline struct context *sidtab_search(struct sidtab *s, u32 sid) +{ + struct sidtab_entry *entry = sidtab_search_entry(s, sid); + + return entry ? &entry->context : NULL; +} + +static inline struct context *sidtab_search_force(struct sidtab *s, u32 sid) +{ + struct sidtab_entry *entry = sidtab_search_entry_force(s, sid); + + return entry ? &entry->context : NULL; +} + +int sidtab_convert(struct sidtab *s, struct sidtab_convert_params *params); + +void sidtab_cancel_convert(struct sidtab *s); + +void sidtab_freeze_begin(struct sidtab *s, unsigned long *flags) + __acquires(&s->lock); +void sidtab_freeze_end(struct sidtab *s, unsigned long *flags) + __releases(&s->lock); + +int sidtab_context_to_sid(struct sidtab *s, struct context *context, u32 *sid); + +void sidtab_destroy(struct sidtab *s); + +int sidtab_hash_stats(struct sidtab *sidtab, char *page); + +#if CONFIG_SECURITY_SELINUX_SID2STR_CACHE_SIZE > 0 +void sidtab_sid2str_put(struct sidtab *s, struct sidtab_entry *entry, + const char *str, u32 str_len); +int sidtab_sid2str_get(struct sidtab *s, struct sidtab_entry *entry, char **out, + u32 *out_len); +#else +static inline void sidtab_sid2str_put(struct sidtab *s, + struct sidtab_entry *entry, + const char *str, u32 str_len) +{ +} +static inline int sidtab_sid2str_get(struct sidtab *s, + struct sidtab_entry *entry, char **out, + u32 *out_len) +{ + return -ENOENT; +} +#endif /* CONFIG_SECURITY_SELINUX_SID2STR_CACHE_SIZE > 0 */ + +#endif /* _SS_SIDTAB_H_ */ diff --git a/security/selinux/ss/symtab.c b/security/selinux/ss/symtab.c new file mode 100644 index 000000000..a756554e7 --- /dev/null +++ b/security/selinux/ss/symtab.c @@ -0,0 +1,56 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Implementation of the symbol table type. + * + * Author : Stephen Smalley, <stephen.smalley.work@gmail.com> + */ + +#include <linux/kernel.h> +#include <linux/string.h> +#include <linux/errno.h> +#include "symtab.h" + +static unsigned int symhash(const void *key) +{ + /* + * djb2a + * Public domain from cdb v0.75 + */ + unsigned int hash = 5381; + unsigned char c; + + while ((c = *(const unsigned char *)key++)) + hash = ((hash << 5) + hash) ^ c; + + return hash; +} + +static int symcmp(const void *key1, const void *key2) +{ + const char *keyp1, *keyp2; + + keyp1 = key1; + keyp2 = key2; + return strcmp(keyp1, keyp2); +} + +static const struct hashtab_key_params symtab_key_params = { + .hash = symhash, + .cmp = symcmp, +}; + +int symtab_init(struct symtab *s, u32 size) +{ + s->nprim = 0; + return hashtab_init(&s->table, size); +} + +int symtab_insert(struct symtab *s, char *name, void *datum) +{ + return hashtab_insert(&s->table, name, datum, symtab_key_params); +} + +void *symtab_search(const struct symtab *s, const char *name) +{ + return hashtab_search(&s->table, name, symtab_key_params); +} diff --git a/security/selinux/ss/symtab.h b/security/selinux/ss/symtab.h new file mode 100644 index 000000000..7cfa3b449 --- /dev/null +++ b/security/selinux/ss/symtab.h @@ -0,0 +1,26 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * A symbol table (symtab) maintains associations between symbol + * strings and datum values. The type of the datum values + * is arbitrary. The symbol table type is implemented + * using the hash table type (hashtab). + * + * Author : Stephen Smalley, <stephen.smalley.work@gmail.com> + */ + +#ifndef _SS_SYMTAB_H_ +#define _SS_SYMTAB_H_ + +#include "hashtab.h" + +struct symtab { + struct hashtab table; /* hash table (keyed on a string) */ + u32 nprim; /* number of primary names in table */ +}; + +int symtab_init(struct symtab *s, u32 size); + +int symtab_insert(struct symtab *s, char *name, void *datum); +void *symtab_search(const struct symtab *s, const char *name); + +#endif /* _SS_SYMTAB_H_ */ diff --git a/security/selinux/status.c b/security/selinux/status.c new file mode 100644 index 000000000..dffca22ce --- /dev/null +++ b/security/selinux/status.c @@ -0,0 +1,122 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * mmap based event notifications for SELinux + * + * Author: KaiGai Kohei <kaigai@ak.jp.nec.com> + * + * Copyright (C) 2010 NEC corporation + */ +#include <linux/kernel.h> +#include <linux/gfp.h> +#include <linux/mm.h> +#include <linux/mutex.h> +#include "avc.h" +#include "security.h" + +/* + * The selinux_status_page shall be exposed to userspace applications + * using mmap interface on /selinux/status. + * It enables to notify applications a few events that will cause reset + * of userspace access vector without context switching. + * + * The selinux_kernel_status structure on the head of status page is + * protected from concurrent accesses using seqlock logic, so userspace + * application should reference the status page according to the seqlock + * logic. + * + * Typically, application checks status->sequence at the head of access + * control routine. If it is odd-number, kernel is updating the status, + * so please wait for a moment. If it is changed from the last sequence + * number, it means something happen, so application will reset userspace + * avc, if needed. + * In most cases, application shall confirm the kernel status is not + * changed without any system call invocations. + */ + +/* + * selinux_kernel_status_page + * + * It returns a reference to selinux_status_page. If the status page is + * not allocated yet, it also tries to allocate it at the first time. + */ +struct page *selinux_kernel_status_page(void) +{ + struct selinux_kernel_status *status; + struct page *result = NULL; + + mutex_lock(&selinux_state.status_lock); + if (!selinux_state.status_page) { + selinux_state.status_page = alloc_page(GFP_KERNEL|__GFP_ZERO); + + if (selinux_state.status_page) { + status = page_address(selinux_state.status_page); + + status->version = SELINUX_KERNEL_STATUS_VERSION; + status->sequence = 0; + status->enforcing = enforcing_enabled(); + /* + * NOTE: the next policyload event shall set + * a positive value on the status->policyload, + * although it may not be 1, but never zero. + * So, application can know it was updated. + */ + status->policyload = 0; + status->deny_unknown = + !security_get_allow_unknown(); + } + } + result = selinux_state.status_page; + mutex_unlock(&selinux_state.status_lock); + + return result; +} + +/* + * selinux_status_update_setenforce + * + * It updates status of the current enforcing/permissive mode. + */ +void selinux_status_update_setenforce(bool enforcing) +{ + struct selinux_kernel_status *status; + + mutex_lock(&selinux_state.status_lock); + if (selinux_state.status_page) { + status = page_address(selinux_state.status_page); + + status->sequence++; + smp_wmb(); + + status->enforcing = enforcing ? 1 : 0; + + smp_wmb(); + status->sequence++; + } + mutex_unlock(&selinux_state.status_lock); +} + +/* + * selinux_status_update_policyload + * + * It updates status of the times of policy reloaded, and current + * setting of deny_unknown. + */ +void selinux_status_update_policyload(u32 seqno) +{ + struct selinux_kernel_status *status; + + mutex_lock(&selinux_state.status_lock); + if (selinux_state.status_page) { + status = page_address(selinux_state.status_page); + + status->sequence++; + smp_wmb(); + + status->policyload = seqno; + status->deny_unknown = !security_get_allow_unknown(); + + smp_wmb(); + status->sequence++; + } + mutex_unlock(&selinux_state.status_lock); +} diff --git a/security/selinux/xfrm.c b/security/selinux/xfrm.c new file mode 100644 index 000000000..8e00b3306 --- /dev/null +++ b/security/selinux/xfrm.c @@ -0,0 +1,466 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Security-Enhanced Linux (SELinux) security module + * + * This file contains the SELinux XFRM hook function implementations. + * + * Authors: Serge Hallyn <sergeh@us.ibm.com> + * Trent Jaeger <jaegert@us.ibm.com> + * + * Updated: Venkat Yekkirala <vyekkirala@TrustedCS.com> + * + * Granular IPSec Associations for use in MLS environments. + * + * Copyright (C) 2005 International Business Machines Corporation + * Copyright (C) 2006 Trusted Computer Solutions, Inc. + */ + +/* + * USAGE: + * NOTES: + * 1. Make sure to enable the following options in your kernel config: + * CONFIG_SECURITY=y + * CONFIG_SECURITY_NETWORK=y + * CONFIG_SECURITY_NETWORK_XFRM=y + * CONFIG_SECURITY_SELINUX=m/y + * ISSUES: + * 1. Caching packets, so they are not dropped during negotiation + * 2. Emulating a reasonable SO_PEERSEC across machines + * 3. Testing addition of sk_policy's with security context via setsockopt + */ +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/security.h> +#include <linux/types.h> +#include <linux/slab.h> +#include <linux/ip.h> +#include <linux/tcp.h> +#include <linux/skbuff.h> +#include <linux/xfrm.h> +#include <net/xfrm.h> +#include <net/checksum.h> +#include <net/udp.h> +#include <linux/atomic.h> + +#include "avc.h" +#include "objsec.h" +#include "xfrm.h" + +/* Labeled XFRM instance counter */ +atomic_t selinux_xfrm_refcount __read_mostly = ATOMIC_INIT(0); + +/* + * Returns true if the context is an LSM/SELinux context. + */ +static inline int selinux_authorizable_ctx(struct xfrm_sec_ctx *ctx) +{ + return (ctx && + (ctx->ctx_doi == XFRM_SC_DOI_LSM) && + (ctx->ctx_alg == XFRM_SC_ALG_SELINUX)); +} + +/* + * Returns true if the xfrm contains a security blob for SELinux. + */ +static inline int selinux_authorizable_xfrm(struct xfrm_state *x) +{ + return selinux_authorizable_ctx(x->security); +} + +/* + * Allocates a xfrm_sec_state and populates it using the supplied security + * xfrm_user_sec_ctx context. + */ +static int selinux_xfrm_alloc_user(struct xfrm_sec_ctx **ctxp, + struct xfrm_user_sec_ctx *uctx, + gfp_t gfp) +{ + int rc; + struct xfrm_sec_ctx *ctx = NULL; + u32 str_len; + + if (ctxp == NULL || uctx == NULL || + uctx->ctx_doi != XFRM_SC_DOI_LSM || + uctx->ctx_alg != XFRM_SC_ALG_SELINUX) + return -EINVAL; + + str_len = uctx->ctx_len; + if (str_len >= PAGE_SIZE) + return -ENOMEM; + + ctx = kmalloc_flex(*ctx, ctx_str, str_len + 1, gfp); + if (!ctx) + return -ENOMEM; + + ctx->ctx_doi = XFRM_SC_DOI_LSM; + ctx->ctx_alg = XFRM_SC_ALG_SELINUX; + ctx->ctx_len = str_len + 1; + memcpy(ctx->ctx_str, &uctx[1], str_len); + ctx->ctx_str[str_len] = '\0'; + rc = security_context_to_sid(ctx->ctx_str, str_len, + &ctx->ctx_sid, gfp); + if (rc) + goto err; + + rc = avc_has_perm(current_sid(), ctx->ctx_sid, + SECCLASS_ASSOCIATION, ASSOCIATION__SETCONTEXT, NULL); + if (rc) + goto err; + + *ctxp = ctx; + atomic_inc(&selinux_xfrm_refcount); + return 0; + +err: + kfree(ctx); + return rc; +} + +/* + * Free the xfrm_sec_ctx structure. + */ +static void selinux_xfrm_free(struct xfrm_sec_ctx *ctx) +{ + if (!ctx) + return; + + atomic_dec(&selinux_xfrm_refcount); + kfree(ctx); +} + +/* + * Authorize the deletion of a labeled SA or policy rule. + */ +static int selinux_xfrm_delete(struct xfrm_sec_ctx *ctx) +{ + if (!ctx) + return 0; + + return avc_has_perm(current_sid(), ctx->ctx_sid, + SECCLASS_ASSOCIATION, ASSOCIATION__SETCONTEXT, + NULL); +} + +/* + * LSM hook implementation that authorizes that a flow can use a xfrm policy + * rule. + */ +int selinux_xfrm_policy_lookup(struct xfrm_sec_ctx *ctx, u32 fl_secid) +{ + int rc; + + /* All flows should be treated as polmatch'ing an otherwise applicable + * "non-labeled" policy. This would prevent inadvertent "leaks". */ + if (!ctx) + return 0; + + /* Context sid is either set to label or ANY_ASSOC */ + if (!selinux_authorizable_ctx(ctx)) + return -EINVAL; + + rc = avc_has_perm(fl_secid, ctx->ctx_sid, + SECCLASS_ASSOCIATION, ASSOCIATION__POLMATCH, NULL); + return (rc == -EACCES ? -ESRCH : rc); +} + +/* + * LSM hook implementation that authorizes that a state matches + * the given policy, flow combo. + */ +int selinux_xfrm_state_pol_flow_match(struct xfrm_state *x, + struct xfrm_policy *xp, + const struct flowi_common *flic) +{ + u32 state_sid; + u32 flic_sid; + + if (!xp->security) + if (x->security) + /* unlabeled policy and labeled SA can't match */ + return 0; + else + /* unlabeled policy and unlabeled SA match all flows */ + return 1; + else + if (!x->security) + /* unlabeled SA and labeled policy can't match */ + return 0; + else + if (!selinux_authorizable_xfrm(x)) + /* Not a SELinux-labeled SA */ + return 0; + + state_sid = x->security->ctx_sid; + flic_sid = flic->flowic_secid; + + if (flic_sid != state_sid) + return 0; + + /* We don't need a separate SA Vs. policy polmatch check since the SA + * is now of the same label as the flow and a flow Vs. policy polmatch + * check had already happened in selinux_xfrm_policy_lookup() above. */ + return (avc_has_perm(flic_sid, state_sid, + SECCLASS_ASSOCIATION, ASSOCIATION__SENDTO, + NULL) ? 0 : 1); +} + +static u32 selinux_xfrm_skb_sid_egress(struct sk_buff *skb) +{ + struct dst_entry *dst = skb_dst(skb); + struct xfrm_state *x; + + if (dst == NULL) + return SECSID_NULL; + x = dst->xfrm; + if (x == NULL || !selinux_authorizable_xfrm(x)) + return SECSID_NULL; + + return x->security->ctx_sid; +} + +static int selinux_xfrm_skb_sid_ingress(struct sk_buff *skb, + u32 *sid, int ckall) +{ + u32 sid_session = SECSID_NULL; + struct sec_path *sp = skb_sec_path(skb); + + if (sp) { + int i; + + for (i = sp->len - 1; i >= 0; i--) { + struct xfrm_state *x = sp->xvec[i]; + if (selinux_authorizable_xfrm(x)) { + struct xfrm_sec_ctx *ctx = x->security; + + if (sid_session == SECSID_NULL) { + sid_session = ctx->ctx_sid; + if (!ckall) + goto out; + } else if (sid_session != ctx->ctx_sid) { + *sid = SECSID_NULL; + return -EINVAL; + } + } + } + } + +out: + *sid = sid_session; + return 0; +} + +/* + * LSM hook implementation that checks and/or returns the xfrm sid for the + * incoming packet. + */ +int selinux_xfrm_decode_session(struct sk_buff *skb, u32 *sid, int ckall) +{ + if (skb == NULL) { + *sid = SECSID_NULL; + return 0; + } + return selinux_xfrm_skb_sid_ingress(skb, sid, ckall); +} + +int selinux_xfrm_skb_sid(struct sk_buff *skb, u32 *sid) +{ + int rc; + + rc = selinux_xfrm_skb_sid_ingress(skb, sid, 0); + if (rc == 0 && *sid == SECSID_NULL) + *sid = selinux_xfrm_skb_sid_egress(skb); + + return rc; +} + +/* + * LSM hook implementation that allocs and transfers uctx spec to xfrm_policy. + */ +int selinux_xfrm_policy_alloc(struct xfrm_sec_ctx **ctxp, + struct xfrm_user_sec_ctx *uctx, + gfp_t gfp) +{ + return selinux_xfrm_alloc_user(ctxp, uctx, gfp); +} + +/* + * LSM hook implementation that copies security data structure from old to new + * for policy cloning. + */ +int selinux_xfrm_policy_clone(struct xfrm_sec_ctx *old_ctx, + struct xfrm_sec_ctx **new_ctxp) +{ + struct xfrm_sec_ctx *new_ctx; + + if (!old_ctx) + return 0; + + new_ctx = kmemdup(old_ctx, sizeof(*old_ctx) + old_ctx->ctx_len, + GFP_ATOMIC); + if (!new_ctx) + return -ENOMEM; + atomic_inc(&selinux_xfrm_refcount); + *new_ctxp = new_ctx; + + return 0; +} + +/* + * LSM hook implementation that frees xfrm_sec_ctx security information. + */ +void selinux_xfrm_policy_free(struct xfrm_sec_ctx *ctx) +{ + selinux_xfrm_free(ctx); +} + +/* + * LSM hook implementation that authorizes deletion of labeled policies. + */ +int selinux_xfrm_policy_delete(struct xfrm_sec_ctx *ctx) +{ + return selinux_xfrm_delete(ctx); +} + +/* + * LSM hook implementation that allocates a xfrm_sec_state, populates it using + * the supplied security context, and assigns it to the xfrm_state. + */ +int selinux_xfrm_state_alloc(struct xfrm_state *x, + struct xfrm_user_sec_ctx *uctx) +{ + return selinux_xfrm_alloc_user(&x->security, uctx, GFP_KERNEL); +} + +/* + * LSM hook implementation that allocates a xfrm_sec_state and populates based + * on a secid. + */ +int selinux_xfrm_state_alloc_acquire(struct xfrm_state *x, + struct xfrm_sec_ctx *polsec, u32 secid) +{ + int rc; + struct xfrm_sec_ctx *ctx; + char *ctx_str = NULL; + u32 str_len; + + if (!polsec) + return 0; + + if (secid == 0) + return -EINVAL; + + rc = security_sid_to_context(secid, &ctx_str, + &str_len); + if (rc) + return rc; + + ctx = kmalloc_flex(*ctx, ctx_str, str_len, GFP_ATOMIC); + if (!ctx) { + rc = -ENOMEM; + goto out; + } + + ctx->ctx_doi = XFRM_SC_DOI_LSM; + ctx->ctx_alg = XFRM_SC_ALG_SELINUX; + ctx->ctx_sid = secid; + ctx->ctx_len = str_len; + memcpy(ctx->ctx_str, ctx_str, str_len); + + x->security = ctx; + atomic_inc(&selinux_xfrm_refcount); +out: + kfree(ctx_str); + return rc; +} + +/* + * LSM hook implementation that frees xfrm_state security information. + */ +void selinux_xfrm_state_free(struct xfrm_state *x) +{ + selinux_xfrm_free(x->security); +} + +/* + * LSM hook implementation that authorizes deletion of labeled SAs. + */ +int selinux_xfrm_state_delete(struct xfrm_state *x) +{ + return selinux_xfrm_delete(x->security); +} + +/* + * LSM hook that controls access to unlabelled packets. If + * a xfrm_state is authorizable (defined by macro) then it was + * already authorized by the IPSec process. If not, then + * we need to check for unlabelled access since this may not have + * gone thru the IPSec process. + */ +int selinux_xfrm_sock_rcv_skb(u32 sk_sid, struct sk_buff *skb, + struct common_audit_data *ad) +{ + int i; + struct sec_path *sp = skb_sec_path(skb); + u32 peer_sid = SECINITSID_UNLABELED; + + if (sp) { + for (i = 0; i < sp->len; i++) { + struct xfrm_state *x = sp->xvec[i]; + + if (x && selinux_authorizable_xfrm(x)) { + struct xfrm_sec_ctx *ctx = x->security; + peer_sid = ctx->ctx_sid; + break; + } + } + } + + /* This check even when there's no association involved is intended, + * according to Trent Jaeger, to make sure a process can't engage in + * non-IPsec communication unless explicitly allowed by policy. */ + return avc_has_perm(sk_sid, peer_sid, + SECCLASS_ASSOCIATION, ASSOCIATION__RECVFROM, ad); +} + +/* + * POSTROUTE_LAST hook's XFRM processing: + * If we have no security association, then we need to determine + * whether the socket is allowed to send to an unlabelled destination. + * If we do have a authorizable security association, then it has already been + * checked in the selinux_xfrm_state_pol_flow_match hook above. + */ +int selinux_xfrm_postroute_last(u32 sk_sid, struct sk_buff *skb, + struct common_audit_data *ad, u8 proto) +{ + struct dst_entry *dst; + + switch (proto) { + case IPPROTO_AH: + case IPPROTO_ESP: + case IPPROTO_COMP: + /* We should have already seen this packet once before it + * underwent xfrm(s). No need to subject it to the unlabeled + * check. */ + return 0; + default: + break; + } + + dst = skb_dst(skb); + if (dst) { + struct dst_entry *iter; + + for (iter = dst; iter != NULL; iter = xfrm_dst_child(iter)) { + struct xfrm_state *x = iter->xfrm; + + if (x && selinux_authorizable_xfrm(x)) + return 0; + } + } + + /* This check even when there's no association involved is intended, + * according to Trent Jaeger, to make sure a process can't engage in + * non-IPsec communication unless explicitly allowed by policy. */ + return avc_has_perm(sk_sid, SECINITSID_UNLABELED, + SECCLASS_ASSOCIATION, ASSOCIATION__SENDTO, ad); +} |
