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

1 files changed, 514 insertions, 0 deletions

diff --git a/security/apparmor/lib.c b/security/apparmor/lib.c
new file mode 100644
index 000000000..73b88bde4
--- /dev/null
+++ b/security/apparmor/lib.c
@@ -0,0 +1,514 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * AppArmor security module
+ *
+ * This file contains basic common functions used in AppArmor
+ *
+ * Copyright (C) 1998-2008 Novell/SUSE
+ * Copyright 2009-2010 Canonical Ltd.
+ */
+
+#include <linux/ctype.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/vmalloc.h>
+
+#include "include/audit.h"
+#include "include/apparmor.h"
+#include "include/lib.h"
+#include "include/perms.h"
+#include "include/policy.h"
+
+const struct aa_perms nullperms;
+const struct aa_perms allperms = { .allow = ALL_PERMS_MASK,
+			     .quiet = ALL_PERMS_MASK,
+			     .hide = ALL_PERMS_MASK };
+
+struct val_table_ent {
+	const char *str;
+	int value;
+};
+
+static const struct val_table_ent debug_values_table[] = {
+	{ "N", DEBUG_NONE },
+	{ "none", DEBUG_NONE },
+	{ "n", DEBUG_NONE },
+	{ "0", DEBUG_NONE },
+	{ "all", DEBUG_ALL },
+	{ "Y", DEBUG_ALL },
+	{ "y", DEBUG_ALL },
+	{ "1", DEBUG_ALL },
+	{ "abs_root", DEBUG_LABEL_ABS_ROOT },
+	{ "label", DEBUG_LABEL },
+	{ "domain", DEBUG_DOMAIN },
+	{ "policy", DEBUG_POLICY },
+	{ "interface", DEBUG_INTERFACE },
+	{ "unpack", DEBUG_UNPACK },
+	{ "tags", DEBUG_TAGS },
+	{ NULL, 0 }
+};
+
+static const struct val_table_ent *
+val_table_find_ent(const struct val_table_ent *table,
+		   const char *name, size_t len)
+{
+	const struct val_table_ent *entry;
+
+	for (entry = table; entry->str != NULL; entry++) {
+		if (strncmp(entry->str, name, len) == 0 &&
+		    strlen(entry->str) == len)
+			return entry;
+	}
+	return NULL;
+}
+
+int aa_parse_debug_params(const char *str)
+{
+	const struct val_table_ent *ent;
+	const char *next;
+	int val = 0;
+
+	do {
+		size_t n = strcspn(str, "\r\n,");
+
+		next = str + n;
+		ent = val_table_find_ent(debug_values_table, str, next - str);
+		if (ent)
+			val |= ent->value;
+		else
+			AA_DEBUG(DEBUG_INTERFACE, "unknown debug type '%.*s'",
+				 (int)(next - str), str);
+		str = next + 1;
+	} while (*next != 0);
+	return val;
+}
+
+/**
+ * val_mask_to_str - convert a perm mask to its short string
+ * @str: character buffer to store string in (at least 10 characters)
+ * @size: size of the @str buffer
+ * @table: NUL-terminated character buffer of permission characters (NOT NULL)
+ * @mask: permission mask to convert
+ */
+static int val_mask_to_str(char *str, size_t size,
+			   const struct val_table_ent *table, u32 mask)
+{
+	const struct val_table_ent *ent;
+	int total = 0;
+
+	for (ent = table; ent->str; ent++) {
+		if (ent->value && (ent->value & mask) == ent->value) {
+			int len = scnprintf(str, size, "%s%s", total ? "," : "",
+					    ent->str);
+			size -= len;
+			str += len;
+			total += len;
+			mask &= ~ent->value;
+		}
+	}
+
+	return total;
+}
+
+int aa_print_debug_params(char *buffer)
+{
+	if (!aa_g_debug)
+		return sprintf(buffer, "N");
+	return val_mask_to_str(buffer, PAGE_SIZE, debug_values_table,
+			       aa_g_debug);
+}
+
+bool aa_resize_str_table(struct aa_str_table *t, int newsize, gfp_t gfp)
+{
+	struct aa_str_table_ent *n;
+	int i;
+
+	if (t->size == newsize)
+		return true;
+	n = kzalloc_objs(*n, newsize, gfp);
+	if (!n)
+		return false;
+	for (i = 0; i < min(t->size, newsize); i++)
+		n[i] = t->table[i];
+	for (; i < t->size; i++)
+		kfree_sensitive(t->table[i].strs);
+	if (newsize > t->size)
+		memset(&n[t->size], 0, (newsize-t->size)*sizeof(*n));
+	kfree_sensitive(t->table);
+	t->table = n;
+	t->size = newsize;
+
+	return true;
+}
+
+/**
+ * aa_destroy_str_table - free entries str table
+ * @t: the string table to free  (MAYBE NULL)
+ */
+void aa_destroy_str_table(struct aa_str_table *t)
+{
+	int i;
+
+	if (t) {
+		if (!t->table)
+			return;
+
+		for (i = 0; i < t->size; i++)
+			kfree_sensitive(t->table[i].strs);
+		kfree_sensitive(t->table);
+		t->table = NULL;
+		t->size = 0;
+	}
+}
+
+/**
+ * skipn_spaces - Removes leading whitespace from @str.
+ * @str: The string to be stripped.
+ * @n: length of str to parse, will stop at \0 if encountered before n
+ *
+ * Returns a pointer to the first non-whitespace character in @str.
+ * if all whitespace will return NULL
+ */
+
+const char *skipn_spaces(const char *str, size_t n)
+{
+	for (; n && isspace(*str); --n)
+		++str;
+	if (n)
+		return (char *)str;
+	return NULL;
+}
+
+const char *aa_splitn_fqname(const char *fqname, size_t n, const char **ns_name,
+			     size_t *ns_len)
+{
+	const char *end = fqname + n;
+	const char *name = skipn_spaces(fqname, n);
+
+	*ns_name = NULL;
+	*ns_len = 0;
+
+	if (!name)
+		return NULL;
+
+	if (name[0] == ':') {
+		char *split = strnchr(&name[1], end - &name[1], ':');
+		*ns_name = skipn_spaces(&name[1], end - &name[1]);
+		if (!*ns_name)
+			return NULL;
+		if (split) {
+			*ns_len = split - *ns_name;
+			if (*ns_len == 0)
+				*ns_name = NULL;
+			split++;
+			if (end - split > 1 && strncmp(split, "//", 2) == 0)
+				split += 2;
+			name = skipn_spaces(split, end - split);
+		} else {
+			/* a ns name without a following profile is allowed */
+			name = NULL;
+			*ns_len = end - *ns_name;
+		}
+	}
+	if (name && *name == 0)
+		name = NULL;
+
+	return name;
+}
+
+/**
+ * aa_info_message - log a none profile related status message
+ * @str: message to log
+ */
+void aa_info_message(const char *str)
+{
+	if (audit_enabled) {
+		DEFINE_AUDIT_DATA(ad, LSM_AUDIT_DATA_NONE, AA_CLASS_NONE, NULL);
+
+		ad.info = str;
+		aa_audit_msg(AUDIT_APPARMOR_STATUS, &ad, NULL);
+	}
+	printk(KERN_INFO "AppArmor: %s\n", str);
+}
+
+__counted char *aa_str_alloc(int size, gfp_t gfp)
+{
+	struct counted_str *str;
+
+	str = kmalloc_flex(*str, name, size, gfp);
+	if (!str)
+		return NULL;
+
+	kref_init(&str->count);
+	return str->name;
+}
+
+void aa_str_kref(struct kref *kref)
+{
+	kfree(container_of(kref, struct counted_str, count));
+}
+
+
+const char aa_file_perm_chrs[] = "xwracd         km l     ";
+const char *aa_file_perm_names[] = {
+	"exec",
+	"write",
+	"read",
+	"append",
+
+	"create",
+	"delete",
+	"open",
+	"rename",
+
+	"setattr",
+	"getattr",
+	"setcred",
+	"getcred",
+
+	"chmod",
+	"chown",
+	"chgrp",
+	"lock",
+
+	"mmap",
+	"mprot",
+	"link",
+	"snapshot",
+
+	"unknown",
+	"unknown",
+	"unknown",
+	"unknown",
+
+	"unknown",
+	"unknown",
+	"unknown",
+	"unknown",
+
+	"stack",
+	"change_onexec",
+	"change_profile",
+	"change_hat",
+};
+
+/**
+ * aa_perm_mask_to_str - convert a perm mask to its short string
+ * @str: character buffer to store string in (at least 10 characters)
+ * @str_size: size of the @str buffer
+ * @chrs: NUL-terminated character buffer of permission characters
+ * @mask: permission mask to convert
+ */
+void aa_perm_mask_to_str(char *str, size_t str_size, const char *chrs, u32 mask)
+{
+	unsigned int i, perm = 1;
+	size_t num_chrs = strlen(chrs);
+
+	for (i = 0; i < num_chrs; perm <<= 1, i++) {
+		if (mask & perm) {
+			/* Ensure that one byte is left for NUL-termination */
+			if (WARN_ON_ONCE(str_size <= 1))
+				break;
+
+			*str++ = chrs[i];
+			str_size--;
+		}
+	}
+	*str = '\0';
+}
+
+void aa_audit_perm_names(struct audit_buffer *ab, const char * const *names,
+			 u32 mask)
+{
+	const char *fmt = "%s";
+	unsigned int i, perm = 1;
+	bool prev = false;
+
+	for (i = 0; i < 32; perm <<= 1, i++) {
+		if (mask & perm) {
+			audit_log_format(ab, fmt, names[i]);
+			if (!prev) {
+				prev = true;
+				fmt = " %s";
+			}
+		}
+	}
+}
+
+void aa_audit_perm_mask(struct audit_buffer *ab, u32 mask, const char *chrs,
+			u32 chrsmask, const char * const *names, u32 namesmask)
+{
+	char str[33];
+
+	audit_log_format(ab, "\"");
+	if ((mask & chrsmask) && chrs) {
+		aa_perm_mask_to_str(str, sizeof(str), chrs, mask & chrsmask);
+		mask &= ~chrsmask;
+		audit_log_format(ab, "%s", str);
+		if (mask & namesmask)
+			audit_log_format(ab, " ");
+	}
+	if ((mask & namesmask) && names)
+		aa_audit_perm_names(ab, names, mask & namesmask);
+	audit_log_format(ab, "\"");
+}
+
+/**
+ * aa_apply_modes_to_perms - apply namespace and profile flags to perms
+ * @profile: that perms where computed from
+ * @perms: perms to apply mode modifiers to
+ *
+ * TODO: split into profile and ns based flags for when accumulating perms
+ */
+void aa_apply_modes_to_perms(const struct aa_profile *profile,
+			     struct aa_perms *perms)
+{
+	if (KILL_MODE(profile))
+		perms->kill = ~perms->allow;
+	else if (COMPLAIN_MODE(profile))
+		perms->complain |= ~(perms->allow | perms->deny);
+	else if (USER_MODE(profile))
+		perms->prompt |= ~(perms->allow | perms->deny);
+
+	switch (AUDIT_MODE(profile)) {
+	case AUDIT_ALL:
+		perms->audit = ALL_PERMS_MASK;
+		fallthrough;
+	case AUDIT_NOQUIET:
+		perms->quiet = 0;
+		break;
+	case AUDIT_QUIET:
+		perms->audit = 0;
+		fallthrough;
+	case AUDIT_QUIET_DENIED:
+		perms->quiet |= ~perms->allow;
+		break;
+	case AUDIT_QUIET_ALLOWED:
+		perms->quiet |= perms->complain | perms->allow;
+		break;
+	}
+}
+
+void aa_profile_match_label(const struct aa_profile *profile,
+			    struct aa_ruleset *rules,
+			    struct aa_label *label,
+			    int type, u32 request, struct aa_perms *perms)
+{
+	/* TODO: doesn't yet handle extended types */
+	aa_state_t state;
+
+	state = aa_dfa_next(rules->policy->dfa,
+			    rules->policy->start[AA_CLASS_LABEL],
+			    type);
+	aa_label_match(profile, rules, label, state, false, request, perms);
+}
+
+
+/**
+ * aa_check_perms - do audit mode selection based on perms set
+ * @profile: profile being checked
+ * @perms: perms computed for the request
+ * @request: requested perms
+ * @ad: initialized audit structure (MAY BE NULL if not auditing)
+ * @cb: callback fn for type specific fields (MAY BE NULL)
+ *
+ * Returns: 0 if permission else error code
+ *
+ * Note: profile audit modes need to be set before calling by setting the
+ *       perm masks appropriately.
+ *
+ *       If not auditing then complain mode is not enabled and the
+ *       error code will indicate whether there was an explicit deny
+ *	 with a positive value.
+ */
+int aa_check_perms(struct aa_profile *profile, const struct aa_perms *perms,
+		   u32 request, struct apparmor_audit_data *ad,
+		   void (*cb)(struct audit_buffer *, void *))
+{
+	int error;
+	u32 denied = request & (~perms->allow | perms->deny);
+
+	if (likely(!denied)) {
+		/* mask off perms that are not being force audited */
+		request &= perms->audit;
+		if (!request || !ad)
+			return 0;
+
+		error = 0;
+	} else {
+		error = -EACCES;
+
+		if (denied == (denied & perms->hide))
+			error = -ENOENT;
+
+		denied &= ~perms->quiet;
+		if (!ad || !denied)
+			return error;
+	}
+
+	int type = aa_select_audit_type(denied, perms);
+
+	if (ad) {
+		ad->subj_label = &profile->label;
+		ad->request = request;
+		ad->denied = denied;
+		ad->error = error;
+		aa_audit_msg(type, ad, cb);
+	}
+
+	if (type == AUDIT_APPARMOR_ALLOWED)
+		error = 0;
+
+	return error;
+}
+
+
+/**
+ * aa_policy_init - initialize a policy structure
+ * @policy: policy to initialize  (NOT NULL)
+ * @prefix: prefix name if any is required.  (MAYBE NULL)
+ * @name: name of the policy, init will make a copy of it  (NOT NULL)
+ * @gfp: allocation mode
+ *
+ * Note: this fn creates a copy of strings passed in
+ *
+ * Returns: true if policy init successful
+ */
+bool aa_policy_init(struct aa_policy *policy, const char *prefix,
+		    const char *name, gfp_t gfp)
+{
+	char *hname;
+	size_t hname_sz;
+
+	INIT_LIST_HEAD(&policy->list);
+	INIT_LIST_HEAD(&policy->profiles);
+	hname_sz = (prefix ? strlen(prefix) + 2 : 0) + strlen(name) + 1;
+	/* freed by policy_free */
+	hname = aa_str_alloc(hname_sz, gfp);
+	if (!hname)
+		return false;
+	if (prefix)
+		scnprintf(hname, hname_sz, "%s//%s", prefix, name);
+	else
+		strscpy(hname, name, hname_sz);
+	policy->hname = hname;
+	/* base.name is a substring of fqname */
+	policy->name = basename(policy->hname);
+
+	return true;
+}
+
+/**
+ * aa_policy_destroy - free the elements referenced by @policy
+ * @policy: policy that is to have its elements freed  (NOT NULL)
+ */
+void aa_policy_destroy(struct aa_policy *policy)
+{
+	AA_BUG(on_list_rcu(&policy->profiles));
+	AA_BUG(on_list_rcu(&policy->list));
+
+	/* don't free name as its a subset of hname */
+	aa_put_str(policy->hname);
+}
+