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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
commit4352b8aee98005853aa63f57d6377282de17a33f (patch)
tree27614d7a9ef05c32d089004e104364ce42324837 /security/landlock/ruleset.c
downloadlinux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz
linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni: "A new driver this cycle, for the AMD AXI I3C controller. There are also new features such as IBI wakeup support, SETAASA device discovery and ACPI support for the the DAA methods, meaning we can now communicate with the SPD devices on DDR5 modules. New driver: - AMD AXI I3C master controller Subsystem: - I3C Common Command Code (CCC) handling improvements, especially around GET CCCs - SETAASA device discovery support - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as well as I2C devices on I3C bus - IBI-based wakeup support Drivers: - dw: SETAASA support - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C controller support, PIO queue management support for HCI v1.2 - renesas: improve suspend to RAM support, add runtime PM support" * tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits) i3c: dw: reduce do_daa time if there's no client i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2 i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode i3c: dw: rename "pclk" to "apb" to match dt-binding i3c: dw: make struct dw_i3c_cmd smaller i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding i3c: renesas: Don't register devices when ENTDAA times out i3c: master: dw-i3c-master: fix OD timing for first broadcast i3c: mipi-i3c-hci: Advertise IBI wakeup capability i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev() i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI i3c: master: Reject IBI requests from non-IBI-capable devices i3c: master: Add helper to query bus wakeup requirements i3c: master: Report wakeup events for IBIs i3c: master: Support IBI-based wakeup capability i3c: master: Fix potential UAF in i3c_device_match() i3c: master: Fix potential UAF in i3c_device_uevent() i3c: Make dev->desc locking assumptions explicit i3c: master: Fix use-after-free of master->this ...
Diffstat (limited to 'security/landlock/ruleset.c')
-rw-r--r--security/landlock/ruleset.c354
1 files changed, 354 insertions, 0 deletions
diff --git a/security/landlock/ruleset.c b/security/landlock/ruleset.c
new file mode 100644
index 000000000..0d0770752
--- /dev/null
+++ b/security/landlock/ruleset.c
@@ -0,0 +1,354 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Landlock LSM - Ruleset management
+ *
+ * Copyright © 2016-2020 Mickaël Salaün <mic@digikod.net>
+ * Copyright © 2018-2020 ANSSI
+ * Copyright © 2026 Cloudflare, Inc.
+ */
+
+#include <linux/bits.h>
+#include <linux/bug.h>
+#include <linux/cleanup.h>
+#include <linux/compiler_types.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/lockdep.h>
+#include <linux/mutex.h>
+#include <linux/overflow.h>
+#include <linux/rbtree.h>
+#include <linux/refcount.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <uapi/linux/landlock.h>
+
+#include "access.h"
+#include "id.h"
+#include "limits.h"
+#include "object.h"
+#include "ruleset.h"
+
+#include <trace/events/landlock.h>
+
+struct landlock_ruleset *
+landlock_create_ruleset(const access_mask_t fs_access_mask,
+ const access_mask_t net_access_mask,
+ const access_mask_t scope_mask)
+{
+ struct landlock_ruleset *new_ruleset;
+
+ /* Informs about useless ruleset. */
+ if (!fs_access_mask && !net_access_mask && !scope_mask)
+ return ERR_PTR(-ENOMSG);
+
+ new_ruleset = kzalloc_obj(*new_ruleset, GFP_KERNEL_ACCOUNT);
+ if (!new_ruleset)
+ return ERR_PTR(-ENOMEM);
+
+ refcount_set(&new_ruleset->usage, 1);
+ mutex_init(&new_ruleset->lock);
+ new_ruleset->rules.root_inode = RB_ROOT;
+
+#if IS_ENABLED(CONFIG_INET)
+ new_ruleset->rules.root_net_port = RB_ROOT;
+#endif /* IS_ENABLED(CONFIG_INET) */
+
+#ifdef CONFIG_TRACEPOINTS
+ new_ruleset->id = landlock_get_id_range(1);
+#endif /* CONFIG_TRACEPOINTS */
+
+ /* Should already be checked in landlock_create_ruleset(). */
+ if (fs_access_mask) {
+ const access_mask_t mask = fs_access_mask &
+ LANDLOCK_MASK_ACCESS_FS;
+
+ WARN_ON_ONCE(fs_access_mask != mask);
+ new_ruleset->handled_masks.fs |= mask;
+ }
+ if (net_access_mask) {
+ const access_mask_t mask = net_access_mask &
+ LANDLOCK_MASK_ACCESS_NET;
+
+ WARN_ON_ONCE(net_access_mask != mask);
+ new_ruleset->handled_masks.net |= mask;
+ }
+ if (scope_mask) {
+ const access_mask_t mask = scope_mask & LANDLOCK_MASK_SCOPE;
+
+ WARN_ON_ONCE(scope_mask != mask);
+ new_ruleset->handled_masks.scope |= mask;
+ }
+ return new_ruleset;
+}
+
+static void build_check_rule(void)
+{
+ const struct landlock_rule rule = {
+ .num_layers = ~0,
+ };
+
+ /*
+ * Checks that .num_layers is large enough for at least
+ * LANDLOCK_MAX_NUM_LAYERS layers.
+ */
+ BUILD_BUG_ON(rule.num_layers < LANDLOCK_MAX_NUM_LAYERS);
+}
+
+static bool is_object_pointer(const enum landlock_key_type key_type)
+{
+ switch (key_type) {
+ case LANDLOCK_KEY_INODE:
+ return true;
+
+#if IS_ENABLED(CONFIG_INET)
+ case LANDLOCK_KEY_NET_PORT:
+ return false;
+#endif /* IS_ENABLED(CONFIG_INET) */
+
+ default:
+ WARN_ON_ONCE(1);
+ return false;
+ }
+}
+
+static struct landlock_rule *
+create_rule(const struct landlock_id id,
+ const struct landlock_layer (*layers)[], const u32 num_layers,
+ const struct landlock_layer *const new_layer)
+{
+ struct landlock_rule *new_rule;
+ u32 new_num_layers;
+
+ build_check_rule();
+ if (new_layer) {
+ /* Should already be checked by landlock_merge_ruleset(). */
+ if (WARN_ON_ONCE(num_layers >= LANDLOCK_MAX_NUM_LAYERS))
+ return ERR_PTR(-E2BIG);
+ new_num_layers = num_layers + 1;
+ } else {
+ new_num_layers = num_layers;
+ }
+ new_rule = kzalloc_flex(*new_rule, layers, new_num_layers,
+ GFP_KERNEL_ACCOUNT);
+ if (!new_rule)
+ return ERR_PTR(-ENOMEM);
+ RB_CLEAR_NODE(&new_rule->node);
+ if (is_object_pointer(id.type)) {
+ /* This should have been caught by landlock_store_rule(). */
+ WARN_ON_ONCE(!id.key.object);
+ landlock_get_object(id.key.object);
+ }
+
+ new_rule->key = id.key;
+ new_rule->num_layers = new_num_layers;
+ /* Copies the original layer stack. */
+ memcpy(new_rule->layers, layers,
+ flex_array_size(new_rule, layers, num_layers));
+ if (new_layer)
+ /* Adds a copy of @new_layer on the layer stack. */
+ new_rule->layers[new_rule->num_layers - 1] = *new_layer;
+ return new_rule;
+}
+
+static void free_rule(struct landlock_rule *const rule,
+ const enum landlock_key_type key_type)
+{
+ might_sleep();
+ if (!rule)
+ return;
+ if (is_object_pointer(key_type))
+ landlock_put_object(rule->key.object);
+ kfree(rule);
+}
+
+static void build_check_ruleset(void)
+{
+ const struct landlock_rules rules = {
+ .num_rules = ~0,
+ };
+
+ BUILD_BUG_ON(rules.num_rules < LANDLOCK_MAX_NUM_RULES);
+}
+
+/**
+ * landlock_store_rule - Create and insert a rule into the rule storage
+ *
+ * @rules: The rule storage to be updated. The caller is responsible for
+ * any required locking. For rulesets, this means holding
+ * &landlock_ruleset.lock. For domains under construction, no lock is
+ * needed because the domain is not yet visible to other tasks.
+ * @id: The ID to build the new rule with. The underlying kernel object, if
+ * any, must be held by the caller.
+ * @layers: One or multiple layers to be copied into the new rule.
+ * @num_layers: The number of @layers entries.
+ *
+ * When user space requests to add a new rule to a ruleset, @layers only
+ * contains one entry and this entry is not assigned to any level. In this
+ * case, the new rule will extend @rules, similarly to a boolean OR between
+ * access rights.
+ *
+ * When merging a ruleset in a domain, or copying a domain, @layers will be
+ * added to @rules as new constraints, similarly to a boolean AND between access
+ * rights.
+ *
+ * Return: 0 on success, -errno on failure.
+ */
+int landlock_store_rule(struct landlock_rules *const rules,
+ const struct landlock_id id,
+ const struct landlock_layer (*layers)[],
+ const size_t num_layers)
+{
+ struct rb_node **walker_node;
+ struct rb_node *parent_node = NULL;
+ struct landlock_rule *new_rule;
+ struct rb_root *root;
+
+ might_sleep();
+ if (WARN_ON_ONCE(!layers))
+ return -ENOENT;
+
+ if (is_object_pointer(id.type) && WARN_ON_ONCE(!id.key.object))
+ return -ENOENT;
+
+ root = landlock_get_rule_root(rules, id.type);
+ if (IS_ERR(root))
+ return PTR_ERR(root);
+
+ walker_node = &root->rb_node;
+ while (*walker_node) {
+ struct landlock_rule *const this =
+ rb_entry(*walker_node, struct landlock_rule, node);
+
+ if (this->key.data != id.key.data) {
+ parent_node = *walker_node;
+ if (this->key.data < id.key.data)
+ walker_node = &((*walker_node)->rb_right);
+ else
+ walker_node = &((*walker_node)->rb_left);
+ continue;
+ }
+
+ /* Only a single-level layer should match an existing rule. */
+ if (WARN_ON_ONCE(num_layers != 1))
+ return -EINVAL;
+
+ /* If there is a matching rule, updates it. */
+ if ((*layers)[0].level == 0) {
+ /*
+ * Extends access rights when the request comes from
+ * landlock_add_rule(2), i.e. @rules is not a domain.
+ */
+ if (WARN_ON_ONCE(this->num_layers != 1))
+ return -EINVAL;
+ if (WARN_ON_ONCE(this->layers[0].level != 0))
+ return -EINVAL;
+ this->layers[0].access |= (*layers)[0].access;
+ this->layers[0].flags.quiet |= (*layers)[0].flags.quiet;
+ return 0;
+ }
+
+ if (WARN_ON_ONCE(this->layers[0].level == 0))
+ return -EINVAL;
+
+ /*
+ * Intersects access rights when it is a merge between a
+ * ruleset and a domain.
+ */
+ new_rule = create_rule(id, &this->layers, this->num_layers,
+ &(*layers)[0]);
+ if (IS_ERR(new_rule))
+ return PTR_ERR(new_rule);
+ rb_replace_node(&this->node, &new_rule->node, root);
+ free_rule(this, id.type);
+ return 0;
+ }
+
+ /* There is no match for @id. */
+ build_check_ruleset();
+ if (rules->num_rules >= LANDLOCK_MAX_NUM_RULES)
+ return -E2BIG;
+ new_rule = create_rule(id, layers, num_layers, NULL);
+ if (IS_ERR(new_rule))
+ return PTR_ERR(new_rule);
+ rb_link_node(&new_rule->node, parent_node, walker_node);
+ rb_insert_color(&new_rule->node, root);
+ rules->num_rules++;
+ return 0;
+}
+
+static void build_check_layer(void)
+{
+ const struct landlock_layer layer = {
+ .level = ~0,
+ .access = ~0,
+ };
+
+ /*
+ * Checks that .level and .access are large enough to contain their expected
+ * maximum values.
+ */
+ BUILD_BUG_ON(layer.level < LANDLOCK_MAX_NUM_LAYERS);
+ BUILD_BUG_ON(layer.access < LANDLOCK_MASK_ACCESS_FS);
+}
+
+/* @ruleset must be locked by the caller. */
+int landlock_insert_rule(struct landlock_ruleset *const ruleset,
+ const struct landlock_id id,
+ const access_mask_t access, const u32 flags)
+{
+ struct landlock_layer layers[] = { {
+ .access = access,
+ /*
+ * When @level is zero, landlock_store_rule() extends @ruleset.
+ */
+ .level = 0,
+ .flags = {
+ .quiet = !!(flags & LANDLOCK_ADD_RULE_QUIET),
+ },
+ } };
+ int err;
+
+ build_check_layer();
+ lockdep_assert_held(&ruleset->lock);
+ err = landlock_store_rule(&ruleset->rules, id, &layers,
+ ARRAY_SIZE(layers));
+
+#ifdef CONFIG_TRACEPOINTS
+ if (!err)
+ ruleset->version++;
+#endif /* CONFIG_TRACEPOINTS */
+
+ return err;
+}
+
+void landlock_free_rules(struct landlock_rules *const rules)
+{
+ struct landlock_rule *freeme, *next;
+
+ might_sleep();
+ rbtree_postorder_for_each_entry_safe(freeme, next, &rules->root_inode,
+ node)
+ free_rule(freeme, LANDLOCK_KEY_INODE);
+
+#if IS_ENABLED(CONFIG_INET)
+ rbtree_postorder_for_each_entry_safe(freeme, next,
+ &rules->root_net_port, node)
+ free_rule(freeme, LANDLOCK_KEY_NET_PORT);
+#endif /* IS_ENABLED(CONFIG_INET) */
+}
+
+static void free_ruleset(struct landlock_ruleset *const ruleset)
+{
+ might_sleep();
+ trace_landlock_free_ruleset(ruleset);
+ landlock_free_rules(&ruleset->rules);
+ kfree(ruleset);
+}
+
+void landlock_put_ruleset(struct landlock_ruleset *const ruleset)
+{
+ might_sleep();
+ if (ruleset && refcount_dec_and_test(&ruleset->usage))
+ free_ruleset(ruleset);
+}