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
  ...

1 files changed, 587 insertions, 0 deletions

diff --git a/security/landlock/log.c b/security/landlock/log.c
new file mode 100644
index 000000000..a8578a6f2
--- /dev/null
+++ b/security/landlock/log.c
@@ -0,0 +1,587 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Landlock - Log helpers
+ *
+ * Copyright © 2023-2025 Microsoft Corporation
+ * Copyright © 2026 Cloudflare, Inc.
+ */
+
+#include <kunit/test.h>
+#include <linux/bitops.h>
+#include <uapi/linux/landlock.h>
+
+#include "access.h"
+#include "audit.h"
+#include "common.h"
+#include "cred.h"
+#include "domain.h"
+#include "limits.h"
+#include "log.h"
+#include "ruleset.h"
+#include "trace.h"
+
+static struct landlock_hierarchy *
+get_hierarchy(const struct landlock_domain *const domain, const size_t layer)
+{
+	struct landlock_hierarchy *hierarchy = domain->hierarchy;
+	ssize_t i;
+
+	if (WARN_ON_ONCE(layer >= domain->num_layers))
+		return hierarchy;
+
+	for (i = domain->num_layers - 1; i > layer; i--) {
+		if (WARN_ON_ONCE(!hierarchy->parent))
+			break;
+
+		hierarchy = hierarchy->parent;
+	}
+
+	return hierarchy;
+}
+
+#ifdef CONFIG_SECURITY_LANDLOCK_KUNIT_TEST
+
+static void test_get_hierarchy(struct kunit *const test)
+{
+	struct landlock_hierarchy dom0_hierarchy = {
+		.id = 10,
+	};
+	struct landlock_hierarchy dom1_hierarchy = {
+		.parent = &dom0_hierarchy,
+		.id = 20,
+	};
+	struct landlock_hierarchy dom2_hierarchy = {
+		.parent = &dom1_hierarchy,
+		.id = 30,
+	};
+	struct landlock_domain dom2 = {
+		.hierarchy = &dom2_hierarchy,
+		.num_layers = 3,
+	};
+
+	KUNIT_EXPECT_EQ(test, 10, get_hierarchy(&dom2, 0)->id);
+	KUNIT_EXPECT_EQ(test, 20, get_hierarchy(&dom2, 1)->id);
+	KUNIT_EXPECT_EQ(test, 30, get_hierarchy(&dom2, 2)->id);
+	/* KUNIT_EXPECT_EQ(test, 30, get_hierarchy(&dom2, -1)->id); */
+}
+
+#endif /* CONFIG_SECURITY_LANDLOCK_KUNIT_TEST */
+
+/* Get the youngest layer that denied the access_request. */
+static size_t get_denied_layer(const struct landlock_domain *const domain,
+			       access_mask_t *const access_request,
+			       const struct layer_masks *masks)
+{
+	for (ssize_t i = ARRAY_SIZE(masks->layers) - 1; i >= 0; i--) {
+		if (masks->layers[i].access & *access_request) {
+			*access_request &= masks->layers[i].access;
+			return i;
+		}
+	}
+
+	/* Not found - fall back to default values */
+	*access_request = 0;
+	return domain->num_layers - 1;
+}
+
+#ifdef CONFIG_SECURITY_LANDLOCK_KUNIT_TEST
+
+static void test_get_denied_layer(struct kunit *const test)
+{
+	const struct landlock_domain dom = {
+		.num_layers = 5,
+	};
+	const struct layer_masks masks = {
+		.layers[0].access = LANDLOCK_ACCESS_FS_EXECUTE |
+				    LANDLOCK_ACCESS_FS_READ_DIR,
+		.layers[1].access = LANDLOCK_ACCESS_FS_READ_FILE |
+				    LANDLOCK_ACCESS_FS_READ_DIR,
+		.layers[2].access = LANDLOCK_ACCESS_FS_REMOVE_DIR,
+	};
+	access_mask_t access;
+
+	access = LANDLOCK_ACCESS_FS_EXECUTE;
+	KUNIT_EXPECT_EQ(test, 0, get_denied_layer(&dom, &access, &masks));
+	KUNIT_EXPECT_EQ(test, access, LANDLOCK_ACCESS_FS_EXECUTE);
+
+	access = LANDLOCK_ACCESS_FS_READ_FILE;
+	KUNIT_EXPECT_EQ(test, 1, get_denied_layer(&dom, &access, &masks));
+	KUNIT_EXPECT_EQ(test, access, LANDLOCK_ACCESS_FS_READ_FILE);
+
+	access = LANDLOCK_ACCESS_FS_READ_DIR;
+	KUNIT_EXPECT_EQ(test, 1, get_denied_layer(&dom, &access, &masks));
+	KUNIT_EXPECT_EQ(test, access, LANDLOCK_ACCESS_FS_READ_DIR);
+
+	access = LANDLOCK_ACCESS_FS_READ_FILE | LANDLOCK_ACCESS_FS_READ_DIR;
+	KUNIT_EXPECT_EQ(test, 1, get_denied_layer(&dom, &access, &masks));
+	KUNIT_EXPECT_EQ(test, access,
+			LANDLOCK_ACCESS_FS_READ_FILE |
+				LANDLOCK_ACCESS_FS_READ_DIR);
+
+	access = LANDLOCK_ACCESS_FS_EXECUTE | LANDLOCK_ACCESS_FS_READ_DIR;
+	KUNIT_EXPECT_EQ(test, 1, get_denied_layer(&dom, &access, &masks));
+	KUNIT_EXPECT_EQ(test, access, LANDLOCK_ACCESS_FS_READ_DIR);
+
+	access = LANDLOCK_ACCESS_FS_WRITE_FILE;
+	KUNIT_EXPECT_EQ(test, 4, get_denied_layer(&dom, &access, &masks));
+	KUNIT_EXPECT_EQ(test, access, 0);
+}
+
+#endif /* CONFIG_SECURITY_LANDLOCK_KUNIT_TEST */
+
+static size_t
+get_layer_from_deny_masks(access_mask_t *const access_request,
+			  const access_mask_t all_existing_optional_access,
+			  const deny_masks_t deny_masks,
+			  optional_access_t quiet_optional_accesses,
+			  bool *quiet)
+{
+	const unsigned long access_opt = all_existing_optional_access;
+	const unsigned long access_req = *access_request;
+	access_mask_t missing = 0;
+	size_t youngest_layer = 0;
+	size_t access_index = 0;
+	unsigned long access_bit;
+	bool should_quiet = false;
+
+	/* This will require change with new object types. */
+	WARN_ON_ONCE(access_opt != _LANDLOCK_ACCESS_FS_OPTIONAL);
+
+	for_each_set_bit(access_bit, &access_opt,
+			 BITS_PER_TYPE(access_mask_t)) {
+		if (access_req & BIT(access_bit)) {
+			const size_t layer =
+				(deny_masks >>
+				 (access_index *
+				  HWEIGHT(LANDLOCK_MAX_NUM_LAYERS - 1))) &
+				(LANDLOCK_MAX_NUM_LAYERS - 1);
+			const bool layer_has_quiet =
+				!!(quiet_optional_accesses & BIT(access_index));
+
+			if (layer > youngest_layer) {
+				youngest_layer = layer;
+				missing = BIT(access_bit);
+				should_quiet = layer_has_quiet;
+			} else if (layer == youngest_layer) {
+				missing |= BIT(access_bit);
+				/*
+				 * Whether the layer has rules with quiet flag
+				 * covering the file accessed does not depend on
+				 * the access, and so the following
+				 * WARN_ON_ONCE() should not fail.
+				 */
+				WARN_ON_ONCE(should_quiet && !layer_has_quiet);
+				should_quiet = layer_has_quiet;
+			}
+		}
+		access_index++;
+	}
+
+	*access_request = missing;
+	*quiet = should_quiet;
+	return youngest_layer;
+}
+
+#ifdef CONFIG_SECURITY_LANDLOCK_KUNIT_TEST
+
+static void test_get_layer_from_deny_masks(struct kunit *const test)
+{
+	deny_masks_t deny_mask;
+	access_mask_t access;
+	optional_access_t quiet_optional_accesses;
+	bool quiet;
+
+	/* truncate:0 ioctl_dev:2 */
+	deny_mask = 0x20;
+	quiet_optional_accesses = 0;
+
+	access = LANDLOCK_ACCESS_FS_TRUNCATE;
+	KUNIT_EXPECT_EQ(test, 0,
+			get_layer_from_deny_masks(
+				&access, _LANDLOCK_ACCESS_FS_OPTIONAL,
+				deny_mask, quiet_optional_accesses, &quiet));
+	KUNIT_EXPECT_EQ(test, access, LANDLOCK_ACCESS_FS_TRUNCATE);
+	KUNIT_EXPECT_EQ(test, quiet, false);
+
+	access = LANDLOCK_ACCESS_FS_IOCTL_DEV;
+	KUNIT_EXPECT_EQ(test, 2,
+			get_layer_from_deny_masks(
+				&access, _LANDLOCK_ACCESS_FS_OPTIONAL,
+				deny_mask, quiet_optional_accesses, &quiet));
+	KUNIT_EXPECT_EQ(test, access, LANDLOCK_ACCESS_FS_IOCTL_DEV);
+	KUNIT_EXPECT_EQ(test, quiet, false);
+
+	access = LANDLOCK_ACCESS_FS_TRUNCATE | LANDLOCK_ACCESS_FS_IOCTL_DEV;
+	KUNIT_EXPECT_EQ(test, 2,
+			get_layer_from_deny_masks(
+				&access, _LANDLOCK_ACCESS_FS_OPTIONAL,
+				deny_mask, quiet_optional_accesses, &quiet));
+	KUNIT_EXPECT_EQ(test, access, LANDLOCK_ACCESS_FS_IOCTL_DEV);
+	KUNIT_EXPECT_EQ(test, quiet, false);
+
+	/* layer denying truncate: quiet, ioctl: not quiet */
+	quiet_optional_accesses = 0b01;
+
+	access = LANDLOCK_ACCESS_FS_TRUNCATE;
+	KUNIT_EXPECT_EQ(test, 0,
+			get_layer_from_deny_masks(
+				&access, _LANDLOCK_ACCESS_FS_OPTIONAL,
+				deny_mask, quiet_optional_accesses, &quiet));
+	KUNIT_EXPECT_EQ(test, access, LANDLOCK_ACCESS_FS_TRUNCATE);
+	KUNIT_EXPECT_EQ(test, quiet, true);
+
+	access = LANDLOCK_ACCESS_FS_IOCTL_DEV;
+	KUNIT_EXPECT_EQ(test, 2,
+			get_layer_from_deny_masks(
+				&access, _LANDLOCK_ACCESS_FS_OPTIONAL,
+				deny_mask, quiet_optional_accesses, &quiet));
+	KUNIT_EXPECT_EQ(test, access, LANDLOCK_ACCESS_FS_IOCTL_DEV);
+	KUNIT_EXPECT_EQ(test, quiet, false);
+
+	access = LANDLOCK_ACCESS_FS_TRUNCATE | LANDLOCK_ACCESS_FS_IOCTL_DEV;
+	KUNIT_EXPECT_EQ(test, 2,
+			get_layer_from_deny_masks(
+				&access, _LANDLOCK_ACCESS_FS_OPTIONAL,
+				deny_mask, quiet_optional_accesses, &quiet));
+	KUNIT_EXPECT_EQ(test, access, LANDLOCK_ACCESS_FS_IOCTL_DEV);
+	KUNIT_EXPECT_EQ(test, quiet, false);
+
+	/* Reverse order - truncate:2 ioctl_dev:0 */
+	deny_mask = 0x02;
+	quiet_optional_accesses = 0;
+
+	access = LANDLOCK_ACCESS_FS_TRUNCATE;
+	KUNIT_EXPECT_EQ(test, 2,
+			get_layer_from_deny_masks(
+				&access, _LANDLOCK_ACCESS_FS_OPTIONAL,
+				deny_mask, quiet_optional_accesses, &quiet));
+	KUNIT_EXPECT_EQ(test, access, LANDLOCK_ACCESS_FS_TRUNCATE);
+	KUNIT_EXPECT_EQ(test, quiet, false);
+
+	access = LANDLOCK_ACCESS_FS_IOCTL_DEV;
+	KUNIT_EXPECT_EQ(test, 0,
+			get_layer_from_deny_masks(
+				&access, _LANDLOCK_ACCESS_FS_OPTIONAL,
+				deny_mask, quiet_optional_accesses, &quiet));
+	KUNIT_EXPECT_EQ(test, access, LANDLOCK_ACCESS_FS_IOCTL_DEV);
+	KUNIT_EXPECT_EQ(test, quiet, false);
+
+	access = LANDLOCK_ACCESS_FS_TRUNCATE | LANDLOCK_ACCESS_FS_IOCTL_DEV;
+	KUNIT_EXPECT_EQ(test, 2,
+			get_layer_from_deny_masks(
+				&access, _LANDLOCK_ACCESS_FS_OPTIONAL,
+				deny_mask, quiet_optional_accesses, &quiet));
+	KUNIT_EXPECT_EQ(test, access, LANDLOCK_ACCESS_FS_TRUNCATE);
+	KUNIT_EXPECT_EQ(test, quiet, false);
+
+	/* layer denying truncate: quiet, ioctl: not quiet */
+	quiet_optional_accesses = 0b01;
+
+	access = LANDLOCK_ACCESS_FS_TRUNCATE;
+	KUNIT_EXPECT_EQ(test, 2,
+			get_layer_from_deny_masks(
+				&access, _LANDLOCK_ACCESS_FS_OPTIONAL,
+				deny_mask, quiet_optional_accesses, &quiet));
+	KUNIT_EXPECT_EQ(test, access, LANDLOCK_ACCESS_FS_TRUNCATE);
+	KUNIT_EXPECT_EQ(test, quiet, true);
+
+	access = LANDLOCK_ACCESS_FS_IOCTL_DEV;
+	KUNIT_EXPECT_EQ(test, 0,
+			get_layer_from_deny_masks(
+				&access, _LANDLOCK_ACCESS_FS_OPTIONAL,
+				deny_mask, quiet_optional_accesses, &quiet));
+	KUNIT_EXPECT_EQ(test, access, LANDLOCK_ACCESS_FS_IOCTL_DEV);
+	KUNIT_EXPECT_EQ(test, quiet, false);
+
+	access = LANDLOCK_ACCESS_FS_TRUNCATE | LANDLOCK_ACCESS_FS_IOCTL_DEV;
+	KUNIT_EXPECT_EQ(test, 2,
+			get_layer_from_deny_masks(
+				&access, _LANDLOCK_ACCESS_FS_OPTIONAL,
+				deny_mask, quiet_optional_accesses, &quiet));
+	KUNIT_EXPECT_EQ(test, access, LANDLOCK_ACCESS_FS_TRUNCATE);
+	KUNIT_EXPECT_EQ(test, quiet, true);
+
+	/* layer denying truncate: not quiet, ioctl: quiet */
+	quiet_optional_accesses = 0b10;
+
+	access = LANDLOCK_ACCESS_FS_TRUNCATE;
+	KUNIT_EXPECT_EQ(test, 2,
+			get_layer_from_deny_masks(
+				&access, _LANDLOCK_ACCESS_FS_OPTIONAL,
+				deny_mask, quiet_optional_accesses, &quiet));
+	KUNIT_EXPECT_EQ(test, access, LANDLOCK_ACCESS_FS_TRUNCATE);
+	KUNIT_EXPECT_EQ(test, quiet, false);
+
+	access = LANDLOCK_ACCESS_FS_IOCTL_DEV;
+	KUNIT_EXPECT_EQ(test, 0,
+			get_layer_from_deny_masks(
+				&access, _LANDLOCK_ACCESS_FS_OPTIONAL,
+				deny_mask, quiet_optional_accesses, &quiet));
+	KUNIT_EXPECT_EQ(test, access, LANDLOCK_ACCESS_FS_IOCTL_DEV);
+	KUNIT_EXPECT_EQ(test, quiet, true);
+
+	access = LANDLOCK_ACCESS_FS_TRUNCATE | LANDLOCK_ACCESS_FS_IOCTL_DEV;
+	KUNIT_EXPECT_EQ(test, 2,
+			get_layer_from_deny_masks(
+				&access, _LANDLOCK_ACCESS_FS_OPTIONAL,
+				deny_mask, quiet_optional_accesses, &quiet));
+	KUNIT_EXPECT_EQ(test, access, LANDLOCK_ACCESS_FS_TRUNCATE);
+	KUNIT_EXPECT_EQ(test, quiet, false);
+
+	/* truncate:15 ioctl_dev:15 */
+	deny_mask = 0xff;
+	quiet_optional_accesses = 0;
+
+	access = LANDLOCK_ACCESS_FS_TRUNCATE;
+	KUNIT_EXPECT_EQ(test, 15,
+			get_layer_from_deny_masks(
+				&access, _LANDLOCK_ACCESS_FS_OPTIONAL,
+				deny_mask, quiet_optional_accesses, &quiet));
+	KUNIT_EXPECT_EQ(test, access, LANDLOCK_ACCESS_FS_TRUNCATE);
+	KUNIT_EXPECT_EQ(test, quiet, false);
+
+	access = LANDLOCK_ACCESS_FS_TRUNCATE | LANDLOCK_ACCESS_FS_IOCTL_DEV;
+	KUNIT_EXPECT_EQ(test, 15,
+			get_layer_from_deny_masks(
+				&access, _LANDLOCK_ACCESS_FS_OPTIONAL,
+				deny_mask, quiet_optional_accesses, &quiet));
+	KUNIT_EXPECT_EQ(test, access,
+			LANDLOCK_ACCESS_FS_TRUNCATE |
+				LANDLOCK_ACCESS_FS_IOCTL_DEV);
+	KUNIT_EXPECT_EQ(test, quiet, false);
+
+	/* Both quiet (same layer so quietness must be the same) */
+	quiet_optional_accesses = 0b11;
+
+	access = LANDLOCK_ACCESS_FS_TRUNCATE;
+	KUNIT_EXPECT_EQ(test, 15,
+			get_layer_from_deny_masks(
+				&access, _LANDLOCK_ACCESS_FS_OPTIONAL,
+				deny_mask, quiet_optional_accesses, &quiet));
+	KUNIT_EXPECT_EQ(test, access, LANDLOCK_ACCESS_FS_TRUNCATE);
+	KUNIT_EXPECT_EQ(test, quiet, true);
+
+	access = LANDLOCK_ACCESS_FS_TRUNCATE | LANDLOCK_ACCESS_FS_IOCTL_DEV;
+	KUNIT_EXPECT_EQ(test, 15,
+			get_layer_from_deny_masks(
+				&access, _LANDLOCK_ACCESS_FS_OPTIONAL,
+				deny_mask, quiet_optional_accesses, &quiet));
+	KUNIT_EXPECT_EQ(test, access,
+			LANDLOCK_ACCESS_FS_TRUNCATE |
+				LANDLOCK_ACCESS_FS_IOCTL_DEV);
+	KUNIT_EXPECT_EQ(test, quiet, true);
+}
+
+#endif /* CONFIG_SECURITY_LANDLOCK_KUNIT_TEST */
+
+static bool is_valid_request(const struct landlock_request *const request)
+{
+	if (WARN_ON_ONCE(request->layer_plus_one > LANDLOCK_MAX_NUM_LAYERS))
+		return false;
+
+	if (WARN_ON_ONCE(!(!!request->layer_plus_one ^ !!request->access)))
+		return false;
+
+	if (request->access) {
+		if (WARN_ON_ONCE(!(!!request->layer_masks ^
+				   !!request->all_existing_optional_access)))
+			return false;
+	} else {
+		if (WARN_ON_ONCE(request->layer_masks ||
+				 request->all_existing_optional_access))
+			return false;
+	}
+
+	if (request->deny_masks) {
+		if (WARN_ON_ONCE(!request->all_existing_optional_access))
+			return false;
+		static_assert(sizeof(request->all_existing_optional_access) ==
+			      sizeof(u32));
+		if (WARN_ON_ONCE(
+			    request->quiet_optional_accesses >=
+			    BIT(hweight32(
+				    request->all_existing_optional_access))))
+			return false;
+	}
+
+	return true;
+}
+
+static access_mask_t
+pick_access_mask_for_request_type(const enum landlock_request_type type,
+				  const struct access_masks access_masks)
+{
+	switch (type) {
+	case LANDLOCK_REQUEST_FS_ACCESS:
+		return access_masks.fs;
+	case LANDLOCK_REQUEST_NET_ACCESS:
+		return access_masks.net;
+	default:
+		WARN_ONCE(1, "Invalid request type %d passed to %s", type,
+			  __func__);
+		return 0;
+	}
+}
+
+/*
+ * Whether a quiet rule silences the denial: the rule must cover the whole
+ * denied access in the layer that denied it (a quiet rule in a non-denying
+ * layer does not suppress the denial).
+ */
+static bool
+is_denial_quieted(const struct landlock_request *const request,
+		  const struct landlock_hierarchy *const youngest_denied,
+		  const access_mask_t missing, const bool object_quiet_flag)
+{
+	if (object_quiet_flag) {
+		const access_mask_t quiet_mask =
+			pick_access_mask_for_request_type(
+				request->type, youngest_denied->quiet_masks);
+
+		return (quiet_mask & missing) == missing;
+	}
+
+	/*
+	 * Either the object is not quiet, or this is a scope request.  We check
+	 * request->type to distinguish between the two cases.
+	 */
+	switch (request->type) {
+	case LANDLOCK_REQUEST_SCOPE_SIGNAL:
+		return !!(youngest_denied->quiet_masks.scope &
+			  LANDLOCK_SCOPE_SIGNAL);
+	case LANDLOCK_REQUEST_SCOPE_ABSTRACT_UNIX_SOCKET:
+		return !!(youngest_denied->quiet_masks.scope &
+			  LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET);
+	/*
+	 * Leave LANDLOCK_REQUEST_PTRACE and LANDLOCK_REQUEST_FS_CHANGE_TOPOLOGY
+	 * unhandled for now - they are never quiet.
+	 */
+	default:
+		return false;
+	}
+}
+
+/*
+ * Computes whether a denial from youngest_denied is selected for logging by the
+ * domain's policy: its logging must not be disabled (by both per-execution
+ * flags being off, or by an ancestor's
+ * LANDLOCK_RESTRICT_SELF_LOG_SUBDOMAINS_OFF), the per-execution flag matching
+ * same_exec must be set, and no quiet rule may cover the denied access.
+ * landlock_log_denial() computes this once and passes it to
+ * landlock_audit_denial(), which additionally requires audit_enabled.
+ */
+static bool
+is_denial_logged(const struct landlock_request *const request,
+		 const struct landlock_hierarchy *const youngest_denied,
+		 const access_mask_t missing, const bool same_exec,
+		 const bool object_quiet_flag)
+{
+	if (READ_ONCE(youngest_denied->log_status) == LANDLOCK_LOG_DISABLED)
+		return false;
+
+	if (!(same_exec ? youngest_denied->log_same_exec :
+			  youngest_denied->log_new_exec))
+		return false;
+
+	return !is_denial_quieted(request, youngest_denied, missing,
+				  object_quiet_flag);
+}
+
+/**
+ * landlock_log_denial - Log a denied access
+ *
+ * @subject: The Landlock subject's credential denying an action.
+ * @request: Detail of the user space request.
+ */
+void landlock_log_denial(const struct landlock_cred_security *const subject,
+			 const struct landlock_request *const request)
+{
+	struct landlock_hierarchy *youngest_denied;
+	size_t youngest_layer;
+	access_mask_t missing;
+	bool object_quiet_flag = false;
+
+	if (WARN_ON_ONCE(!subject || !subject->domain ||
+			 !subject->domain->hierarchy || !request))
+		return;
+
+	if (!is_valid_request(request))
+		return;
+
+	missing = request->access;
+	if (missing) {
+		/* Gets the nearest domain that denies the request. */
+		if (request->layer_masks) {
+			youngest_layer = get_denied_layer(subject->domain,
+							  &missing,
+							  request->layer_masks);
+			object_quiet_flag =
+				request->layer_masks->layers[youngest_layer]
+					.quiet;
+		} else {
+			youngest_layer = get_layer_from_deny_masks(
+				&missing, _LANDLOCK_ACCESS_FS_OPTIONAL,
+				request->deny_masks,
+				request->quiet_optional_accesses,
+				&object_quiet_flag);
+		}
+		youngest_denied =
+			get_hierarchy(subject->domain, youngest_layer);
+	} else {
+		youngest_layer = request->layer_plus_one - 1;
+		youngest_denied =
+			get_hierarchy(subject->domain, youngest_layer);
+	}
+
+	const bool same_exec = !!(subject->domain_exec & BIT(youngest_layer));
+	const bool logged = is_denial_logged(request, youngest_denied, missing,
+					     same_exec, object_quiet_flag);
+
+	/*
+	 * Consistently keeps track of the number of denied access requests even
+	 * if audit is currently disabled, or if audit rules currently exclude
+	 * this record type, or if landlock_restrict_self(2)'s flags quiet logs.
+	 */
+	atomic64_inc(&youngest_denied->num_denials);
+
+	landlock_trace_denial(request, youngest_denied, missing, same_exec,
+			      logged);
+	landlock_audit_denial(request, youngest_denied, missing, logged);
+}
+
+/**
+ * landlock_log_free_domain - Log domain deallocation
+ *
+ * @hierarchy: The domain's hierarchy being deallocated.
+ *
+ * Called from landlock_put_domain_deferred() (via a work queue scheduled by
+ * hook_cred_free()) or directly from landlock_put_domain().
+ */
+void landlock_log_free_domain(const struct landlock_hierarchy *const hierarchy)
+{
+	if (WARN_ON_ONCE(!hierarchy))
+		return;
+
+	landlock_trace_free_domain(hierarchy);
+	landlock_audit_free_domain(hierarchy);
+}
+
+#ifdef CONFIG_SECURITY_LANDLOCK_KUNIT_TEST
+
+static struct kunit_case test_cases[] = {
+	/* clang-format off */
+	KUNIT_CASE(test_get_hierarchy),
+	KUNIT_CASE(test_get_denied_layer),
+	KUNIT_CASE(test_get_layer_from_deny_masks),
+	{}
+	/* clang-format on */
+};
+
+static struct kunit_suite test_suite = {
+	.name = "landlock_log",
+	.test_cases = test_cases,
+};
+
+kunit_test_suite(test_suite);
+
+#endif /* CONFIG_SECURITY_LANDLOCK_KUNIT_TEST */