diff --git a/include/linux/kfence.h b/include/linux/kfence.h
new file mode 100644
index 000000000000..8128ba7b5e90
--- /dev/null
+++ b/include/linux/kfence.h
@@ -0,0 +1,174 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef _LINUX_KFENCE_H
+#define _LINUX_KFENCE_H
+
+#include <linux/mm.h>
+#include <linux/percpu.h>
+#include <linux/static_key.h>
+#include <linux/types.h>
+
+#ifdef CONFIG_KFENCE
+
+/*
+ * We allocate an even number of pages, as it simplifies calculations to map
+ * address to metadata indices; effectively, the very first page serves as an
+ * extended guard page, but otherwise has no special purpose.
+ */
+#define KFENCE_POOL_SIZE ((CONFIG_KFENCE_NUM_OBJECTS + 1) * 2 * PAGE_SIZE)
+#ifdef CONFIG_HAVE_ARCH_KFENCE_STATIC_POOL
+extern char __kfence_pool[KFENCE_POOL_SIZE];
+#else
+extern char *__kfence_pool;
+#endif
+
+extern struct static_key_false kfence_allocation_key;
+
+/**
+ * is_kfence_address() - check if an address belongs to KFENCE pool
+ * @addr: address to check
+ *
+ * Return: true or false depending on whether the address is within the KFENCE
+ * object range.
+ *
+ * KFENCE objects live in a separate page range and are not to be intermixed
+ * with regular heap objects (e.g. KFENCE objects must never be added to the
+ * allocator freelists). Failing to do so may and will result in heap
+ * corruptions, therefore is_kfence_address() must be used to check whether
+ * an object requires specific handling.
+ */
+static __always_inline bool is_kfence_address(const void *addr)
+{
+	return unlikely((char *)addr >= __kfence_pool &&
+			(char *)addr < __kfence_pool + KFENCE_POOL_SIZE);
+}
+
+/**
+ * kfence_init() - perform KFENCE initialization at boot time
+ */
+void kfence_init(void);
+
+/**
+ * kfence_shutdown_cache() - handle shutdown_cache() for KFENCE objects
+ * @s: cache being shut down
+ *
+ * Return: true on success, false if any leftover objects persist.
+ *
+ * Before shutting down a cache, one must ensure there are no remaining objects
+ * allocated from it. KFENCE objects are not referenced from the cache, so
+ * kfence_shutdown_cache() takes care of them.
+ */
+bool __must_check kfence_shutdown_cache(struct kmem_cache *s);
+
+/*
+ * Allocate a KFENCE object. Allocators must not call this function directly,
+ * use kfence_alloc() instead.
+ */
+void *__kfence_alloc(struct kmem_cache *s, size_t size, gfp_t flags);
+
+/**
+ * kfence_alloc() - allocate a KFENCE object with a low probability
+ * @s:     struct kmem_cache with object requirements
+ * @size:  exact size of the object to allocate (can be less than @s->size
+ *         e.g. for kmalloc caches)
+ * @flags: GFP flags
+ *
+ * Return:
+ * * NULL     - must proceed with allocating as usual,
+ * * non-NULL - pointer to a KFENCE object.
+ *
+ * kfence_alloc() should be inserted into the heap allocation fast path,
+ * allowing it to transparently return KFENCE-allocated objects with a low
+ * probability using a static branch (the probability is controlled by the
+ * kfence.sample_interval boot parameter).
+ */
+static __always_inline void *kfence_alloc(struct kmem_cache *s, size_t size, gfp_t flags)
+{
+	return static_branch_unlikely(&kfence_allocation_key) ? __kfence_alloc(s, size, flags) :
+								      NULL;
+}
+
+/**
+ * kfence_ksize() - get actual amount of memory allocated for a KFENCE object
+ * @addr: pointer to a heap object
+ *
+ * Return:
+ * * 0     - not a KFENCE object, must call __ksize() instead,
+ * * non-0 - this many bytes can be accessed without causing a memory error.
+ *
+ * kfence_ksize() returns the number of bytes requested for a KFENCE object at
+ * allocation time. This number may be less than the object size of the
+ * corresponding struct kmem_cache.
+ */
+size_t kfence_ksize(const void *addr);
+
+/**
+ * kfence_object_start() - find the beginning of a KFENCE object
+ * @addr - address within a KFENCE-allocated object
+ *
+ * Return: address of the beginning of the object.
+ *
+ * SL[AU]B-allocated objects are laid out within a page one by one, so it is
+ * easy to calculate the beginning of an object given a pointer inside it and
+ * the object size. The same is not true for KFENCE, which places a single
+ * object at either end of the page. This helper function is used to find the
+ * beginning of a KFENCE-allocated object.
+ */
+void *kfence_object_start(const void *addr);
+
+/*
+ * Release a KFENCE-allocated object to KFENCE pool. Allocators must not call
+ * this function directly, use kfence_free() instead.
+ */
+void __kfence_free(void *addr);
+
+/**
+ * kfence_free() - try to release an arbitrary heap object to KFENCE pool
+ * @addr: object to be freed
+ *
+ * Return:
+ * * false - object doesn't belong to KFENCE pool and was ignored,
+ * * true  - object was released to KFENCE pool.
+ *
+ * Release a KFENCE object and mark it as freed. May be called on any object,
+ * even non-KFENCE objects, to simplify integration of the hooks into the
+ * allocator's free codepath. The allocator must check the return value to
+ * determine if it was a KFENCE object or not.
+ */
+static __always_inline __must_check bool kfence_free(void *addr)
+{
+	if (!is_kfence_address(addr))
+		return false;
+	__kfence_free(addr);
+	return true;
+}
+
+/**
+ * kfence_handle_page_fault() - perform page fault handling for KFENCE pages
+ * @addr: faulting address
+ *
+ * Return:
+ * * false - address outside KFENCE pool,
+ * * true  - page fault handled by KFENCE, no additional handling required.
+ *
+ * A page fault inside KFENCE pool indicates a memory error, such as an
+ * out-of-bounds access, a use-after-free or an invalid memory access. In these
+ * cases KFENCE prints an error message and marks the offending page as
+ * present, so that the kernel can proceed.
+ */
+bool __must_check kfence_handle_page_fault(unsigned long addr);
+
+#else /* CONFIG_KFENCE */
+
+static inline bool is_kfence_address(const void *addr) { return false; }
+static inline void kfence_init(void) { }
+static inline bool __must_check kfence_shutdown_cache(struct kmem_cache *s) { return true; }
+static inline void *kfence_alloc(struct kmem_cache *s, size_t size, gfp_t flags) { return NULL; }
+static inline size_t kfence_ksize(const void *addr) { return 0; }
+static inline void *kfence_object_start(const void *addr) { return NULL; }
+static inline bool __must_check kfence_free(void *addr) { return false; }
+static inline bool __must_check kfence_handle_page_fault(unsigned long addr) { return false; }
+
+#endif
+
+#endif /* _LINUX_KFENCE_H */
diff --git a/init/main.c b/init/main.c
index ae78fb68d231..ec7de9dc1ed8 100644
--- a/init/main.c
+++ b/init/main.c
@@ -39,6 +39,7 @@
 #include <linux/security.h>
 #include <linux/smp.h>
 #include <linux/profile.h>
+#include <linux/kfence.h>
 #include <linux/rcupdate.h>
 #include <linux/moduleparam.h>
 #include <linux/kallsyms.h>
@@ -942,6 +943,7 @@ asmlinkage __visible void __init __no_sanitize_address start_kernel(void)
 	hrtimers_init();
 	softirq_init();
 	timekeeping_init();
+	kfence_init();
 
 	/*
 	 * For best initial stack canary entropy, prepare it after:
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index e068c3c7189a..d09c6a306532 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -880,6 +880,7 @@ config DEBUG_STACKOVERFLOW
 	  If in doubt, say "N".
 
 source "lib/Kconfig.kasan"
+source "lib/Kconfig.kfence"
 
 endmenu # "Memory Debugging"
 
diff --git a/lib/Kconfig.kfence b/lib/Kconfig.kfence
new file mode 100644
index 000000000000..4c2ea1c722de
--- /dev/null
+++ b/lib/Kconfig.kfence
@@ -0,0 +1,63 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+config HAVE_ARCH_KFENCE
+	bool
+
+config HAVE_ARCH_KFENCE_STATIC_POOL
+	bool
+	help
+	  If the architecture supports using the static pool.
+
+menuconfig KFENCE
+	bool "KFENCE: low-overhead sampling-based memory safety error detector"
+	depends on HAVE_ARCH_KFENCE && !KASAN && (SLAB || SLUB)
+	depends on JUMP_LABEL # To ensure performance, require jump labels
+	select STACKTRACE
+	help
+	  KFENCE is low-overhead sampling-based detector for heap out-of-bounds
+	  access, use-after-free, and invalid-free errors. KFENCE is designed
+	  to have negligible cost to permit enabling it in production
+	  environments.
+
+	  Note that, KFENCE is not a substitute for explicit testing with tools
+	  such as KASAN. KFENCE can detect a subset of bugs that KASAN can
+	  detect, albeit at very different performance profiles. If you can
+	  afford to use KASAN, continue using KASAN, for example in test
+	  environments. If your kernel targets production use, and cannot
+	  enable KASAN due to its cost, consider using KFENCE.
+
+if KFENCE
+
+config KFENCE_SAMPLE_INTERVAL
+	int "Default sample interval in milliseconds"
+	default 100
+	help
+	  The KFENCE sample interval determines the frequency with which heap
+	  allocations will be guarded by KFENCE. May be overridden via boot
+	  parameter "kfence.sample_interval".
+
+	  Set this to 0 to disable KFENCE by default, in which case only
+	  setting "kfence.sample_interval" to a non-zero value enables KFENCE.
+
+config KFENCE_NUM_OBJECTS
+	int "Number of guarded objects available"
+	default 255
+	range 1 16383
+	help
+	  The number of guarded objects available. For each KFENCE object, 2
+	  pages are required; with one containing the object and two adjacent
+	  ones used as guard pages.
+
+config KFENCE_STRESS_TEST_FAULTS
+	int "Stress testing of fault handling and error reporting"
+	default 0
+	depends on EXPERT
+	help
+	  The inverse probability with which to randomly protect KFENCE object
+	  pages, resulting in spurious use-after-frees. The main purpose of
+	  this option is to stress test KFENCE with concurrent error reports
+	  and allocations/frees. A value of 0 disables stress testing logic.
+
+	  The option is only to test KFENCE; set to 0 if you are unsure.
+
+endif # KFENCE
diff --git a/mm/Makefile b/mm/Makefile
index d5649f1c12c0..afdf1ae0900b 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -81,6 +81,7 @@ obj-$(CONFIG_PAGE_POISONING) += page_poison.o
 obj-$(CONFIG_SLAB) += slab.o
 obj-$(CONFIG_SLUB) += slub.o
 obj-$(CONFIG_KASAN)	+= kasan/
+obj-$(CONFIG_KFENCE) += kfence/
 obj-$(CONFIG_FAILSLAB) += failslab.o
 obj-$(CONFIG_MEMORY_HOTPLUG) += memory_hotplug.o
 obj-$(CONFIG_MEMTEST)		+= memtest.o
diff --git a/mm/kfence/Makefile b/mm/kfence/Makefile
new file mode 100644
index 000000000000..d991e9a349f0
--- /dev/null
+++ b/mm/kfence/Makefile
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0
+
+obj-$(CONFIG_KFENCE) := core.o report.o
diff --git a/mm/kfence/core.c b/mm/kfence/core.c
new file mode 100644
index 000000000000..938da1648304
--- /dev/null
+++ b/mm/kfence/core.c
@@ -0,0 +1,733 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#define pr_fmt(fmt) "kfence: " fmt
+
+#include <linux/atomic.h>
+#include <linux/bug.h>
+#include <linux/debugfs.h>
+#include <linux/kcsan-checks.h>
+#include <linux/kfence.h>
+#include <linux/list.h>
+#include <linux/lockdep.h>
+#include <linux/moduleparam.h>
+#include <linux/random.h>
+#include <linux/rcupdate.h>
+#include <linux/seq_file.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/string.h>
+
+#include <asm/kfence.h>
+
+#include "kfence.h"
+
+/* Disables KFENCE on the first warning assuming an irrecoverable error. */
+#define KFENCE_WARN_ON(cond)                                                   \
+	({                                                                     \
+		const bool __cond = WARN_ON(cond);                             \
+		if (unlikely(__cond))                                          \
+			WRITE_ONCE(kfence_enabled, false);                     \
+		__cond;                                                        \
+	})
+
+#ifndef CONFIG_KFENCE_STRESS_TEST_FAULTS /* Only defined with CONFIG_EXPERT. */
+#define CONFIG_KFENCE_STRESS_TEST_FAULTS 0
+#endif
+
+/* === Data ================================================================= */
+
+static unsigned long kfence_sample_interval __read_mostly = CONFIG_KFENCE_SAMPLE_INTERVAL;
+
+#ifdef MODULE_PARAM_PREFIX
+#undef MODULE_PARAM_PREFIX
+#endif
+#define MODULE_PARAM_PREFIX "kfence."
+module_param_named(sample_interval, kfence_sample_interval, ulong, 0600);
+
+static bool kfence_enabled __read_mostly;
+
+/*
+ * The pool of pages used for guard pages and objects. If supported, allocated
+ * statically, so that is_kfence_address() avoids a pointer load, and simply
+ * compares against a constant address. Assume that if KFENCE is compiled into
+ * the kernel, it is usually enabled, and the space is to be allocated one way
+ * or another.
+ */
+#ifdef CONFIG_HAVE_ARCH_KFENCE_STATIC_POOL
+char __kfence_pool[KFENCE_POOL_SIZE] __kfence_pool_attrs;
+#else
+char *__kfence_pool __read_mostly;
+#endif
+EXPORT_SYMBOL(__kfence_pool); /* Export for test modules. */
+
+/*
+ * Per-object metadata, with one-to-one mapping of object metadata to
+ * backing pages (in __kfence_pool).
+ */
+static_assert(CONFIG_KFENCE_NUM_OBJECTS > 0);
+struct kfence_metadata kfence_metadata[CONFIG_KFENCE_NUM_OBJECTS];
+
+/* Freelist with available objects. */
+static struct list_head kfence_freelist = LIST_HEAD_INIT(kfence_freelist);
+static DEFINE_RAW_SPINLOCK(kfence_freelist_lock); /* Lock protecting freelist. */
+
+/* The static key to set up a KFENCE allocation. */
+DEFINE_STATIC_KEY_FALSE(kfence_allocation_key);
+
+/* Gates the allocation, ensuring only one succeeds in a given period. */
+static atomic_t allocation_gate = ATOMIC_INIT(1);
+
+/* Wait queue to wake up allocation-gate timer task. */
+static DECLARE_WAIT_QUEUE_HEAD(allocation_wait);
+
+/* Statistics counters for debugfs. */
+enum kfence_counter_id {
+	KFENCE_COUNTER_ALLOCATED,
+	KFENCE_COUNTER_ALLOCS,
+	KFENCE_COUNTER_FREES,
+	KFENCE_COUNTER_BUGS,
+	KFENCE_COUNTER_COUNT,
+};
+static atomic_long_t counters[KFENCE_COUNTER_COUNT];
+static const char *const counter_names[] = {
+	[KFENCE_COUNTER_ALLOCATED]	= "currently allocated",
+	[KFENCE_COUNTER_ALLOCS]		= "total allocations",
+	[KFENCE_COUNTER_FREES]		= "total frees",
+	[KFENCE_COUNTER_BUGS]		= "total bugs",
+};
+static_assert(ARRAY_SIZE(counter_names) == KFENCE_COUNTER_COUNT);
+
+/* === Internals ============================================================ */
+
+static bool kfence_protect(unsigned long addr)
+{
+	return !KFENCE_WARN_ON(!kfence_protect_page(ALIGN_DOWN(addr, PAGE_SIZE), true));
+}
+
+static bool kfence_unprotect(unsigned long addr)
+{
+	return !KFENCE_WARN_ON(!kfence_protect_page(ALIGN_DOWN(addr, PAGE_SIZE), false));
+}
+
+static inline struct kfence_metadata *addr_to_metadata(unsigned long addr)
+{
+	long index;
+
+	/* The checks do not affect performance; only called from slow-paths. */
+
+	if (!is_kfence_address((void *)addr))
+		return NULL;
+
+	/*
+	 * May be an invalid index if called with an address at the edge of
+	 * __kfence_pool, in which case we would report an "invalid access"
+	 * error.
+	 */
+	index = (addr - (unsigned long)__kfence_pool) / (PAGE_SIZE * 2) - 1;
+	if (index < 0 || index >= CONFIG_KFENCE_NUM_OBJECTS)
+		return NULL;
+
+	return &kfence_metadata[index];
+}
+
+static inline unsigned long metadata_to_pageaddr(const struct kfence_metadata *meta)
+{
+	unsigned long offset = (meta - kfence_metadata + 1) * PAGE_SIZE * 2;
+	unsigned long pageaddr = (unsigned long)&__kfence_pool[offset];
+
+	/* The checks do not affect performance; only called from slow-paths. */
+
+	/* Only call with a pointer into kfence_metadata. */
+	if (KFENCE_WARN_ON(meta < kfence_metadata ||
+			   meta >= kfence_metadata + CONFIG_KFENCE_NUM_OBJECTS))
+		return 0;
+
+	/*
+	 * This metadata object only ever maps to 1 page; verify the calculation
+	 * happens and that the stored address was not corrupted.
+	 */
+	if (KFENCE_WARN_ON(ALIGN_DOWN(meta->addr, PAGE_SIZE) != pageaddr))
+		return 0;
+
+	return pageaddr;
+}
+
+/*
+ * Update the object's metadata state, including updating the alloc/free stacks
+ * depending on the state transition.
+ */
+static noinline void metadata_update_state(struct kfence_metadata *meta,
+					   enum kfence_object_state next)
+{
+	unsigned long *entries = next == KFENCE_OBJECT_FREED ? meta->free_stack : meta->alloc_stack;
+	/*
+	 * Skip over 1 (this) functions; noinline ensures we do not accidentally
+	 * skip over the caller by never inlining.
+	 */
+	const int nentries = stack_trace_save(entries, KFENCE_STACK_DEPTH, 1);
+
+	lockdep_assert_held(&meta->lock);
+
+	if (next == KFENCE_OBJECT_FREED)
+		meta->num_free_stack = nentries;
+	else
+		meta->num_alloc_stack = nentries;
+
+	/*
+	 * Pairs with READ_ONCE() in
+	 *	kfence_shutdown_cache(),
+	 *	kfence_handle_page_fault().
+	 */
+	WRITE_ONCE(meta->state, next);
+}
+
+/* Write canary byte to @addr. */
+static inline bool set_canary_byte(u8 *addr)
+{
+	*addr = KFENCE_CANARY_PATTERN(addr);
+	return true;
+}
+
+/* Check canary byte at @addr. */
+static inline bool check_canary_byte(u8 *addr)
+{
+	if (*addr == KFENCE_CANARY_PATTERN(addr))
+		return true;
+
+	atomic_long_inc(&counters[KFENCE_COUNTER_BUGS]);
+	kfence_report_error((unsigned long)addr, addr_to_metadata((unsigned long)addr),
+			    KFENCE_ERROR_CORRUPTION);
+	return false;
+}
+
+static inline void for_each_canary(const struct kfence_metadata *meta, bool (*fn)(u8 *))
+{
+	unsigned long addr;
+
+	lockdep_assert_held(&meta->lock);
+
+	for (addr = ALIGN_DOWN(meta->addr, PAGE_SIZE); addr < meta->addr; addr++) {
+		if (!fn((u8 *)addr))
+			break;
+	}
+
+	for (addr = meta->addr + meta->size; addr < PAGE_ALIGN(meta->addr); addr++) {
+		if (!fn((u8 *)addr))
+			break;
+	}
+}
+
+static void *kfence_guarded_alloc(struct kmem_cache *cache, size_t size, gfp_t gfp)
+{
+	struct kfence_metadata *meta = NULL;
+	unsigned long flags;
+	void *addr;
+
+	/* Try to obtain a free object. */
+	raw_spin_lock_irqsave(&kfence_freelist_lock, flags);
+	if (!list_empty(&kfence_freelist)) {
+		meta = list_entry(kfence_freelist.next, struct kfence_metadata, list);
+		list_del_init(&meta->list);
+	}
+	raw_spin_unlock_irqrestore(&kfence_freelist_lock, flags);
+	if (!meta)
+		return NULL;
+
+	if (unlikely(!raw_spin_trylock_irqsave(&meta->lock, flags))) {
+		/*
+		 * This is extremely unlikely -- we are reporting on a
+		 * use-after-free, which locked meta->lock, and the reporting
+		 * code via printk calls kmalloc() which ends up in
+		 * kfence_alloc() and tries to grab the same object that we're
+		 * reporting on. While it has never been observed, lockdep does
+		 * report that there is a possibility of deadlock. Fix it by
+		 * using trylock and bailing out gracefully.
+		 */
+		raw_spin_lock_irqsave(&kfence_freelist_lock, flags);
+		/* Put the object back on the freelist. */
+		list_add_tail(&meta->list, &kfence_freelist);
+		raw_spin_unlock_irqrestore(&kfence_freelist_lock, flags);
+
+		return NULL;
+	}
+
+	meta->addr = metadata_to_pageaddr(meta);
+	/* Unprotect if we're reusing this page. */
+	if (meta->state == KFENCE_OBJECT_FREED)
+		kfence_unprotect(meta->addr);
+
+	/*
+	 * Note: for allocations made before RNG initialization, will always
+	 * return zero. We still benefit from enabling KFENCE as early as
+	 * possible, even when the RNG is not yet available, as this will allow
+	 * KFENCE to detect bugs due to earlier allocations. The only downside
+	 * is that the out-of-bounds accesses detected are deterministic for
+	 * such allocations.
+	 */
+	if (prandom_u32_max(2)) {
+		/* Allocate on the "right" side, re-calculate address. */
+		meta->addr += PAGE_SIZE - size;
+		meta->addr = ALIGN_DOWN(meta->addr, cache->align);
+	}
+
+	/* Update remaining metadata. */
+	metadata_update_state(meta, KFENCE_OBJECT_ALLOCATED);
+	/* Pairs with READ_ONCE() in kfence_shutdown_cache(). */
+	WRITE_ONCE(meta->cache, cache);
+	meta->size = size;
+	for_each_canary(meta, set_canary_byte);
+	virt_to_page(meta->addr)->slab_cache = cache;
+
+	raw_spin_unlock_irqrestore(&meta->lock, flags);
+
+	/* Memory initialization. */
+
+	/*
+	 * We check slab_want_init_on_alloc() ourselves, rather than letting
+	 * SL*B do the initialization, as otherwise we might overwrite KFENCE's
+	 * redzone.
+	 */
+	addr = (void *)meta->addr;
+	if (unlikely(slab_want_init_on_alloc(gfp, cache)))
+		memzero_explicit(addr, size);
+	if (cache->ctor)
+		cache->ctor(addr);
+
+	if (CONFIG_KFENCE_STRESS_TEST_FAULTS && !prandom_u32_max(CONFIG_KFENCE_STRESS_TEST_FAULTS))
+		kfence_protect(meta->addr); /* Random "faults" by protecting the object. */
+
+	atomic_long_inc(&counters[KFENCE_COUNTER_ALLOCATED]);
+	atomic_long_inc(&counters[KFENCE_COUNTER_ALLOCS]);
+
+	return addr;
+}
+
+static void kfence_guarded_free(void *addr, struct kfence_metadata *meta)
+{
+	struct kcsan_scoped_access assert_page_exclusive;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&meta->lock, flags);
+
+	if (meta->state != KFENCE_OBJECT_ALLOCATED || meta->addr != (unsigned long)addr) {
+		/* Invalid or double-free, bail out. */
+		atomic_long_inc(&counters[KFENCE_COUNTER_BUGS]);
+		kfence_report_error((unsigned long)addr, meta, KFENCE_ERROR_INVALID_FREE);
+		raw_spin_unlock_irqrestore(&meta->lock, flags);
+		return;
+	}
+
+	/* Detect racy use-after-free, or incorrect reallocation of this page by KFENCE. */
+	kcsan_begin_scoped_access((void *)ALIGN_DOWN((unsigned long)addr, PAGE_SIZE), PAGE_SIZE,
+				  KCSAN_ACCESS_SCOPED | KCSAN_ACCESS_WRITE | KCSAN_ACCESS_ASSERT,
+				  &assert_page_exclusive);
+
+	if (CONFIG_KFENCE_STRESS_TEST_FAULTS)
+		kfence_unprotect((unsigned long)addr); /* To check canary bytes. */
+
+	/* Restore page protection if there was an OOB access. */
+	if (meta->unprotected_page) {
+		kfence_protect(meta->unprotected_page);
+		meta->unprotected_page = 0;
+	}
+
+	/* Check canary bytes for memory corruption. */
+	for_each_canary(meta, check_canary_byte);
+
+	/*
+	 * Clear memory if init-on-free is set. While we protect the page, the
+	 * data is still there, and after a use-after-free is detected, we
+	 * unprotect the page, so the data is still accessible.
+	 */
+	if (unlikely(slab_want_init_on_free(meta->cache)))
+		memzero_explicit(addr, meta->size);
+
+	/* Mark the object as freed. */
+	metadata_update_state(meta, KFENCE_OBJECT_FREED);
+
+	raw_spin_unlock_irqrestore(&meta->lock, flags);
+
+	/* Protect to detect use-after-frees. */
+	kfence_protect((unsigned long)addr);
+
+	/* Add it to the tail of the freelist for reuse. */
+	raw_spin_lock_irqsave(&kfence_freelist_lock, flags);
+	KFENCE_WARN_ON(!list_empty(&meta->list));
+	list_add_tail(&meta->list, &kfence_freelist);
+	kcsan_end_scoped_access(&assert_page_exclusive);
+	raw_spin_unlock_irqrestore(&kfence_freelist_lock, flags);
+
+	atomic_long_dec(&counters[KFENCE_COUNTER_ALLOCATED]);
+	atomic_long_inc(&counters[KFENCE_COUNTER_FREES]);
+}
+
+static void rcu_guarded_free(struct rcu_head *h)
+{
+	struct kfence_metadata *meta = container_of(h, struct kfence_metadata, rcu_head);
+
+	kfence_guarded_free((void *)meta->addr, meta);
+}
+
+static bool __init kfence_initialize_pool(void)
+{
+	unsigned long addr;
+	struct page *pages;
+	int i;
+
+	if (!arch_kfence_initialize_pool())
+		return false;
+
+	addr = (unsigned long)__kfence_pool;
+	pages = virt_to_page(addr);
+
+	/*
+	 * Set up object pages: they must have PG_slab set, to avoid freeing
+	 * these as real pages.
+	 *
+	 * We also want to avoid inserting kfence_free() in the kfree()
+	 * fast-path in SLUB, and therefore need to ensure kfree() correctly
+	 * enters __slab_free() slow-path.
+	 */
+	for (i = 0; i < KFENCE_POOL_SIZE / PAGE_SIZE; i++) {
+		if (!i || (i % 2))
+			continue;
+
+		__SetPageSlab(&pages[i]);
+	}
+
+	/*
+	 * Protect the first 2 pages. The first page is mostly unnecessary, and
+	 * merely serves as an extended guard page. However, adding one
+	 * additional page in the beginning gives us an even number of pages,
+	 * which simplifies the mapping of address to metadata index.
+	 */
+	for (i = 0; i < 2; i++) {
+		if (unlikely(!kfence_protect(addr)))
+			return false;
+
+		addr += PAGE_SIZE;
+	}
+
+	for (i = 0; i < CONFIG_KFENCE_NUM_OBJECTS; i++) {
+		struct kfence_metadata *meta = &kfence_metadata[i];
+
+		/* Initialize metadata. */
+		INIT_LIST_HEAD(&meta->list);
+		raw_spin_lock_init(&meta->lock);
+		meta->state = KFENCE_OBJECT_UNUSED;
+		meta->addr = addr; /* Initialize for validation in metadata_to_pageaddr(). */
+		list_add_tail(&meta->list, &kfence_freelist);
+
+		/* Protect the right redzone. */
+		if (unlikely(!kfence_protect(addr + PAGE_SIZE)))
+			return false;
+
+		addr += 2 * PAGE_SIZE;
+	}
+
+	return true;
+}
+
+/* === DebugFS Interface ==================================================== */
+
+static int stats_show(struct seq_file *seq, void *v)
+{
+	int i;
+
+	seq_printf(seq, "enabled: %i\n", READ_ONCE(kfence_enabled));
+	for (i = 0; i < KFENCE_COUNTER_COUNT; i++)
+		seq_printf(seq, "%s: %ld\n", counter_names[i], atomic_long_read(&counters[i]));
+
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(stats);
+
+/*
+ * debugfs seq_file operations for /sys/kernel/debug/kfence/objects.
+ * start_object() and next_object() return the object index + 1, because NULL is used
+ * to stop iteration.
+ */
+static void *start_object(struct seq_file *seq, loff_t *pos)
+{
+	if (*pos < CONFIG_KFENCE_NUM_OBJECTS)
+		return (void *)((long)*pos + 1);
+	return NULL;
+}
+
+static void stop_object(struct seq_file *seq, void *v)
+{
+}
+
+static void *next_object(struct seq_file *seq, void *v, loff_t *pos)
+{
+	++*pos;
+	if (*pos < CONFIG_KFENCE_NUM_OBJECTS)
+		return (void *)((long)*pos + 1);
+	return NULL;
+}
+
+static int show_object(struct seq_file *seq, void *v)
+{
+	struct kfence_metadata *meta = &kfence_metadata[(long)v - 1];
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&meta->lock, flags);
+	kfence_print_object(seq, meta);
+	raw_spin_unlock_irqrestore(&meta->lock, flags);
+	seq_puts(seq, "---------------------------------\n");
+
+	return 0;
+}
+
+static const struct seq_operations object_seqops = {
+	.start = start_object,
+	.next = next_object,
+	.stop = stop_object,
+	.show = show_object,
+};
+
+static int open_objects(struct inode *inode, struct file *file)
+{
+	return seq_open(file, &object_seqops);
+}
+
+static const struct file_operations objects_fops = {
+	.open = open_objects,
+	.read = seq_read,
+	.llseek = seq_lseek,
+};
+
+static int __init kfence_debugfs_init(void)
+{
+	struct dentry *kfence_dir = debugfs_create_dir("kfence", NULL);
+
+	debugfs_create_file("stats", 0444, kfence_dir, NULL, &stats_fops);
+	debugfs_create_file("objects", 0400, kfence_dir, NULL, &objects_fops);
+	return 0;
+}
+
+late_initcall(kfence_debugfs_init);
+
+/* === Allocation Gate Timer ================================================ */
+
+/*
+ * Set up delayed work, which will enable and disable the static key. We need to
+ * use a work queue (rather than a simple timer), since enabling and disabling a
+ * static key cannot be done from an interrupt.
+ */
+static struct delayed_work kfence_timer;
+static void toggle_allocation_gate(struct work_struct *work)
+{
+	if (!READ_ONCE(kfence_enabled))
+		return;
+
+	/* Enable static key, and await allocation to happen. */
+	atomic_set(&allocation_gate, 0);
+	static_branch_enable(&kfence_allocation_key);
+	wait_event(allocation_wait, atomic_read(&allocation_gate) != 0);
+
+	/* Disable static key and reset timer. */
+	static_branch_disable(&kfence_allocation_key);
+	schedule_delayed_work(&kfence_timer, msecs_to_jiffies(kfence_sample_interval));
+}
+static DECLARE_DELAYED_WORK(kfence_timer, toggle_allocation_gate);
+
+/* === Public interface ===================================================== */
+
+void __init kfence_init(void)
+{
+	/* Setting kfence_sample_interval to 0 on boot disables KFENCE. */
+	if (!kfence_sample_interval)
+		return;
+
+	if (!kfence_initialize_pool()) {
+		pr_err("%s failed\n", __func__);
+		return;
+	}
+
+	WRITE_ONCE(kfence_enabled, true);
+	schedule_delayed_work(&kfence_timer, 0);
+	pr_info("initialized - using %lu bytes for %d objects", KFENCE_POOL_SIZE,
+		CONFIG_KFENCE_NUM_OBJECTS);
+	if (IS_ENABLED(CONFIG_DEBUG_KERNEL))
+		pr_cont(" at 0x%px-0x%px\n", (void *)__kfence_pool,
+			(void *)(__kfence_pool + KFENCE_POOL_SIZE));
+	else
+		pr_cont("\n");
+}
+
+bool kfence_shutdown_cache(struct kmem_cache *s)
+{
+	unsigned long flags;
+	struct kfence_metadata *meta;
+	int i;
+
+	for (i = 0; i < CONFIG_KFENCE_NUM_OBJECTS; i++) {
+		bool in_use;
+
+		meta = &kfence_metadata[i];
+
+		/*
+		 * If we observe some inconsistent cache and state pair where we
+		 * should have returned false here, cache destruction is racing
+		 * with either kmem_cache_alloc() or kmem_cache_free(). Taking
+		 * the lock will not help, as different critical section
+		 * serialization will have the same outcome.
+		 */
+		if (READ_ONCE(meta->cache) != s ||
+		    READ_ONCE(meta->state) != KFENCE_OBJECT_ALLOCATED)
+			continue;
+
+		raw_spin_lock_irqsave(&meta->lock, flags);
+		in_use = meta->cache == s && meta->state == KFENCE_OBJECT_ALLOCATED;
+		raw_spin_unlock_irqrestore(&meta->lock, flags);
+
+		if (in_use)
+			return false;
+	}
+
+	for (i = 0; i < CONFIG_KFENCE_NUM_OBJECTS; i++) {
+		meta = &kfence_metadata[i];
+
+		/* See above. */
+		if (READ_ONCE(meta->cache) != s || READ_ONCE(meta->state) != KFENCE_OBJECT_FREED)
+			continue;
+
+		raw_spin_lock_irqsave(&meta->lock, flags);
+		if (meta->cache == s && meta->state == KFENCE_OBJECT_FREED)
+			meta->cache = NULL;
+		raw_spin_unlock_irqrestore(&meta->lock, flags);
+	}
+
+	return true;
+}
+
+void *__kfence_alloc(struct kmem_cache *s, size_t size, gfp_t flags)
+{
+	/*
+	 * allocation_gate only needs to become non-zero, so it doesn't make
+	 * sense to continue writing to it and pay the associated contention
+	 * cost, in case we have a large number of concurrent allocations.
+	 */
+	if (atomic_read(&allocation_gate) || atomic_inc_return(&allocation_gate) > 1)
+		return NULL;
+	wake_up(&allocation_wait);
+
+	if (!READ_ONCE(kfence_enabled))
+		return NULL;
+
+	if (size > PAGE_SIZE)
+		return NULL;
+
+	return kfence_guarded_alloc(s, size, flags);
+}
+
+size_t kfence_ksize(const void *addr)
+{
+	const struct kfence_metadata *meta = addr_to_metadata((unsigned long)addr);
+
+	/*
+	 * Read locklessly -- if there is a race with __kfence_alloc(), this is
+	 * either a use-after-free or invalid access.
+	 */
+	return meta ? meta->size : 0;
+}
+
+void *kfence_object_start(const void *addr)
+{
+	const struct kfence_metadata *meta = addr_to_metadata((unsigned long)addr);
+
+	/*
+	 * Read locklessly -- if there is a race with __kfence_alloc(), this is
+	 * either a use-after-free or invalid access.
+	 */
+	return meta ? (void *)meta->addr : NULL;
+}
+
+void __kfence_free(void *addr)
+{
+	struct kfence_metadata *meta = addr_to_metadata((unsigned long)addr);
+
+	/*
+	 * If the objects of the cache are SLAB_TYPESAFE_BY_RCU, defer freeing
+	 * the object, as the object page may be recycled for other-typed
+	 * objects once it has been freed.
+	 */
+	if (unlikely(meta->cache->flags & SLAB_TYPESAFE_BY_RCU))
+		call_rcu(&meta->rcu_head, rcu_guarded_free);
+	else
+		kfence_guarded_free(addr, meta);
+}
+
+bool kfence_handle_page_fault(unsigned long addr)
+{
+	const int page_index = (addr - (unsigned long)__kfence_pool) / PAGE_SIZE;
+	struct kfence_metadata *to_report = NULL;
+	enum kfence_error_type error_type;
+	unsigned long flags;
+
+	if (!is_kfence_address((void *)addr))
+		return false;
+
+	if (!READ_ONCE(kfence_enabled)) /* If disabled at runtime ... */
+		return kfence_unprotect(addr); /* ... unprotect and proceed. */
+
+	atomic_long_inc(&counters[KFENCE_COUNTER_BUGS]);
+
+	if (page_index % 2) {
+		/* This is a redzone, report a buffer overflow. */
+		struct kfence_metadata *meta;
+		int distance = 0;
+
+		meta = addr_to_metadata(addr - PAGE_SIZE);
+		if (meta && READ_ONCE(meta->state) == KFENCE_OBJECT_ALLOCATED) {
+			to_report = meta;
+			/* Data race ok; distance calculation approximate. */
+			distance = addr - data_race(meta->addr + meta->size);
+		}
+
+		meta = addr_to_metadata(addr + PAGE_SIZE);
+		if (meta && READ_ONCE(meta->state) == KFENCE_OBJECT_ALLOCATED) {
+			/* Data race ok; distance calculation approximate. */
+			if (!to_report || distance > data_race(meta->addr) - addr)
+				to_report = meta;
+		}
+
+		if (!to_report)
+			goto out;
+
+		raw_spin_lock_irqsave(&to_report->lock, flags);
+		to_report->unprotected_page = addr;
+		error_type = KFENCE_ERROR_OOB;
+
+		/*
+		 * If the object was freed before we took the look we can still
+		 * report this as an OOB -- the report will simply show the
+		 * stacktrace of the free as well.
+		 */
+	} else {
+		to_report = addr_to_metadata(addr);
+		if (!to_report)
+			goto out;
+
+		raw_spin_lock_irqsave(&to_report->lock, flags);
+		error_type = KFENCE_ERROR_UAF;
+		/*
+		 * We may race with __kfence_alloc(), and it is possible that a
+		 * freed object may be reallocated. We simply report this as a
+		 * use-after-free, with the stack trace showing the place where
+		 * the object was re-allocated.
+		 */
+	}
+
+out:
+	if (to_report) {
+		kfence_report_error(addr, to_report, error_type);
+		raw_spin_unlock_irqrestore(&to_report->lock, flags);
+	} else {
+		/* This may be a UAF or OOB access, but we can't be sure. */
+		kfence_report_error(addr, NULL, KFENCE_ERROR_INVALID);
+	}
+
+	return kfence_unprotect(addr); /* Unprotect and let access proceed. */
+}
diff --git a/mm/kfence/kfence.h b/mm/kfence/kfence.h
new file mode 100644
index 000000000000..2f606a3f58b6
--- /dev/null
+++ b/mm/kfence/kfence.h
@@ -0,0 +1,102 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef MM_KFENCE_KFENCE_H
+#define MM_KFENCE_KFENCE_H
+
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+
+#include "../slab.h" /* for struct kmem_cache */
+
+/* For non-debug builds, avoid leaking kernel pointers into dmesg. */
+#ifdef CONFIG_DEBUG_KERNEL
+#define PTR_FMT "%px"
+#else
+#define PTR_FMT "%p"
+#endif
+
+/*
+ * Get the canary byte pattern for @addr. Use a pattern that varies based on the
+ * lower 3 bits of the address, to detect memory corruptions with higher
+ * probability, where similar constants are used.
+ */
+#define KFENCE_CANARY_PATTERN(addr) ((u8)0xaa ^ (u8)((unsigned long)(addr) & 0x7))
+
+/* Maximum stack depth for reports. */
+#define KFENCE_STACK_DEPTH 64
+
+/* KFENCE object states. */
+enum kfence_object_state {
+	KFENCE_OBJECT_UNUSED,		/* Object is unused. */
+	KFENCE_OBJECT_ALLOCATED,	/* Object is currently allocated. */
+	KFENCE_OBJECT_FREED,		/* Object was allocated, and then freed. */
+};
+
+/* KFENCE metadata per guarded allocation. */
+struct kfence_metadata {
+	struct list_head list;		/* Freelist node; access under kfence_freelist_lock. */
+	struct rcu_head rcu_head;	/* For delayed freeing. */
+
+	/*
+	 * Lock protecting below data; to ensure consistency of the below data,
+	 * since the following may execute concurrently: __kfence_alloc(),
+	 * __kfence_free(), kfence_handle_page_fault(). However, note that we
+	 * cannot grab the same metadata off the freelist twice, and multiple
+	 * __kfence_alloc() cannot run concurrently on the same metadata.
+	 */
+	raw_spinlock_t lock;
+
+	/* The current state of the object; see above. */
+	enum kfence_object_state state;
+
+	/*
+	 * Allocated object address; cannot be calculated from size, because of
+	 * alignment requirements.
+	 *
+	 * Invariant: ALIGN_DOWN(addr, PAGE_SIZE) is constant.
+	 */
+	unsigned long addr;
+
+	/*
+	 * The size of the original allocation.
+	 */
+	size_t size;
+
+	/*
+	 * The kmem_cache cache of the last allocation; NULL if never allocated
+	 * or the cache has already been destroyed.
+	 */
+	struct kmem_cache *cache;
+
+	/*
+	 * In case of an invalid access, the page that was unprotected; we
+	 * optimistically only store address.
+	 */
+	unsigned long unprotected_page;
+
+	/* Allocation and free stack information. */
+	int num_alloc_stack;
+	int num_free_stack;
+	unsigned long alloc_stack[KFENCE_STACK_DEPTH];
+	unsigned long free_stack[KFENCE_STACK_DEPTH];
+};
+
+extern struct kfence_metadata kfence_metadata[CONFIG_KFENCE_NUM_OBJECTS];
+
+/* KFENCE error types for report generation. */
+enum kfence_error_type {
+	KFENCE_ERROR_OOB,		/* Detected a out-of-bounds access. */
+	KFENCE_ERROR_UAF,		/* Detected a use-after-free access. */
+	KFENCE_ERROR_CORRUPTION,	/* Detected a memory corruption on free. */
+	KFENCE_ERROR_INVALID,		/* Invalid access of unknown type. */
+	KFENCE_ERROR_INVALID_FREE,	/* Invalid free. */
+};
+
+void kfence_report_error(unsigned long address, const struct kfence_metadata *meta,
+			 enum kfence_error_type type);
+
+void kfence_print_object(struct seq_file *seq, const struct kfence_metadata *meta);
+
+#endif /* MM_KFENCE_KFENCE_H */
diff --git a/mm/kfence/report.c b/mm/kfence/report.c
new file mode 100644
index 000000000000..e6c6734ae859
--- /dev/null
+++ b/mm/kfence/report.c
@@ -0,0 +1,225 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <stdarg.h>
+
+#include <linux/kernel.h>
+#include <linux/lockdep.h>
+#include <linux/printk.h>
+#include <linux/seq_file.h>
+#include <linux/stacktrace.h>
+#include <linux/string.h>
+
+#include <asm/kfence.h>
+
+#include "kfence.h"
+
+/* Helper function to either print to a seq_file or to console. */
+__printf(2, 3)
+static void seq_con_printf(struct seq_file *seq, const char *fmt, ...)
+{
+	va_list args;
+
+	va_start(args, fmt);
+	if (seq)
+		seq_vprintf(seq, fmt, args);
+	else
+		vprintk(fmt, args);
+	va_end(args);
+}
+
+/*
+ * Get the number of stack entries to skip get out of MM internals. @type is
+ * optional, and if set to NULL, assumes an allocation or free stack.
+ */
+static int get_stack_skipnr(const unsigned long stack_entries[], int num_entries,
+			    const enum kfence_error_type *type)
+{
+	char buf[64];
+	int skipnr, fallback = 0;
+	bool is_access_fault = false;
+
+	if (type) {
+		/* Depending on error type, find different stack entries. */
+		switch (*type) {
+		case KFENCE_ERROR_UAF:
+		case KFENCE_ERROR_OOB:
+		case KFENCE_ERROR_INVALID:
+			is_access_fault = true;
+			break;
+		case KFENCE_ERROR_CORRUPTION:
+		case KFENCE_ERROR_INVALID_FREE:
+			break;
+		}
+	}
+
+	for (skipnr = 0; skipnr < num_entries; skipnr++) {
+		int len = scnprintf(buf, sizeof(buf), "%ps", (void *)stack_entries[skipnr]);
+
+		if (is_access_fault) {
+			if (!strncmp(buf, KFENCE_SKIP_ARCH_FAULT_HANDLER, len))
+				goto found;
+		} else {
+			if (str_has_prefix(buf, "kfence_") || str_has_prefix(buf, "__kfence_") ||
+			    !strncmp(buf, "__slab_free", len)) {
+				/*
+				 * In case of tail calls from any of the below
+				 * to any of the above.
+				 */
+				fallback = skipnr + 1;
+			}
+
+			/* Also the *_bulk() variants by only checking prefixes. */
+			if (str_has_prefix(buf, "kfree") ||
+			    str_has_prefix(buf, "kmem_cache_free") ||
+			    str_has_prefix(buf, "__kmalloc") ||
+			    str_has_prefix(buf, "kmem_cache_alloc"))
+				goto found;
+		}
+	}
+	if (fallback < num_entries)
+		return fallback;
+found:
+	skipnr++;
+	return skipnr < num_entries ? skipnr : 0;
+}
+
+static void kfence_print_stack(struct seq_file *seq, const struct kfence_metadata *meta,
+			       bool show_alloc)
+{
+	const unsigned long *entries = show_alloc ? meta->alloc_stack : meta->free_stack;
+	const int nentries = show_alloc ? meta->num_alloc_stack : meta->num_free_stack;
+
+	if (nentries) {
+		/* Skip allocation/free internals stack. */
+		int i = get_stack_skipnr(entries, nentries, NULL);
+
+		/* stack_trace_seq_print() does not exist; open code our own. */
+		for (; i < nentries; i++)
+			seq_con_printf(seq, " %pS\n", (void *)entries[i]);
+	} else {
+		seq_con_printf(seq, " no %s stack\n", show_alloc ? "allocation" : "deallocation");
+	}
+}
+
+void kfence_print_object(struct seq_file *seq, const struct kfence_metadata *meta)
+{
+	const int size = abs(meta->size);
+	const unsigned long start = meta->addr;
+	const struct kmem_cache *const cache = meta->cache;
+
+	lockdep_assert_held(&meta->lock);
+
+	if (meta->state == KFENCE_OBJECT_UNUSED) {
+		seq_con_printf(seq, "kfence-#%zd unused\n", meta - kfence_metadata);
+		return;
+	}
+
+	seq_con_printf(seq,
+		       "kfence-#%zd [0x" PTR_FMT "-0x" PTR_FMT
+		       ", size=%d, cache=%s] allocated in:\n",
+		       meta - kfence_metadata, (void *)start, (void *)(start + size - 1), size,
+		       (cache && cache->name) ? cache->name : "<destroyed>");
+	kfence_print_stack(seq, meta, true);
+
+	if (meta->state == KFENCE_OBJECT_FREED) {
+		seq_con_printf(seq, "\nfreed in:\n");
+		kfence_print_stack(seq, meta, false);
+	}
+}
+
+/*
+ * Show bytes at @addr that are different from the expected canary values, up to
+ * @max_bytes.
+ */
+static void print_diff_canary(const u8 *addr, size_t max_bytes)
+{
+	const u8 *max_addr = min((const u8 *)PAGE_ALIGN((unsigned long)addr), addr + max_bytes);
+
+	pr_cont("[");
+	for (; addr < max_addr; addr++) {
+		if (*addr == KFENCE_CANARY_PATTERN(addr))
+			pr_cont(" .");
+		else if (IS_ENABLED(CONFIG_DEBUG_KERNEL))
+			pr_cont(" 0x%02x", *addr);
+		else /* Do not leak kernel memory in non-debug builds. */
+			pr_cont(" !");
+	}
+	pr_cont(" ]");
+}
+
+void kfence_report_error(unsigned long address, const struct kfence_metadata *meta,
+			 enum kfence_error_type type)
+{
+	unsigned long stack_entries[KFENCE_STACK_DEPTH] = { 0 };
+	int num_stack_entries = stack_trace_save(stack_entries, KFENCE_STACK_DEPTH, 1);
+	int skipnr = get_stack_skipnr(stack_entries, num_stack_entries, &type);
+	const ptrdiff_t object_index = meta ? meta - kfence_metadata : -1;
+
+	/* Require non-NULL meta, except if KFENCE_ERROR_INVALID. */
+	if (WARN_ON(type != KFENCE_ERROR_INVALID && !meta))
+		return;
+
+	if (meta)
+		lockdep_assert_held(&meta->lock);
+	/*
+	 * Because we may generate reports in printk-unfriendly parts of the
+	 * kernel, such as scheduler code, the use of printk() could deadlock.
+	 * Until such time that all printing code here is safe in all parts of
+	 * the kernel, accept the risk, and just get our message out (given the
+	 * system might already behave unpredictably due to the memory error).
+	 * As such, also disable lockdep to hide warnings, and avoid disabling
+	 * lockdep for the rest of the kernel.
+	 */
+	lockdep_off();
+
+	pr_err("==================================================================\n");
+	/* Print report header. */
+	switch (type) {
+	case KFENCE_ERROR_OOB:
+		pr_err("BUG: KFENCE: out-of-bounds in %pS\n\n", (void *)stack_entries[skipnr]);
+		pr_err("Out-of-bounds access at 0x" PTR_FMT " (%s of kfence-#%zd):\n",
+		       (void *)address, address < meta->addr ? "left" : "right", object_index);
+		break;
+	case KFENCE_ERROR_UAF:
+		pr_err("BUG: KFENCE: use-after-free in %pS\n\n", (void *)stack_entries[skipnr]);
+		pr_err("Use-after-free access at 0x" PTR_FMT " (in kfence-#%zd):\n",
+		       (void *)address, object_index);
+		break;
+	case KFENCE_ERROR_CORRUPTION:
+		pr_err("BUG: KFENCE: memory corruption in %pS\n\n", (void *)stack_entries[skipnr]);
+		pr_err("Corrupted memory at 0x" PTR_FMT " ", (void *)address);
+		print_diff_canary((u8 *)address, 16);
+		pr_cont(" (in kfence-#%zd):\n", object_index);
+		break;
+	case KFENCE_ERROR_INVALID:
+		pr_err("BUG: KFENCE: invalid access in %pS\n\n", (void *)stack_entries[skipnr]);
+		pr_err("Invalid access at 0x" PTR_FMT ":\n", (void *)address);
+		break;
+	case KFENCE_ERROR_INVALID_FREE:
+		pr_err("BUG: KFENCE: invalid free in %pS\n\n", (void *)stack_entries[skipnr]);
+		pr_err("Invalid free of 0x" PTR_FMT " (in kfence-#%zd):\n", (void *)address,
+		       object_index);
+		break;
+	}
+
+	/* Print stack trace and object info. */
+	stack_trace_print(stack_entries + skipnr, num_stack_entries - skipnr, 0);
+
+	if (meta) {
+		pr_err("\n");
+		kfence_print_object(NULL, meta);
+	}
+
+	/* Print report footer. */
+	pr_err("\n");
+	dump_stack_print_info(KERN_DEFAULT);
+	pr_err("==================================================================\n");
+
+	lockdep_on();
+
+	if (panic_on_warn)
+		panic("panic_on_warn set ...\n");
+
+	/* We encountered a memory unsafety error, taint the kernel! */
+	add_taint(TAINT_WARN, LOCKDEP_STILL_OK);
+}
