kasan: HW_TAGS tests support and fixes

index b25167664ead..eedc3e0fe365 100644
@@ -60,7 +60,7 @@ void kasan_disable_current(void)
 
 void __kasan_unpoison_range(const void *address, size_t size)
 {
-	unpoison_range(address, size);
+	kasan_unpoison(address, size);
 }
 
 #if CONFIG_KASAN_STACK

@@ -69,7 +69,7 @@ void kasan_unpoison_task_stack(struct task_struct *task)
 {
 	void *base = task_stack_page(task);
 
-	unpoison_range(base, THREAD_SIZE);
+	kasan_unpoison(base, THREAD_SIZE);
 }
 
 /* Unpoison the stack for the current task beyond a watermark sp value. */

@@ -82,7 +82,7 @@ asmlinkage void kasan_unpoison_task_stack_below(const void *watermark)
 	 */
 	void *base = (void *)((unsigned long)watermark & ~(THREAD_SIZE - 1));
 
-	unpoison_range(base, watermark - base);
+	kasan_unpoison(base, watermark - base);
 }
 #endif /* CONFIG_KASAN_STACK */
 

@@ -105,18 +105,17 @@ void __kasan_alloc_pages(struct page *page, unsigned int order)
 	if (unlikely(PageHighMem(page)))
 		return;
 
-	tag = random_tag();
+	tag = kasan_random_tag();
 	for (i = 0; i < (1 << order); i++)
 		page_kasan_tag_set(page + i, tag);
-	unpoison_range(page_address(page), PAGE_SIZE << order);
+	kasan_unpoison(page_address(page), PAGE_SIZE << order);
 }
 
 void __kasan_free_pages(struct page *page, unsigned int order)
 {
 	if (likely(!PageHighMem(page)))
-		poison_range(page_address(page),
-				PAGE_SIZE << order,
-				KASAN_FREE_PAGE);
+		kasan_poison(page_address(page), PAGE_SIZE << order,
+			     KASAN_FREE_PAGE);
 }
 
 /*

@@ -246,18 +245,18 @@ void __kasan_poison_slab(struct page *page)
 
 	for (i = 0; i < compound_nr(page); i++)
 		page_kasan_tag_reset(page + i);
-	poison_range(page_address(page), page_size(page),
+	kasan_poison(page_address(page), page_size(page),
 		     KASAN_KMALLOC_REDZONE);
 }
 
 void __kasan_unpoison_object_data(struct kmem_cache *cache, void *object)
 {
-	unpoison_range(object, cache->object_size);
+	kasan_unpoison(object, cache->object_size);
 }
 
 void __kasan_poison_object_data(struct kmem_cache *cache, void *object)
 {
-	poison_range(object, cache->object_size, KASAN_KMALLOC_REDZONE);
+	kasan_poison(object, cache->object_size, KASAN_KMALLOC_REDZONE);
 }
 
 /*

@@ -294,7 +293,7 @@ static u8 assign_tag(struct kmem_cache *cache, const void *object,
 	 * set, assign a tag when the object is being allocated (init == false).
 	 */
 	if (!cache->ctor && !(cache->flags & SLAB_TYPESAFE_BY_RCU))
-		return init ? KASAN_TAG_KERNEL : random_tag();
+		return init ? KASAN_TAG_KERNEL : kasan_random_tag();
 
 	/* For caches that either have a constructor or SLAB_TYPESAFE_BY_RCU: */
 #ifdef CONFIG_SLAB

@@ -305,7 +304,7 @@ static u8 assign_tag(struct kmem_cache *cache, const void *object,
 	 * For SLUB assign a random tag during slab creation, otherwise reuse
 	 * the already assigned tag.
 	 */
-	return init ? random_tag() : get_tag(object);
+	return init ? kasan_random_tag() : get_tag(object);
 #endif
 }
 

@@ -346,12 +345,12 @@ static bool ____kasan_slab_free(struct kmem_cache *cache, void *object,
 	if (unlikely(cache->flags & SLAB_TYPESAFE_BY_RCU))
 		return false;
 
-	if (check_invalid_free(tagged_object)) {
+	if (kasan_check_invalid_free(tagged_object)) {
 		kasan_report_invalid_free(tagged_object, ip);
 		return true;
 	}
 
-	poison_range(object, cache->object_size, KASAN_KMALLOC_FREE);
+	kasan_poison(object, cache->object_size, KASAN_KMALLOC_FREE);
 
 	if (!kasan_stack_collection_enabled())
 		return false;

@@ -361,7 +360,7 @@ static bool ____kasan_slab_free(struct kmem_cache *cache, void *object,
 
 	kasan_set_free_info(cache, object, tag);
 
-	return quarantine_put(cache, object);
+	return kasan_quarantine_put(cache, object);
 }
 
 bool __kasan_slab_free(struct kmem_cache *cache, void *object, unsigned long ip)

@@ -386,7 +385,7 @@ void __kasan_slab_free_mempool(void *ptr, unsigned long ip)
 			kasan_report_invalid_free(ptr, ip);
 			return;
 		}
-		poison_range(ptr, page_size(page), KASAN_FREE_PAGE);
+		kasan_poison(ptr, page_size(page), KASAN_FREE_PAGE);
 	} else {
 		____kasan_slab_free(page->slab_cache, ptr, ip, false);
 	}

@@ -409,7 +408,7 @@ static void *____kasan_kmalloc(struct kmem_cache *cache, const void *object,
 	u8 tag;
 
 	if (gfpflags_allow_blocking(flags))
-		quarantine_reduce();
+		kasan_quarantine_reduce();
 
 	if (unlikely(object == NULL))
 		return NULL;

@@ -421,9 +420,9 @@ static void *____kasan_kmalloc(struct kmem_cache *cache, const void *object,
 	tag = assign_tag(cache, object, false, keep_tag);
 
 	/* Tag is ignored in set_tag without CONFIG_KASAN_SW/HW_TAGS */
-	unpoison_range(set_tag(object, tag), size);
-	poison_range((void *)redzone_start, redzone_end - redzone_start,
-		     KASAN_KMALLOC_REDZONE);
+	kasan_unpoison(set_tag(object, tag), size);
+	kasan_poison((void *)redzone_start, redzone_end - redzone_start,
+			   KASAN_KMALLOC_REDZONE);
 
 	if (kasan_stack_collection_enabled())
 		set_alloc_info(cache, (void *)object, flags);

@@ -452,7 +451,7 @@ void * __must_check __kasan_kmalloc_large(const void *ptr, size_t size,
 	unsigned long redzone_end;
 
 	if (gfpflags_allow_blocking(flags))
-		quarantine_reduce();
+		kasan_quarantine_reduce();
 
 	if (unlikely(ptr == NULL))
 		return NULL;

@@ -462,8 +461,8 @@ void * __must_check __kasan_kmalloc_large(const void *ptr, size_t size,
 				KASAN_GRANULE_SIZE);
 	redzone_end = (unsigned long)ptr + page_size(page);
 
-	unpoison_range(ptr, size);
-	poison_range((void *)redzone_start, redzone_end - redzone_start,
+	kasan_unpoison(ptr, size);
+	kasan_poison((void *)redzone_start, redzone_end - redzone_start,
 		     KASAN_PAGE_REDZONE);
 
 	return (void *)ptr;

index 5106b84b07d4..acab8862dc67 100644
@@ -158,7 +158,7 @@ static __always_inline bool memory_is_poisoned(unsigned long addr, size_t size)
 	return memory_is_poisoned_n(addr, size);
 }
 
-static __always_inline bool check_memory_region_inline(unsigned long addr,
+static __always_inline bool check_region_inline(unsigned long addr,
 						size_t size, bool write,
 						unsigned long ret_ip)
 {

@@ -179,13 +179,13 @@ static __always_inline bool check_memory_region_inline(unsigned long addr,
 	return !kasan_report(addr, size, write, ret_ip);
 }
 
-bool check_memory_region(unsigned long addr, size_t size, bool write,
-				unsigned long ret_ip)
+bool kasan_check_range(unsigned long addr, size_t size, bool write,
+					unsigned long ret_ip)
 {
-	return check_memory_region_inline(addr, size, write, ret_ip);
+	return check_region_inline(addr, size, write, ret_ip);
 }
 
-bool check_invalid_free(void *addr)
+bool kasan_check_invalid_free(void *addr)
 {
 	s8 shadow_byte = READ_ONCE(*(s8 *)kasan_mem_to_shadow(addr));
 

@@ -194,22 +194,22 @@ bool check_invalid_free(void *addr)
 
 void kasan_cache_shrink(struct kmem_cache *cache)
 {
-	quarantine_remove_cache(cache);
+	kasan_quarantine_remove_cache(cache);
 }
 
 void kasan_cache_shutdown(struct kmem_cache *cache)
 {
 	if (!__kmem_cache_empty(cache))
-		quarantine_remove_cache(cache);
+		kasan_quarantine_remove_cache(cache);
 }
 
 static void register_global(struct kasan_global *global)
 {
 	size_t aligned_size = round_up(global->size, KASAN_GRANULE_SIZE);
 
-	unpoison_range(global->beg, global->size);
+	kasan_unpoison(global->beg, global->size);
 
-	poison_range(global->beg + aligned_size,
+	kasan_poison(global->beg + aligned_size,
 		     global->size_with_redzone - aligned_size,
 		     KASAN_GLOBAL_REDZONE);
 }

@@ -231,7 +231,7 @@ EXPORT_SYMBOL(__asan_unregister_globals);
 #define DEFINE_ASAN_LOAD_STORE(size)					\
 	void __asan_load##size(unsigned long addr)			\
 	{								\
-		check_memory_region_inline(addr, size, false, _RET_IP_);\
+		check_region_inline(addr, size, false, _RET_IP_);	\
 	}								\
 	EXPORT_SYMBOL(__asan_load##size);				\
 	__alias(__asan_load##size)					\

@@ -239,7 +239,7 @@ EXPORT_SYMBOL(__asan_unregister_globals);
 	EXPORT_SYMBOL(__asan_load##size##_noabort);			\
 	void __asan_store##size(unsigned long addr)			\
 	{								\
-		check_memory_region_inline(addr, size, true, _RET_IP_);	\
+		check_region_inline(addr, size, true, _RET_IP_);	\
 	}								\
 	EXPORT_SYMBOL(__asan_store##size);				\
 	__alias(__asan_store##size)					\

@@ -254,7 +254,7 @@ DEFINE_ASAN_LOAD_STORE(16);
 
 void __asan_loadN(unsigned long addr, size_t size)
 {
-	check_memory_region(addr, size, false, _RET_IP_);
+	kasan_check_range(addr, size, false, _RET_IP_);
 }
 EXPORT_SYMBOL(__asan_loadN);
 

@@ -264,7 +264,7 @@ EXPORT_SYMBOL(__asan_loadN_noabort);
 
 void __asan_storeN(unsigned long addr, size_t size)
 {
-	check_memory_region(addr, size, true, _RET_IP_);
+	kasan_check_range(addr, size, true, _RET_IP_);
 }
 EXPORT_SYMBOL(__asan_storeN);
 

@@ -290,11 +290,11 @@ void __asan_alloca_poison(unsigned long addr, size_t size)
 
 	WARN_ON(!IS_ALIGNED(addr, KASAN_ALLOCA_REDZONE_SIZE));
 
-	unpoison_range((const void *)(addr + rounded_down_size),
-		       size - rounded_down_size);
-	poison_range(left_redzone, KASAN_ALLOCA_REDZONE_SIZE,
+	kasan_unpoison((const void *)(addr + rounded_down_size),
+			size - rounded_down_size);
+	kasan_poison(left_redzone, KASAN_ALLOCA_REDZONE_SIZE,
 		     KASAN_ALLOCA_LEFT);
-	poison_range(right_redzone, padding_size + KASAN_ALLOCA_REDZONE_SIZE,
+	kasan_poison(right_redzone, padding_size + KASAN_ALLOCA_REDZONE_SIZE,
 		     KASAN_ALLOCA_RIGHT);
 }
 EXPORT_SYMBOL(__asan_alloca_poison);

@@ -305,7 +305,7 @@ void __asan_allocas_unpoison(const void *stack_top, const void *stack_bottom)
 	if (unlikely(!stack_top || stack_top > stack_bottom))
 		return;
 
-	unpoison_range(stack_top, stack_bottom - stack_top);
+	kasan_unpoison(stack_top, stack_bottom - stack_top);
 }
 EXPORT_SYMBOL(__asan_allocas_unpoison);
 

107 lines not on this page · raw message

index 55783125a767..728fb24c5683 100644
@@ -168,7 +168,7 @@ static void qlist_free_all(struct qlist_head *q, struct kmem_cache *cache)
 	qlist_init(q);
 }
 
-bool quarantine_put(struct kmem_cache *cache, void *object)
+bool kasan_quarantine_put(struct kmem_cache *cache, void *object)
 {
 	unsigned long flags;
 	struct qlist_head *q;

@@ -184,11 +184,11 @@ bool quarantine_put(struct kmem_cache *cache, void *object)
 
 	/*
 	 * Note: irq must be disabled until after we move the batch to the
-	 * global quarantine. Otherwise quarantine_remove_cache() can miss
-	 * some objects belonging to the cache if they are in our local temp
-	 * list. quarantine_remove_cache() executes on_each_cpu() at the
-	 * beginning which ensures that it either sees the objects in per-cpu
-	 * lists or in the global quarantine.
+	 * global quarantine. Otherwise kasan_quarantine_remove_cache() can
+	 * miss some objects belonging to the cache if they are in our local
+	 * temp list. kasan_quarantine_remove_cache() executes on_each_cpu()
+	 * at the beginning which ensures that it either sees the objects in
+	 * per-cpu lists or in the global quarantine.
 	 */
 	local_irq_save(flags);
 

@@ -222,7 +222,7 @@ bool quarantine_put(struct kmem_cache *cache, void *object)
 	return true;
 }
 
-void quarantine_reduce(void)
+void kasan_quarantine_reduce(void)
 {
 	size_t total_size, new_quarantine_size, percpu_quarantines;
 	unsigned long flags;

@@ -234,7 +234,7 @@ void quarantine_reduce(void)
 		return;
 
 	/*
-	 * srcu critical section ensures that quarantine_remove_cache()
+	 * srcu critical section ensures that kasan_quarantine_remove_cache()
 	 * will not miss objects belonging to the cache while they are in our
 	 * local to_free list. srcu is chosen because (1) it gives us private
 	 * grace period domain that does not interfere with anything else,

@@ -309,15 +309,15 @@ static void per_cpu_remove_cache(void *arg)
 }
 
 /* Free all quarantined objects belonging to cache. */
-void quarantine_remove_cache(struct kmem_cache *cache)
+void kasan_quarantine_remove_cache(struct kmem_cache *cache)
 {
 	unsigned long flags, i;
 	struct qlist_head to_free = QLIST_INIT;
 
 	/*
 	 * Must be careful to not miss any objects that are being moved from
-	 * per-cpu list to the global quarantine in quarantine_put(),
-	 * nor objects being freed in quarantine_reduce(). on_each_cpu()
+	 * per-cpu list to the global quarantine in kasan_quarantine_put(),
+	 * nor objects being freed in kasan_quarantine_reduce(). on_each_cpu()
 	 * achieves the first goal, while synchronize_srcu() achieves the
 	 * second.
 	 */

index c0fb21797550..e93d7973792e 100644
@@ -61,7 +61,7 @@ __setup("kasan_multi_shot", kasan_set_multi_shot);
 static void print_error_description(struct kasan_access_info *info)
 {
 	pr_err("BUG: KASAN: %s in %pS\n",
-		get_bug_type(info), (void *)info->ip);
+		kasan_get_bug_type(info), (void *)info->ip);
 	if (info->access_size)
 		pr_err("%s of size %zu at addr %px by task %s/%d\n",
 			info->is_write ? "Write" : "Read", info->access_size,

@@ -247,7 +247,7 @@ static void print_address_description(void *addr, u8 tag)
 		dump_page(page, "kasan: bad access detected");
 	}
 
-	print_address_stack_frame(addr);
+	kasan_print_address_stack_frame(addr);
 }
 
 static bool meta_row_is_guilty(const void *row, const void *addr)

@@ -293,7 +293,7 @@ static void print_memory_metadata(const void *addr)
 		 * function, because generic functions may try to
 		 * access kasan mapping for the passed address.
 		 */
-		metadata_fetch_row(&metadata[0], row);
+		kasan_metadata_fetch_row(&metadata[0], row);
 
 		print_hex_dump(KERN_ERR, buffer,
 			DUMP_PREFIX_NONE, META_BYTES_PER_ROW, 1,

@@ -350,7 +350,7 @@ void kasan_report_invalid_free(void *object, unsigned long ip)
 
 	start_report(&flags);
 	pr_err("BUG: KASAN: double-free or invalid-free in %pS\n", (void *)ip);
-	print_tags(tag, object);
+	kasan_print_tags(tag, object);
 	pr_err("\n");
 	print_address_description(object, tag);
 	pr_err("\n");

@@ -378,7 +378,8 @@ static void __kasan_report(unsigned long addr, size_t size, bool is_write,
 
 	info.access_addr = tagged_addr;
 	if (addr_has_metadata(untagged_addr))
-		info.first_bad_addr = find_first_bad_addr(tagged_addr, size);
+		info.first_bad_addr =
+			kasan_find_first_bad_addr(tagged_addr, size);
 	else
 		info.first_bad_addr = untagged_addr;
 	info.access_size = size;

@@ -389,7 +390,7 @@ static void __kasan_report(unsigned long addr, size_t size, bool is_write,
 
 	print_error_description(&info);
 	if (addr_has_metadata(untagged_addr))
-		print_tags(get_tag(tagged_addr), info.first_bad_addr);
+		kasan_print_tags(get_tag(tagged_addr), info.first_bad_addr);
 	pr_err("\n");
 
 	if (addr_has_metadata(untagged_addr)) {

index 8a9c889872da..41f374585144 100644
@@ -30,7 +30,7 @@
 #include "kasan.h"
 #include "../slab.h"
 
-void *find_first_bad_addr(void *addr, size_t size)
+void *kasan_find_first_bad_addr(void *addr, size_t size)
 {
 	void *p = addr;
 

@@ -105,7 +105,7 @@ static const char *get_wild_bug_type(struct kasan_access_info *info)
 	return bug_type;
 }
 
-const char *get_bug_type(struct kasan_access_info *info)
+const char *kasan_get_bug_type(struct kasan_access_info *info)
 {
 	/*
 	 * If access_size is a negative number, then it has reason to be

@@ -123,7 +123,7 @@ const char *get_bug_type(struct kasan_access_info *info)
 	return get_wild_bug_type(info);
 }
 
-void metadata_fetch_row(char *buffer, void *row)
+void kasan_metadata_fetch_row(char *buffer, void *row)
 {
 	memcpy(buffer, kasan_mem_to_shadow(row), META_BYTES_PER_ROW);
 }

@@ -263,7 +263,7 @@ static bool __must_check get_address_stack_frame_info(const void *addr,
 	return true;
 }
 
-void print_address_stack_frame(const void *addr)
+void kasan_print_address_stack_frame(const void *addr)
 {
 	unsigned long offset;
 	const char *frame_descr;

index 57114f0e14d1..42b2168755d6 100644
@@ -15,17 +15,17 @@
 
 #include "kasan.h"
 
-const char *get_bug_type(struct kasan_access_info *info)
+const char *kasan_get_bug_type(struct kasan_access_info *info)
 {
 	return "invalid-access";
 }
 
-void *find_first_bad_addr(void *addr, size_t size)
+void *kasan_find_first_bad_addr(void *addr, size_t size)
 {
 	return kasan_reset_tag(addr);
 }
 
-void metadata_fetch_row(char *buffer, void *row)
+void kasan_metadata_fetch_row(char *buffer, void *row)
 {
 	int i;
 

@@ -33,7 +33,7 @@ void metadata_fetch_row(char *buffer, void *row)
 		buffer[i] = hw_get_mem_tag(row + i * KASAN_GRANULE_SIZE);
 }
 
-void print_tags(u8 addr_tag, const void *addr)
+void kasan_print_tags(u8 addr_tag, const void *addr)
 {
 	u8 memory_tag = hw_get_mem_tag((void *)addr);
 

index 1b026793ad57..3d20d3451d9e 100644
@@ -29,7 +29,7 @@
 #include "kasan.h"
 #include "../slab.h"
 
-const char *get_bug_type(struct kasan_access_info *info)
+const char *kasan_get_bug_type(struct kasan_access_info *info)
 {
 #ifdef CONFIG_KASAN_SW_TAGS_IDENTIFY
 	struct kasan_alloc_meta *alloc_meta;

@@ -72,7 +72,7 @@ const char *get_bug_type(struct kasan_access_info *info)
 	return "invalid-access";
 }
 
-void *find_first_bad_addr(void *addr, size_t size)
+void *kasan_find_first_bad_addr(void *addr, size_t size)
 {
 	u8 tag = get_tag(addr);
 	void *p = kasan_reset_tag(addr);

@@ -83,12 +83,12 @@ void *find_first_bad_addr(void *addr, size_t size)
 	return p;
 }
 
-void metadata_fetch_row(char *buffer, void *row)
+void kasan_metadata_fetch_row(char *buffer, void *row)
 {
 	memcpy(buffer, kasan_mem_to_shadow(row), META_BYTES_PER_ROW);
 }
 
-void print_tags(u8 addr_tag, const void *addr)
+void kasan_print_tags(u8 addr_tag, const void *addr)
 {
 	u8 *shadow = (u8 *)kasan_mem_to_shadow(addr);
 

index 7c2c08c55f32..38958eb0d653 100644
@@ -27,20 +27,20 @@
 
 bool __kasan_check_read(const volatile void *p, unsigned int size)
 {
-	return check_memory_region((unsigned long)p, size, false, _RET_IP_);
+	return kasan_check_range((unsigned long)p, size, false, _RET_IP_);
 }
 EXPORT_SYMBOL(__kasan_check_read);
 
 bool __kasan_check_write(const volatile void *p, unsigned int size)
 {
-	return check_memory_region((unsigned long)p, size, true, _RET_IP_);
+	return kasan_check_range((unsigned long)p, size, true, _RET_IP_);
 }
 EXPORT_SYMBOL(__kasan_check_write);
 
 #undef memset
 void *memset(void *addr, int c, size_t len)
 {
-	if (!check_memory_region((unsigned long)addr, len, true, _RET_IP_))
+	if (!kasan_check_range((unsigned long)addr, len, true, _RET_IP_))
 		return NULL;
 
 	return __memset(addr, c, len);

@@ -50,8 +50,8 @@ void *memset(void *addr, int c, size_t len)
 #undef memmove
 void *memmove(void *dest, const void *src, size_t len)
 {
-	if (!check_memory_region((unsigned long)src, len, false, _RET_IP_) ||
-	    !check_memory_region((unsigned long)dest, len, true, _RET_IP_))
+	if (!kasan_check_range((unsigned long)src, len, false, _RET_IP_) ||
+	    !kasan_check_range((unsigned long)dest, len, true, _RET_IP_))
 		return NULL;
 
 	return __memmove(dest, src, len);

@@ -61,8 +61,8 @@ void *memmove(void *dest, const void *src, size_t len)
 #undef memcpy
 void *memcpy(void *dest, const void *src, size_t len)
 {
-	if (!check_memory_region((unsigned long)src, len, false, _RET_IP_) ||
-	    !check_memory_region((unsigned long)dest, len, true, _RET_IP_))
+	if (!kasan_check_range((unsigned long)src, len, false, _RET_IP_) ||
+	    !kasan_check_range((unsigned long)dest, len, true, _RET_IP_))
 		return NULL;
 
 	return __memcpy(dest, src, len);

@@ -72,7 +72,7 @@ void *memcpy(void *dest, const void *src, size_t len)
  * Poisons the shadow memory for 'size' bytes starting from 'addr'.
  * Memory addresses should be aligned to KASAN_GRANULE_SIZE.
  */
-void poison_range(const void *address, size_t size, u8 value)
+void kasan_poison(const void *address, size_t size, u8 value)
 {
 	void *shadow_start, *shadow_end;
 

@@ -90,7 +90,7 @@ void poison_range(const void *address, size_t size, u8 value)
 	__memset(shadow_start, value, shadow_end - shadow_start);
 }
 
-void unpoison_range(const void *address, size_t size)
+void kasan_unpoison(const void *address, size_t size)
 {
 	u8 tag = get_tag(address);
 

@@ -101,7 +101,7 @@ void unpoison_range(const void *address, size_t size)
 	 */
 	address = kasan_reset_tag(address);
 
-	poison_range(address, size, tag);
+	kasan_poison(address, size, tag);
 
 	if (size & KASAN_GRANULE_MASK) {
 		u8 *shadow = (u8 *)kasan_mem_to_shadow(address + size);

@@ -286,7 +286,7 @@ int kasan_populate_vmalloc(unsigned long addr, unsigned long size)
 	 * // vmalloc() allocates memory
 	 * // let a = area->addr
 	 * // we reach kasan_populate_vmalloc
-	 * // and call unpoison_range:
+	 * // and call kasan_unpoison:
 	 * STORE shadow(a), unpoison_val
 	 * ...
 	 * STORE shadow(a+99), unpoison_val	x = LOAD p

@@ -321,7 +321,7 @@ void kasan_poison_vmalloc(const void *start, unsigned long size)
 		return;
 
 	size = round_up(size, KASAN_GRANULE_SIZE);
-	poison_range(start, size, KASAN_VMALLOC_INVALID);
+	kasan_poison(start, size, KASAN_VMALLOC_INVALID);
 }
 
 void kasan_unpoison_vmalloc(const void *start, unsigned long size)

@@ -329,7 +329,7 @@ void kasan_unpoison_vmalloc(const void *start, unsigned long size)
 	if (!is_vmalloc_or_module_addr(start))
 		return;
 
-	unpoison_range(start, size);
+	kasan_unpoison(start, size);
 }
 
 static int kasan_depopulate_vmalloc_pte(pte_t *ptep, unsigned long addr,

index 5dcd830805b2..cc271fceb5d5 100644
@@ -57,7 +57,7 @@ void __init kasan_init_sw_tags(void)
  * sequence has in fact positive effect, since interrupts that randomly skew
  * PRNG at unpredictable points do only good.
  */
-u8 random_tag(void)
+u8 kasan_random_tag(void)
 {
 	u32 state = this_cpu_read(prng_state);
 

@@ -67,7 +67,7 @@ u8 random_tag(void)
 	return (u8)(state % (KASAN_TAG_MAX + 1));
 }
 
-bool check_memory_region(unsigned long addr, size_t size, bool write,
+bool kasan_check_range(unsigned long addr, size_t size, bool write,
 				unsigned long ret_ip)
 {
 	u8 tag;

@@ -118,7 +118,7 @@ bool check_memory_region(unsigned long addr, size_t size, bool write,
 	return true;
 }
 
-bool check_invalid_free(void *addr)
+bool kasan_check_invalid_free(void *addr)
 {
 	u8 tag = get_tag(addr);
 	u8 shadow_byte = READ_ONCE(*(u8 *)kasan_mem_to_shadow(kasan_reset_tag(addr)));

@@ -130,12 +130,12 @@ bool check_invalid_free(void *addr)
 #define DEFINE_HWASAN_LOAD_STORE(size)					\
 	void __hwasan_load##size##_noabort(unsigned long addr)		\
 	{								\
-		check_memory_region(addr, size, false, _RET_IP_);	\
+		kasan_check_range(addr, size, false, _RET_IP_);	\
 	}								\
 	EXPORT_SYMBOL(__hwasan_load##size##_noabort);			\
 	void __hwasan_store##size##_noabort(unsigned long addr)		\
 	{								\
-		check_memory_region(addr, size, true, _RET_IP_);	\
+		kasan_check_range(addr, size, true, _RET_IP_);		\
 	}								\
 	EXPORT_SYMBOL(__hwasan_store##size##_noabort)
 

@@ -147,19 +147,19 @@ DEFINE_HWASAN_LOAD_STORE(16);
 
 void __hwasan_loadN_noabort(unsigned long addr, unsigned long size)
 {
-	check_memory_region(addr, size, false, _RET_IP_);
+	kasan_check_range(addr, size, false, _RET_IP_);
 }
 EXPORT_SYMBOL(__hwasan_loadN_noabort);
 
 void __hwasan_storeN_noabort(unsigned long addr, unsigned long size)
 {
-	check_memory_region(addr, size, true, _RET_IP_);
+	kasan_check_range(addr, size, true, _RET_IP_);
 }
 EXPORT_SYMBOL(__hwasan_storeN_noabort);
 
 void __hwasan_tag_memory(unsigned long addr, u8 tag, unsigned long size)
 {
-	poison_range((void *)addr, size, tag);
+	kasan_poison((void *)addr, size, tag);
 }
 EXPORT_SYMBOL(__hwasan_tag_memory);
 

index 5f8d3eed78a1..5b2a22591ea7 100644
@@ -576,7 +576,7 @@ static void add_ignores(struct objtool_file *file)
 static const char *uaccess_safe_builtin[] = {
 	/* KASAN */
 	"kasan_report",
-	"check_memory_region",
+	"kasan_check_range",
 	/* KASAN out-of-line */
 	"__asan_loadN_noabort",
 	"__asan_load1_noabort",

index 2947274cc2d3..6f46e27c2af7 100644
@@ -28,10 +28,9 @@
 #define OOB_TAG_OFF (IS_ENABLED(CONFIG_KASAN_GENERIC) ? 0 : KASAN_GRANULE_SIZE)
 
 /*
- * We assign some test results to these globals to make sure the tests
- * are not eliminated as dead code.
+ * Some tests use these global variables to store return values from function
+ * calls that could otherwise be eliminated by the compiler as dead code.
  */
-
 void *kasan_ptr_result;
 int kasan_int_result;
 

@@ -39,14 +38,13 @@ static struct kunit_resource resource;
 static struct kunit_kasan_expectation fail_data;
 static bool multishot;
 
+/*
+ * Temporarily enable multi-shot mode. Otherwise, KASAN would only report the
+ * first detected bug and panic the kernel if panic_on_warn is enabled.
+ */
 static int kasan_test_init(struct kunit *test)
 {
-	/*
-	 * Temporarily enable multi-shot mode and set panic_on_warn=0.
-	 * Otherwise, we'd only get a report for the first case.
-	 */
 	multishot = kasan_save_enable_multi_shot();
-
 	return 0;
 }
 

@@ -56,12 +54,12 @@ static void kasan_test_exit(struct kunit *test)
 }
 
 /**
- * KUNIT_EXPECT_KASAN_FAIL() - Causes a test failure when the expression does
- * not cause a KASAN error. This uses a KUnit resource named "kasan_data." Do
- * Do not use this name for a KUnit resource outside here.
- *
+ * KUNIT_EXPECT_KASAN_FAIL() - check that the executed expression produces a
+ * KASAN report; causes a test failure otherwise. This relies on a KUnit
+ * resource named "kasan_data". Do not use this name for KUnit resources
+ * outside of KASAN tests.
  */
-#define KUNIT_EXPECT_KASAN_FAIL(test, condition) do { \
+#define KUNIT_EXPECT_KASAN_FAIL(test, expression) do { \
 	fail_data.report_expected = true; \
 	fail_data.report_found = false; \
 	kunit_add_named_resource(test, \

@@ -69,7 +67,7 @@ static void kasan_test_exit(struct kunit *test)
 				NULL, \
 				&resource, \
 				"kasan_data", &fail_data); \
-	condition; \
+	expression; \
 	KUNIT_EXPECT_EQ(test, \
 			fail_data.report_expected, \
 			fail_data.report_found); \

@@ -121,7 +119,8 @@ static void kmalloc_pagealloc_oob_right(struct kunit *test)
 		return;
 	}
 
-	/* Allocate a chunk that does not fit into a SLUB cache to trigger
+	/*
+	 * Allocate a chunk that does not fit into a SLUB cache to trigger
 	 * the page allocator fallback.
 	 */
 	ptr = kmalloc(size, GFP_KERNEL);

@@ -168,7 +167,9 @@ static void kmalloc_large_oob_right(struct kunit *test)
 {
 	char *ptr;
 	size_t size = KMALLOC_MAX_CACHE_SIZE - 256;
-	/* Allocate a chunk that is large enough, but still fits into a slab
+
+	/*
+	 * Allocate a chunk that is large enough, but still fits into a slab
 	 * and does not trigger the page allocator fallback in SLUB.
 	 */
 	ptr = kmalloc(size, GFP_KERNEL);

@@ -469,10 +470,13 @@ static void ksize_unpoisons_memory(struct kunit *test)
 	ptr = kmalloc(size, GFP_KERNEL);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
 	real_size = ksize(ptr);
-	/* This access doesn't trigger an error. */
+
+	/* This access shouldn't trigger a KASAN report. */
 	ptr[size] = 'x';
-	/* This one does. */
+
+	/* This one must. */
 	KUNIT_EXPECT_KASAN_FAIL(test, ptr[real_size] = 'y');
+
 	kfree(ptr);
 }
 

@@ -568,7 +572,7 @@ static void kmem_cache_invalid_free(struct kunit *test)
 		return;
 	}
 
-	/* Trigger invalid free, the object doesn't get freed */
+	/* Trigger invalid free, the object doesn't get freed. */
 	KUNIT_EXPECT_KASAN_FAIL(test, kmem_cache_free(cache, p + 1));
 
 	/*

@@ -585,7 +589,10 @@ static void kasan_memchr(struct kunit *test)
 	char *ptr;
 	size_t size = 24;
 
-	/* See https://bugzilla.kernel.org/show_bug.cgi?id=206337 */
+	/*
+	 * str* functions are not instrumented with CONFIG_AMD_MEM_ENCRYPT.
+	 * See https://bugzilla.kernel.org/show_bug.cgi?id=206337 for details.
+	 */
 	if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT)) {
 		kunit_info(test,
 			"str* functions are not instrumented with CONFIG_AMD_MEM_ENCRYPT");

@@ -610,7 +617,10 @@ static void kasan_memcmp(struct kunit *test)
 	size_t size = 24;
 	int arr[9];
 
-	/* See https://bugzilla.kernel.org/show_bug.cgi?id=206337 */
+	/*
+	 * str* functions are not instrumented with CONFIG_AMD_MEM_ENCRYPT.
+	 * See https://bugzilla.kernel.org/show_bug.cgi?id=206337 for details.
+	 */
 	if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT)) {
 		kunit_info(test,
 			"str* functions are not instrumented with CONFIG_AMD_MEM_ENCRYPT");

@@ -634,7 +644,10 @@ static void kasan_strings(struct kunit *test)
 	char *ptr;
 	size_t size = 24;
 
-	/* See https://bugzilla.kernel.org/show_bug.cgi?id=206337 */
+	/*
+	 * str* functions are not instrumented with CONFIG_AMD_MEM_ENCRYPT.
+	 * See https://bugzilla.kernel.org/show_bug.cgi?id=206337 for details.
+	 */
 	if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT)) {
 		kunit_info(test,
 			"str* functions are not instrumented with CONFIG_AMD_MEM_ENCRYPT");

@@ -706,7 +719,7 @@ static void kasan_bitops_generic(struct kunit *test)
 	}
 
 	/*
-	 * Allocate 1 more byte, which causes kzalloc to round up to 16-bytes;
+	 * Allocate 1 more byte, which causes kzalloc to round up to 16 bytes;
 	 * this way we do not actually corrupt other memory.
 	 */
 	bits = kzalloc(sizeof(*bits) + 1, GFP_KERNEL);

index 3b4cc77992d2..eee017ff8980 100644
@@ -123,8 +123,9 @@ static noinline void __init kasan_workqueue_uaf(void)
 static int __init test_kasan_module_init(void)
 {
 	/*
-	 * Temporarily enable multi-shot mode. Otherwise, we'd only get a
-	 * report for the first case.
+	 * Temporarily enable multi-shot mode. Otherwise, KASAN would only
+	 * report the first detected bug and panic the kernel if panic_on_warn
+	 * is enabled.
 	 */
 	bool multishot = kasan_save_enable_multi_shot();
 

index 6f46e27c2af7..714ea27fcc3e 100644
@@ -73,6 +73,20 @@ static void kasan_test_exit(struct kunit *test)
 			fail_data.report_found); \
 } while (0)
 
+#define KASAN_TEST_NEEDS_CONFIG_ON(test, config) do {			\
+	if (!IS_ENABLED(config)) {					\
+		kunit_info((test), "skipping, " #config " required");	\
+		return;							\
+	}								\
+} while (0)
+
+#define KASAN_TEST_NEEDS_CONFIG_OFF(test, config) do {			\
+	if (IS_ENABLED(config)) {					\
+		kunit_info((test), "skipping, " #config " enabled");	\
+		return;							\
+	}								\
+} while (0)
+
 static void kmalloc_oob_right(struct kunit *test)
 {
 	char *ptr;

@@ -114,10 +128,7 @@ static void kmalloc_pagealloc_oob_right(struct kunit *test)
 	char *ptr;
 	size_t size = KMALLOC_MAX_CACHE_SIZE + 10;
 
-	if (!IS_ENABLED(CONFIG_SLUB)) {
-		kunit_info(test, "CONFIG_SLUB is not enabled.");
-		return;
-	}
+	KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_SLUB);
 
 	/*
 	 * Allocate a chunk that does not fit into a SLUB cache to trigger

@@ -135,10 +146,7 @@ static void kmalloc_pagealloc_uaf(struct kunit *test)
 	char *ptr;
 	size_t size = KMALLOC_MAX_CACHE_SIZE + 10;
 
-	if (!IS_ENABLED(CONFIG_SLUB)) {
-		kunit_info(test, "CONFIG_SLUB is not enabled.");
-		return;
-	}
+	KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_SLUB);
 
 	ptr = kmalloc(size, GFP_KERNEL);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);

@@ -152,10 +160,7 @@ static void kmalloc_pagealloc_invalid_free(struct kunit *test)
 	char *ptr;
 	size_t size = KMALLOC_MAX_CACHE_SIZE + 10;
 
-	if (!IS_ENABLED(CONFIG_SLUB)) {
-		kunit_info(test, "CONFIG_SLUB is not enabled.");
-		return;
-	}
+	KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_SLUB);
 
 	ptr = kmalloc(size, GFP_KERNEL);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);

@@ -218,10 +223,7 @@ static void kmalloc_oob_16(struct kunit *test)
 	} *ptr1, *ptr2;
 
 	/* This test is specifically crafted for the generic mode. */
-	if (!IS_ENABLED(CONFIG_KASAN_GENERIC)) {
-		kunit_info(test, "CONFIG_KASAN_GENERIC required\n");
-		return;
-	}
+	KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_GENERIC);
 
 	ptr1 = kmalloc(sizeof(*ptr1) - 3, GFP_KERNEL);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1);

@@ -454,10 +456,7 @@ static void kasan_global_oob(struct kunit *test)
 	char *p = &global_array[ARRAY_SIZE(global_array) + i];
 
 	/* Only generic mode instruments globals. */
-	if (!IS_ENABLED(CONFIG_KASAN_GENERIC)) {
-		kunit_info(test, "CONFIG_KASAN_GENERIC required");
-		return;
-	}
+	KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_GENERIC);
 
 	KUNIT_EXPECT_KASAN_FAIL(test, *(volatile char *)p);
 }

@@ -486,10 +485,7 @@ static void kasan_stack_oob(struct kunit *test)
 	volatile int i = OOB_TAG_OFF;
 	char *p = &stack_array[ARRAY_SIZE(stack_array) + i];
 
-	if (!IS_ENABLED(CONFIG_KASAN_STACK)) {
-		kunit_info(test, "CONFIG_KASAN_STACK is not enabled");
-		return;
-	}
+	KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_STACK);
 
 	KUNIT_EXPECT_KASAN_FAIL(test, *(volatile char *)p);
 }

@@ -501,15 +497,8 @@ static void kasan_alloca_oob_left(struct kunit *test)
 	char *p = alloca_array - 1;
 
 	/* Only generic mode instruments dynamic allocas. */
-	if (!IS_ENABLED(CONFIG_KASAN_GENERIC)) {
-		kunit_info(test, "CONFIG_KASAN_GENERIC required");
-		return;
-	}
-
-	if (!IS_ENABLED(CONFIG_KASAN_STACK)) {
-		kunit_info(test, "CONFIG_KASAN_STACK is not enabled");
-		return;
-	}
+	KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_GENERIC);
+	KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_STACK);
 
 	KUNIT_EXPECT_KASAN_FAIL(test, *(volatile char *)p);
 }

@@ -521,15 +510,8 @@ static void kasan_alloca_oob_right(struct kunit *test)
 	char *p = alloca_array + i;
 
 	/* Only generic mode instruments dynamic allocas. */
-	if (!IS_ENABLED(CONFIG_KASAN_GENERIC)) {
-		kunit_info(test, "CONFIG_KASAN_GENERIC required");
-		return;
-	}
-
-	if (!IS_ENABLED(CONFIG_KASAN_STACK)) {
-		kunit_info(test, "CONFIG_KASAN_STACK is not enabled");
-		return;
-	}
+	KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_GENERIC);
+	KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_STACK);
 
 	KUNIT_EXPECT_KASAN_FAIL(test, *(volatile char *)p);
 }

@@ -593,11 +575,7 @@ static void kasan_memchr(struct kunit *test)
 	 * str* functions are not instrumented with CONFIG_AMD_MEM_ENCRYPT.
 	 * See https://bugzilla.kernel.org/show_bug.cgi?id=206337 for details.
 	 */
-	if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT)) {
-		kunit_info(test,
-			"str* functions are not instrumented with CONFIG_AMD_MEM_ENCRYPT");
-		return;
-	}
+	KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_AMD_MEM_ENCRYPT);
 
 	if (OOB_TAG_OFF)
 		size = round_up(size, OOB_TAG_OFF);

@@ -621,11 +599,7 @@ static void kasan_memcmp(struct kunit *test)
 	 * str* functions are not instrumented with CONFIG_AMD_MEM_ENCRYPT.
 	 * See https://bugzilla.kernel.org/show_bug.cgi?id=206337 for details.
 	 */
-	if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT)) {
-		kunit_info(test,
-			"str* functions are not instrumented with CONFIG_AMD_MEM_ENCRYPT");
-		return;
-	}
+	KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_AMD_MEM_ENCRYPT);
 
 	if (OOB_TAG_OFF)
 		size = round_up(size, OOB_TAG_OFF);

@@ -648,11 +622,7 @@ static void kasan_strings(struct kunit *test)
 	 * str* functions are not instrumented with CONFIG_AMD_MEM_ENCRYPT.
 	 * See https://bugzilla.kernel.org/show_bug.cgi?id=206337 for details.
 	 */
-	if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT)) {
-		kunit_info(test,
-			"str* functions are not instrumented with CONFIG_AMD_MEM_ENCRYPT");
-		return;
-	}
+	KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_AMD_MEM_ENCRYPT);
 
 	ptr = kmalloc(size, GFP_KERNEL | __GFP_ZERO);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);

@@ -713,10 +683,7 @@ static void kasan_bitops_generic(struct kunit *test)
 	long *bits;
 
 	/* This test is specifically crafted for the generic mode. */
-	if (!IS_ENABLED(CONFIG_KASAN_GENERIC)) {
-		kunit_info(test, "CONFIG_KASAN_GENERIC required\n");
-		return;
-	}
+	KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_GENERIC);
 
 	/*
 	 * Allocate 1 more byte, which causes kzalloc to round up to 16 bytes;

@@ -744,11 +711,8 @@ static void kasan_bitops_tags(struct kunit *test)
 {
 	long *bits;
 
-	/* This test is specifically crafted for the tag-based mode. */
-	if (IS_ENABLED(CONFIG_KASAN_GENERIC)) {
-		kunit_info(test, "CONFIG_KASAN_SW_TAGS required\n");
-		return;
-	}
+	/* This test is specifically crafted for tag-based modes. */
+	KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC);
 
 	/* Allocation size will be rounded to up granule size, which is 16. */
 	bits = kzalloc(sizeof(*bits), GFP_KERNEL);

@@ -777,10 +741,7 @@ static void vmalloc_oob(struct kunit *test)
 {
 	void *area;
 
-	if (!IS_ENABLED(CONFIG_KASAN_VMALLOC)) {
-		kunit_info(test, "CONFIG_KASAN_VMALLOC is not enabled.");
-		return;
-	}
+	KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_VMALLOC);
 
 	/*
 	 * We have to be careful not to hit the guard page.

index 714ea27fcc3e..c344fe506ffc 100644
@@ -13,6 +13,7 @@
 #include <linux/mman.h>
 #include <linux/module.h>
 #include <linux/printk.h>
+#include <linux/random.h>
 #include <linux/slab.h>
 #include <linux/string.h>
 #include <linux/uaccess.h>

@@ -754,6 +755,94 @@ static void vmalloc_oob(struct kunit *test)
 	vfree(area);
 }
 
+/*
+ * Check that the assigned pointer tag falls within the [KASAN_TAG_MIN,
+ * KASAN_TAG_KERNEL) range (note: excluding the match-all tag) for tag-based
+ * modes.
+ */
+static void match_all_not_assigned(struct kunit *test)
+{
+	char *ptr;
+	struct page *pages;
+	int i, size, order;
+
+	KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC);
+
+	for (i = 0; i < 256; i++) {
+		size = (get_random_int() % 1024) + 1;
+		ptr = kmalloc(size, GFP_KERNEL);
+		KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
+		KUNIT_EXPECT_GE(test, (u8)get_tag(ptr), (u8)KASAN_TAG_MIN);
+		KUNIT_EXPECT_LT(test, (u8)get_tag(ptr), (u8)KASAN_TAG_KERNEL);
+		kfree(ptr);
+	}
+
+	for (i = 0; i < 256; i++) {
+		order = (get_random_int() % 4) + 1;
+		pages = alloc_pages(GFP_KERNEL, order);
+		ptr = page_address(pages);
+		KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
+		KUNIT_EXPECT_GE(test, (u8)get_tag(ptr), (u8)KASAN_TAG_MIN);
+		KUNIT_EXPECT_LT(test, (u8)get_tag(ptr), (u8)KASAN_TAG_KERNEL);
+		free_pages((unsigned long)ptr, order);
+	}
+}
+
+/* Check that 0xff works as a match-all pointer tag for tag-based modes. */
+static void match_all_ptr_tag(struct kunit *test)
+{
+	char *ptr;
+	u8 tag;
+
+	KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC);
+
+	ptr = kmalloc(128, GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
+
+	/* Backup the assigned tag. */
+	tag = get_tag(ptr);
+	KUNIT_EXPECT_NE(test, tag, (u8)KASAN_TAG_KERNEL);
+
+	/* Reset the tag to 0xff.*/
+	ptr = set_tag(ptr, KASAN_TAG_KERNEL);
+
+	/* This access shouldn't trigger a KASAN report. */
+	*ptr = 0;
+
+	/* Recover the pointer tag and free. */
+	ptr = set_tag(ptr, tag);
+	kfree(ptr);
+}
+
+/* Check that there are no match-all memory tags for tag-based modes. */
+static void match_all_mem_tag(struct kunit *test)
+{
+	char *ptr;
+	int tag;
+
+	KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC);
+
+	ptr = kmalloc(128, GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
+	KUNIT_EXPECT_NE(test, (u8)get_tag(ptr), (u8)KASAN_TAG_KERNEL);
+
+	/* For each possible tag value not matching the pointer tag. */
+	for (tag = KASAN_TAG_MIN; tag <= KASAN_TAG_KERNEL; tag++) {
+		if (tag == get_tag(ptr))
+			continue;
+
+		/* Mark the first memory granule with the chosen memory tag. */
+		kasan_poison(ptr, KASAN_GRANULE_SIZE, (u8)tag);
+
+		/* This access must cause a KASAN report. */
+		KUNIT_EXPECT_KASAN_FAIL(test, *ptr = 0);
+	}
+
+	/* Recover the memory tag and free. */
+	kasan_poison(ptr, KASAN_GRANULE_SIZE, get_tag(ptr));
+	kfree(ptr);
+}
+
 static struct kunit_case kasan_kunit_test_cases[] = {
 	KUNIT_CASE(kmalloc_oob_right),
 	KUNIT_CASE(kmalloc_oob_left),

@@ -793,6 +882,9 @@ static struct kunit_case kasan_kunit_test_cases[] = {
 	KUNIT_CASE(kasan_bitops_tags),
 	KUNIT_CASE(kmalloc_double_kzfree),
 	KUNIT_CASE(vmalloc_oob),
+	KUNIT_CASE(match_all_not_assigned),
+	KUNIT_CASE(match_all_ptr_tag),
+	KUNIT_CASE(match_all_mem_tag),
 	{}
 };
 

index 3b38baddec47..c3fb9bf241d3 100644
@@ -36,6 +36,12 @@ extern bool kasan_flag_panic __ro_after_init;
 #define KASAN_TAG_INVALID	0xFE /* inaccessible memory tag */
 #define KASAN_TAG_MAX		0xFD /* maximum value for random tags */
 
+#ifdef CONFIG_KASAN_HW_TAGS
+#define KASAN_TAG_MIN		0xF0 /* mimimum value for random tags */
+#else
+#define KASAN_TAG_MIN		0x00 /* mimimum value for random tags */
+#endif
+
 #ifdef CONFIG_KASAN_GENERIC
 #define KASAN_FREE_PAGE         0xFF  /* page was freed */
 #define KASAN_PAGE_REDZONE      0xFE  /* redzone for kmalloc_large allocations */

index 18fce223b67b..cedfc9e97bcc 100644
@@ -232,6 +232,7 @@ static inline const void *__tag_set(const void *addr, u8 tag)
 
 #ifdef CONFIG_KASAN_HW_TAGS
 #define arch_enable_tagging()			mte_enable_kernel()
+#define arch_set_tagging_report_once(state)	mte_set_report_once(state)
 #define arch_init_tags(max_tag)			mte_init_tags(max_tag)
 #define arch_get_random_tag()			mte_get_random_tag()
 #define arch_get_mem_tag(addr)			mte_get_mem_tag(addr)

index 26349a4b5e2e..3748d5bb88c0 100644
@@ -32,6 +32,9 @@ void *mte_set_mem_tag_range(void *addr, size_t size, u8 tag);
 void mte_enable_kernel(void);
 void mte_init_tags(u64 max_tag);
 
+void mte_set_report_once(bool state);
+bool mte_report_once(void);
+
 #else /* CONFIG_ARM64_MTE */
 
 static inline u8 mte_get_ptr_tag(void *ptr)

@@ -60,6 +63,15 @@ static inline void mte_init_tags(u64 max_tag)
 {
 }
 
+static inline void mte_set_report_once(bool state)
+{
+}
+
+static inline bool mte_report_once(void)
+{
+	return false;
+}
+
 #endif /* CONFIG_ARM64_MTE */
 
 #endif /* __ASSEMBLY__ */

index dc9ada64feed..c63b3d7a3cd9 100644
@@ -25,6 +25,8 @@
 
 u64 gcr_kernel_excl __ro_after_init;
 
+static bool report_fault_once = true;
+
 static void mte_sync_page_tags(struct page *page, pte_t *ptep, bool check_swap)
 {
 	pte_t old_pte = READ_ONCE(*ptep);

@@ -158,6 +160,16 @@ void mte_enable_kernel(void)
 	isb();
 }
 
+void mte_set_report_once(bool state)
+{
+	WRITE_ONCE(report_fault_once, state);
+}
+
+bool mte_report_once(void)
+{
+	return READ_ONCE(report_fault_once);
+}
+
 static void update_sctlr_el1_tcf0(u64 tcf0)
 {
 	/* ISB required for the kernel uaccess routines */

index a218f6f2fdc8..f1b77dc79948 100644
@@ -302,7 +302,14 @@ static void die_kernel_fault(const char *msg, unsigned long addr,
 static void report_tag_fault(unsigned long addr, unsigned int esr,
 			     struct pt_regs *regs)
 {
-	bool is_write  = ((esr & ESR_ELx_WNR) >> ESR_ELx_WNR_SHIFT) != 0;
+	static bool reported;
+	bool is_write;
+
+	if (READ_ONCE(reported))
+		return;
+
+	if (mte_report_once())
+		WRITE_ONCE(reported, true);
 
 	/* The format of KASAN tags is 0xF<x>. */
 	addr |= (0xF0UL << MTE_TAG_SHIFT);

@@ -310,6 +317,7 @@ static void report_tag_fault(unsigned long addr, unsigned int esr,
 	 * SAS bits aren't set for all faults reported in EL1, so we can't
 	 * find out access size.
 	 */
+	is_write = ((esr & ESR_ELx_WNR) >> ESR_ELx_WNR_SHIFT) != 0;
 	kasan_report(addr, 0, is_write, regs->pc);
 }
 #else

@@ -321,12 +329,8 @@ static inline void report_tag_fault(unsigned long addr, unsigned int esr,
 static void do_tag_recovery(unsigned long addr, unsigned int esr,
 			   struct pt_regs *regs)
 {
-	static bool reported;
 
-	if (!READ_ONCE(reported)) {
-		report_tag_fault(addr, esr, regs);
-		WRITE_ONCE(reported, true);
-	}
+	report_tag_fault(addr, esr, regs);
 
 	/*
 	 * Disable MTE Tag Checking on the local CPU for the current EL.

64 lines not on this page · raw message

index c3fb9bf241d3..292dfbc37deb 100644
@@ -280,6 +280,9 @@ static inline const void *arch_kasan_set_tag(const void *addr, u8 tag)
 #ifndef arch_init_tags
 #define arch_init_tags(max_tag)
 #endif
+#ifndef arch_set_tagging_report_once
+#define arch_set_tagging_report_once(state)
+#endif
 #ifndef arch_get_random_tag
 #define arch_get_random_tag()	(0xFF)
 #endif

@@ -292,10 +295,16 @@ static inline const void *arch_kasan_set_tag(const void *addr, u8 tag)
 
 #define hw_enable_tagging()			arch_enable_tagging()
 #define hw_init_tags(max_tag)			arch_init_tags(max_tag)
+#define hw_set_tagging_report_once(state)	arch_set_tagging_report_once(state)
 #define hw_get_random_tag()			arch_get_random_tag()
 #define hw_get_mem_tag(addr)			arch_get_mem_tag(addr)
 #define hw_set_mem_tag_range(addr, size, tag)	arch_set_mem_tag_range((addr), (size), (tag))
 
+#else /* CONFIG_KASAN_HW_TAGS */
+
+#define hw_enable_tagging()
+#define hw_set_tagging_report_once(state)
+
 #endif /* CONFIG_KASAN_HW_TAGS */
 
 #ifdef CONFIG_KASAN_SW_TAGS

index ef663bcf83e5..2419e36e117b 100644
@@ -68,23 +68,30 @@ static void kasan_test_exit(struct kunit *test)
  * normally auto-disabled. When this happens, this test handler reenables
  * tag checking. As tag checking can be only disabled or enabled per CPU, this
  * handler disables migration (preemption).
+ *
+ * Since the compiler doesn't see that the expression can change the fail_data
+ * fields, it can reorder or optimize away the accesses to those fields.
+ * Use READ/WRITE_ONCE() for the accesses and compiler barriers around the
+ * expression to prevent that.
  */
 #define KUNIT_EXPECT_KASAN_FAIL(test, expression) do {		\
 	if (IS_ENABLED(CONFIG_KASAN_HW_TAGS))			\
 		migrate_disable();				\
-	fail_data.report_expected = true;			\
-	fail_data.report_found = false;				\
+	WRITE_ONCE(fail_data.report_expected, true);		\
+	WRITE_ONCE(fail_data.report_found, false);		\
 	kunit_add_named_resource(test,				\
 				NULL,				\
 				NULL,				\
 				&resource,			\
 				"kasan_data", &fail_data);	\
+	barrier();						\
 	expression;						\
+	barrier();						\
 	KUNIT_EXPECT_EQ(test,					\
-			fail_data.report_expected,		\
-			fail_data.report_found);		\
+			READ_ONCE(fail_data.report_expected),	\
+			READ_ONCE(fail_data.report_found));	\
 	if (IS_ENABLED(CONFIG_KASAN_HW_TAGS)) {			\
-		if (fail_data.report_found)			\
+		if (READ_ONCE(fail_data.report_found))		\
 			hw_enable_tagging();			\
 		migrate_enable();				\
 	}							\

index e93d7973792e..234f35a84f19 100644
@@ -331,7 +331,7 @@ static void kasan_update_kunit_status(struct kunit *cur_test)
 	}
 
 	kasan_data = (struct kunit_kasan_expectation *)resource->data;
-	kasan_data->report_found = true;
+	WRITE_ONCE(kasan_data->report_found, true);
 	kunit_put_resource(resource);
 }
 #endif /* IS_ENABLED(CONFIG_KUNIT) */

index 2419e36e117b..0cda4a1ff394 100644
@@ -382,7 +382,9 @@ static void kmalloc_uaf2(struct kunit *test)
 {
 	char *ptr1, *ptr2;
 	size_t size = 43;
+	int counter = 0;
 
+again:
 	ptr1 = kmalloc(size, GFP_KERNEL);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1);
 

@@ -391,6 +393,15 @@ static void kmalloc_uaf2(struct kunit *test)
 	ptr2 = kmalloc(size, GFP_KERNEL);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr2);
 
+	/*
+	 * For tag-based KASAN ptr1 and ptr2 tags might happen to be the same.
+	 * Allow up to 16 attempts at generating different tags.
+	 */
+	if (!IS_ENABLED(CONFIG_KASAN_GENERIC) && ptr1 == ptr2 && counter++ < 16) {
+		kfree(ptr2);
+		goto again;
+	}
+
 	KUNIT_EXPECT_KASAN_FAIL(test, ptr1[40] = 'x');
 	KUNIT_EXPECT_PTR_NE(test, ptr1, ptr2);
 

index 0cda4a1ff394..a06e7946f581 100644
@@ -749,13 +749,13 @@ static void kasan_bitops_tags(struct kunit *test)
 	/* This test is specifically crafted for tag-based modes. */
 	KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC);
 
-	/* Allocation size will be rounded to up granule size, which is 16. */
-	bits = kzalloc(sizeof(*bits), GFP_KERNEL);
+	/* kmalloc-64 cache will be used and the last 16 bytes will be the redzone. */
+	bits = kzalloc(48, GFP_KERNEL);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, bits);
 
-	/* Do the accesses past the 16 allocated bytes. */
-	kasan_bitops_modify(test, BITS_PER_LONG, &bits[1]);
-	kasan_bitops_test_and_modify(test, BITS_PER_LONG + BITS_PER_BYTE, &bits[1]);
+	/* Do the accesses past the 48 allocated bytes, but within the redone. */
+	kasan_bitops_modify(test, BITS_PER_LONG, (void *)bits + 48);
+	kasan_bitops_test_and_modify(test, BITS_PER_LONG + BITS_PER_BYTE, (void *)bits + 48);
 
 	kfree(bits);
 }

index 5e0655fb2a6f..bba1637827c3 100644
@@ -181,19 +181,18 @@ static __always_inline void * __must_check kasan_init_slab_obj(
 }
 
 bool __kasan_slab_free(struct kmem_cache *s, void *object, unsigned long ip);
-static __always_inline bool kasan_slab_free(struct kmem_cache *s, void *object,
-						unsigned long ip)
+static __always_inline bool kasan_slab_free(struct kmem_cache *s, void *object)
 {
 	if (kasan_enabled())
-		return __kasan_slab_free(s, object, ip);
+		return __kasan_slab_free(s, object, _RET_IP_);
 	return false;
 }
 
 void __kasan_slab_free_mempool(void *ptr, unsigned long ip);
-static __always_inline void kasan_slab_free_mempool(void *ptr, unsigned long ip)
+static __always_inline void kasan_slab_free_mempool(void *ptr)
 {
 	if (kasan_enabled())
-		__kasan_slab_free_mempool(ptr, ip);
+		__kasan_slab_free_mempool(ptr, _RET_IP_);
 }
 
 void * __must_check __kasan_slab_alloc(struct kmem_cache *s,

@@ -237,10 +236,10 @@ static __always_inline void * __must_check kasan_krealloc(const void *object,
 }
 
 void __kasan_kfree_large(void *ptr, unsigned long ip);
-static __always_inline void kasan_kfree_large(void *ptr, unsigned long ip)
+static __always_inline void kasan_kfree_large(void *ptr)
 {
 	if (kasan_enabled())
-		__kasan_kfree_large(ptr, ip);
+		__kasan_kfree_large(ptr, _RET_IP_);
 }
 
 bool kasan_save_enable_multi_shot(void);

@@ -273,12 +272,11 @@ static inline void *kasan_init_slab_obj(struct kmem_cache *cache,
 {
 	return (void *)object;
 }
-static inline bool kasan_slab_free(struct kmem_cache *s, void *object,
-				   unsigned long ip)
+static inline bool kasan_slab_free(struct kmem_cache *s, void *object)
 {
 	return false;
 }
-static inline void kasan_slab_free_mempool(void *ptr, unsigned long ip) {}
+static inline void kasan_slab_free_mempool(void *ptr) {}
 static inline void *kasan_slab_alloc(struct kmem_cache *s, void *object,
 				   gfp_t flags)
 {

@@ -298,7 +296,7 @@ static inline void *kasan_krealloc(const void *object, size_t new_size,
 {
 	return (void *)object;
 }
-static inline void kasan_kfree_large(void *ptr, unsigned long ip) {}
+static inline void kasan_kfree_large(void *ptr) {}
 
 #endif /* CONFIG_KASAN */
 

index 624ed51b060f..79959fac27d7 100644
@@ -104,7 +104,7 @@ static inline void poison_element(mempool_t *pool, void *element)
 static __always_inline void kasan_poison_element(mempool_t *pool, void *element)
 {
 	if (pool->alloc == mempool_alloc_slab || pool->alloc == mempool_kmalloc)
-		kasan_slab_free_mempool(element, _RET_IP_);
+		kasan_slab_free_mempool(element);
 	else if (pool->alloc == mempool_alloc_pages)
 		kasan_free_pages(element, (unsigned long)pool->pool_data);
 }

index d7c8da9319c7..afeb6191fb1e 100644
@@ -3421,7 +3421,7 @@ static __always_inline void __cache_free(struct kmem_cache *cachep, void *objp,
 		memset(objp, 0, cachep->object_size);
 
 	/* Put the object into the quarantine, don't touch it for now. */
-	if (kasan_slab_free(cachep, objp, _RET_IP_))
+	if (kasan_slab_free(cachep, objp))
 		return;
 
 	/* Use KCSAN to help debug racy use-after-free. */

index 75fb097d990d..0afb53488238 100644
@@ -1514,7 +1514,7 @@ static inline void *kmalloc_large_node_hook(void *ptr, size_t size, gfp_t flags)
 static __always_inline void kfree_hook(void *x)
 {
 	kmemleak_free(x);
-	kasan_kfree_large(x, _RET_IP_);
+	kasan_kfree_large(x);
 }
 
 static __always_inline bool slab_free_hook(struct kmem_cache *s, void *x)

@@ -1544,7 +1544,7 @@ static __always_inline bool slab_free_hook(struct kmem_cache *s, void *x)
 				     KCSAN_ACCESS_WRITE | KCSAN_ACCESS_ASSERT);
 
 	/* KASAN might put x into memory quarantine, delaying its reuse */
-	return kasan_slab_free(s, x, _RET_IP_);
+	return kasan_slab_free(s, x);
 }
 
 static inline bool slab_free_freelist_hook(struct kmem_cache *s,

index ca5e89fb10d3..3d6d22a25bdc 100644
@@ -4,6 +4,12 @@
 
 #include <linux/types.h>
 
+/*
+ * The annotations present in this file are only relevant for the software
+ * KASAN modes that rely on compiler instrumentation, and will be optimized
+ * away for the hardware tag-based KASAN mode. Use kasan_check_byte() instead.
+ */
+
 /*
  * __kasan_check_*: Always available when KASAN is enabled. This may be used
  * even in compilation units that selectively disable KASAN, but must use KASAN

index bba1637827c3..5bedd5ee481f 100644
@@ -242,6 +242,19 @@ static __always_inline void kasan_kfree_large(void *ptr)
 		__kasan_kfree_large(ptr, _RET_IP_);
 }
 
+/*
+ * Unlike kasan_check_read/write(), kasan_check_byte() is performed even for
+ * the hardware tag-based mode that doesn't rely on compiler instrumentation.
+ */
+bool __kasan_check_byte(const void *addr, unsigned long ip);
+static __always_inline bool kasan_check_byte(const void *addr)
+{
+	if (kasan_enabled())
+		return __kasan_check_byte(addr, _RET_IP_);
+	return true;
+}
+
+
 bool kasan_save_enable_multi_shot(void);
 void kasan_restore_multi_shot(bool enabled);
 

@@ -297,6 +310,10 @@ static inline void *kasan_krealloc(const void *object, size_t new_size,
 	return (void *)object;
 }
 static inline void kasan_kfree_large(void *ptr) {}
+static inline bool kasan_check_byte(const void *address)
+{
+	return true;
+}
 
 #endif /* CONFIG_KASAN */
 

index a06e7946f581..566d894ba20b 100644
@@ -496,6 +496,7 @@ static void kasan_global_oob(struct kunit *test)
 	KUNIT_EXPECT_KASAN_FAIL(test, *(volatile char *)p);
 }
 
+/* Check that ksize() makes the whole object accessible. */
 static void ksize_unpoisons_memory(struct kunit *test)
 {
 	char *ptr;

@@ -514,6 +515,24 @@ static void ksize_unpoisons_memory(struct kunit *test)
 	kfree(ptr);
 }
 
+/*
+ * Check that a use-after-free is detected by ksize() and via normal accesses
+ * after it.
+ */
+static void ksize_uaf(struct kunit *test)
+{
+	char *ptr;
+	int size = 128 - KASAN_GRANULE_SIZE;
+
+	ptr = kmalloc(size, GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
+	kfree(ptr);
+
+	KUNIT_EXPECT_KASAN_FAIL(test, ksize(ptr));
+	KUNIT_EXPECT_KASAN_FAIL(test, kasan_int_result = *ptr);
+	KUNIT_EXPECT_KASAN_FAIL(test, kasan_int_result = *(ptr + size));
+}
+
 static void kasan_stack_oob(struct kunit *test)
 {
 	char stack_array[10];

@@ -907,6 +926,7 @@ static struct kunit_case kasan_kunit_test_cases[] = {
 	KUNIT_CASE(kasan_alloca_oob_left),
 	KUNIT_CASE(kasan_alloca_oob_right),
 	KUNIT_CASE(ksize_unpoisons_memory),
+	KUNIT_CASE(ksize_uaf),
 	KUNIT_CASE(kmem_cache_double_free),
 	KUNIT_CASE(kmem_cache_invalid_free),
 	KUNIT_CASE(kasan_memchr),

index eedc3e0fe365..b18189ef3a92 100644
@@ -345,7 +345,7 @@ static bool ____kasan_slab_free(struct kmem_cache *cache, void *object,
 	if (unlikely(cache->flags & SLAB_TYPESAFE_BY_RCU))
 		return false;
 
-	if (kasan_check_invalid_free(tagged_object)) {
+	if (!kasan_byte_accessible(tagged_object)) {
 		kasan_report_invalid_free(tagged_object, ip);
 		return true;
 	}

@@ -490,3 +490,12 @@ void __kasan_kfree_large(void *ptr, unsigned long ip)
 		kasan_report_invalid_free(ptr, ip);
 	/* The object will be poisoned by kasan_free_pages(). */
 }
+
+bool __kasan_check_byte(const void *address, unsigned long ip)
+{
+	if (!kasan_byte_accessible(address)) {
+		kasan_report((unsigned long)address, 1, false, ip);
+		return false;
+	}
+	return true;
+}

index acab8862dc67..3f17a1218055 100644
@@ -185,11 +185,11 @@ bool kasan_check_range(unsigned long addr, size_t size, bool write,
 	return check_region_inline(addr, size, write, ret_ip);
 }
 
-bool kasan_check_invalid_free(void *addr)
+bool kasan_byte_accessible(const void *addr)
 {
 	s8 shadow_byte = READ_ONCE(*(s8 *)kasan_mem_to_shadow(addr));
 
-	return shadow_byte < 0 || shadow_byte >= KASAN_GRANULE_SIZE;
+	return shadow_byte >= 0 && shadow_byte < KASAN_GRANULE_SIZE;
 }
 
 void kasan_cache_shrink(struct kmem_cache *cache)

index 292dfbc37deb..bd4ee6fab648 100644
@@ -329,20 +329,20 @@ static inline void kasan_unpoison(const void *address, size_t size)
 			round_up(size, KASAN_GRANULE_SIZE), get_tag(address));
 }
 
-static inline bool kasan_check_invalid_free(void *addr)
+static inline bool kasan_byte_accessible(const void *addr)
 {
 	u8 ptr_tag = get_tag(addr);
-	u8 mem_tag = hw_get_mem_tag(addr);
+	u8 mem_tag = hw_get_mem_tag((void *)addr);
 
-	return (mem_tag == KASAN_TAG_INVALID) ||
-		(ptr_tag != KASAN_TAG_KERNEL && ptr_tag != mem_tag);
+	return (mem_tag != KASAN_TAG_INVALID) &&
+		(ptr_tag == KASAN_TAG_KERNEL || ptr_tag == mem_tag);
 }
 
 #else /* CONFIG_KASAN_HW_TAGS */
 
 void kasan_poison(const void *address, size_t size, u8 value);
 void kasan_unpoison(const void *address, size_t size);
-bool kasan_check_invalid_free(void *addr);
+bool kasan_byte_accessible(const void *addr);
 
 #endif /* CONFIG_KASAN_HW_TAGS */
 

index cc271fceb5d5..94c2d33be333 100644
@@ -118,13 +118,13 @@ bool kasan_check_range(unsigned long addr, size_t size, bool write,
 	return true;
 }
 
-bool kasan_check_invalid_free(void *addr)
+bool kasan_byte_accessible(const void *addr)
 {
 	u8 tag = get_tag(addr);
 	u8 shadow_byte = READ_ONCE(*(u8 *)kasan_mem_to_shadow(kasan_reset_tag(addr)));
 
-	return (shadow_byte == KASAN_TAG_INVALID) ||
-		(tag != KASAN_TAG_KERNEL && tag != shadow_byte);
+	return (shadow_byte != KASAN_TAG_INVALID) &&
+		(tag == KASAN_TAG_KERNEL || tag == shadow_byte);
 }
 
 #define DEFINE_HWASAN_LOAD_STORE(size)					\

index e981c80d216c..9c12cf4212ea 100644
@@ -1157,19 +1157,21 @@ size_t ksize(const void *objp)
 	size_t size;
 
 	/*
-	 * We need to check that the pointed to object is valid, and only then
-	 * unpoison the shadow memory below. We use __kasan_check_read(), to
-	 * generate a more useful report at the time ksize() is called (rather
-	 * than later where behaviour is undefined due to potential
-	 * use-after-free or double-free).
+	 * We need to first check that the pointer to the object is valid, and
+	 * only then unpoison the memory. The report printed from ksize() is
+	 * more useful, then when it's printed later when the behaviour could
+	 * be undefined due to a potential use-after-free or double-free.
 	 *
-	 * If the pointed to memory is invalid we return 0, to avoid users of
+	 * We use kasan_check_byte(), which is supported for the hardware
+	 * tag-based KASAN mode, unlike kasan_check_read/write().
+	 *
+	 * If the pointed to memory is invalid, we return 0 to avoid users of
 	 * ksize() writing to and potentially corrupting the memory region.
 	 *
 	 * We want to perform the check before __ksize(), to avoid potentially
 	 * crashing in __ksize() due to accessing invalid metadata.
 	 */
-	if (unlikely(ZERO_OR_NULL_PTR(objp)) || !__kasan_check_read(objp, 1))
+	if (unlikely(ZERO_OR_NULL_PTR(objp)) || !kasan_check_byte(objp))
 		return 0;
 
 	size = __ksize(objp);

index 566d894ba20b..ab22a653762e 100644
@@ -147,6 +147,12 @@ static void kmalloc_node_oob_right(struct kunit *test)
 	kfree(ptr);
 }
 
+/*
+ * These kmalloc_pagealloc_* tests try allocating a memory chunk that doesn't
+ * fit into a slab cache and therefore is allocated via the page allocator
+ * fallback. Since this kind of fallback is only implemented for SLUB, these
+ * tests are limited to that allocator.
+ */
 static void kmalloc_pagealloc_oob_right(struct kunit *test)
 {
 	char *ptr;

@@ -154,14 +160,11 @@ static void kmalloc_pagealloc_oob_right(struct kunit *test)
 
 	KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_SLUB);
 
-	/*
-	 * Allocate a chunk that does not fit into a SLUB cache to trigger
-	 * the page allocator fallback.
-	 */
 	ptr = kmalloc(size, GFP_KERNEL);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
 
 	KUNIT_EXPECT_KASAN_FAIL(test, ptr[size + OOB_TAG_OFF] = 0);
+
 	kfree(ptr);
 }
 

@@ -174,8 +177,8 @@ static void kmalloc_pagealloc_uaf(struct kunit *test)
 
 	ptr = kmalloc(size, GFP_KERNEL);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
-
 	kfree(ptr);
+
 	KUNIT_EXPECT_KASAN_FAIL(test, ptr[0] = 0);
 }
 

@@ -192,6 +195,42 @@ static void kmalloc_pagealloc_invalid_free(struct kunit *test)
 	KUNIT_EXPECT_KASAN_FAIL(test, kfree(ptr + 1));
 }
 
+static void pagealloc_oob_right(struct kunit *test)
+{
+	char *ptr;
+	struct page *pages;
+	size_t order = 4;
+	size_t size = (1UL << (PAGE_SHIFT + order));
+
+	/*
+	 * With generic KASAN page allocations have no redzones, thus
+	 * out-of-bounds detection is not guaranteed.
+	 * See https://bugzilla.kernel.org/show_bug.cgi?id=210503.
+	 */
+	KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC);
+
+	pages = alloc_pages(GFP_KERNEL, order);
+	ptr = page_address(pages);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
+
+	KUNIT_EXPECT_KASAN_FAIL(test, ptr[size] = 0);
+	free_pages((unsigned long)ptr, order);
+}
+
+static void pagealloc_uaf(struct kunit *test)
+{
+	char *ptr;
+	struct page *pages;
+	size_t order = 4;
+
+	pages = alloc_pages(GFP_KERNEL, order);
+	ptr = page_address(pages);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
+	free_pages((unsigned long)ptr, order);
+
+	KUNIT_EXPECT_KASAN_FAIL(test, ptr[0] = 0);
+}
+
 static void kmalloc_large_oob_right(struct kunit *test)
 {
 	char *ptr;

@@ -903,6 +942,8 @@ static struct kunit_case kasan_kunit_test_cases[] = {
 	KUNIT_CASE(kmalloc_pagealloc_oob_right),
 	KUNIT_CASE(kmalloc_pagealloc_uaf),
 	KUNIT_CASE(kmalloc_pagealloc_invalid_free),
+	KUNIT_CASE(pagealloc_oob_right),
+	KUNIT_CASE(pagealloc_uaf),
 	KUNIT_CASE(kmalloc_large_oob_right),
 	KUNIT_CASE(kmalloc_oob_krealloc_more),
 	KUNIT_CASE(kmalloc_oob_krealloc_less),

index ab22a653762e..a96376aa7293 100644
@@ -479,10 +479,11 @@ static void kmem_cache_oob(struct kunit *test)
 {
 	char *p;
 	size_t size = 200;
-	struct kmem_cache *cache = kmem_cache_create("test_cache",
-						size, 0,
-						0, NULL);
+	struct kmem_cache *cache;
+
+	cache = kmem_cache_create("test_cache",	size, 0, 0, NULL);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cache);
+
 	p = kmem_cache_alloc(cache, GFP_KERNEL);
 	if (!p) {
 		kunit_err(test, "Allocation failed: %s\n", __func__);

@@ -491,11 +492,12 @@ static void kmem_cache_oob(struct kunit *test)
 	}
 
 	KUNIT_EXPECT_KASAN_FAIL(test, *p = p[size + OOB_TAG_OFF]);
+
 	kmem_cache_free(cache, p);
 	kmem_cache_destroy(cache);
 }
 
-static void memcg_accounted_kmem_cache(struct kunit *test)
+static void kmem_cache_accounted(struct kunit *test)
 {
 	int i;
 	char *p;

@@ -522,6 +524,31 @@ static void memcg_accounted_kmem_cache(struct kunit *test)
 	kmem_cache_destroy(cache);
 }
 
+static void kmem_cache_bulk(struct kunit *test)
+{
+	struct kmem_cache *cache;
+	size_t size = 200;
+	char *p[10];
+	bool ret;
+	int i;
+
+	cache = kmem_cache_create("test_cache",	size, 0, 0, NULL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cache);
+
+	ret = kmem_cache_alloc_bulk(cache, GFP_KERNEL, ARRAY_SIZE(p), (void **)&p);
+	if (!ret) {
+		kunit_err(test, "Allocation failed: %s\n", __func__);
+		kmem_cache_destroy(cache);
+		return;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(p); i++)
+		p[i][0] = p[i][size - 1] = 42;
+
+	kmem_cache_free_bulk(cache, ARRAY_SIZE(p), (void **)&p);
+	kmem_cache_destroy(cache);
+}
+
 static char global_array[10];
 
 static void kasan_global_oob(struct kunit *test)

@@ -961,7 +988,8 @@ static struct kunit_case kasan_kunit_test_cases[] = {
 	KUNIT_CASE(kfree_via_page),
 	KUNIT_CASE(kfree_via_phys),
 	KUNIT_CASE(kmem_cache_oob),
-	KUNIT_CASE(memcg_accounted_kmem_cache),
+	KUNIT_CASE(kmem_cache_accounted),
+	KUNIT_CASE(kmem_cache_bulk),
 	KUNIT_CASE(kasan_global_oob),
 	KUNIT_CASE(kasan_stack_oob),
 	KUNIT_CASE(kasan_alloca_oob_left),

index a96376aa7293..6238b56127f8 100644
@@ -47,6 +47,11 @@ static bool multishot;
  */
 static int kasan_test_init(struct kunit *test)
 {
+	if (!kasan_enabled()) {
+		kunit_err(test, "can't run KASAN tests with KASAN disabled");
+		return -1;
+	}
+
 	multishot = kasan_save_enable_multi_shot();
 	hw_set_tagging_report_once(false);
 	return 0;