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-rw-r--r--mm/kasan/common.c291
-rw-r--r--mm/kasan/generic.c130
-rw-r--r--mm/kasan/hw_tags.c8
-rw-r--r--mm/kasan/kasan.h86
-rw-r--r--mm/kasan/kasan_test.c793
-rw-r--r--mm/kasan/quarantine.c20
-rw-r--r--mm/kasan/report.c47
-rw-r--r--mm/kasan/report_generic.c6
-rw-r--r--mm/kasan/report_tags.c27
-rw-r--r--mm/kasan/shadow.c18
-rw-r--r--mm/kasan/tags.c24
11 files changed, 972 insertions, 478 deletions
diff --git a/mm/kasan/common.c b/mm/kasan/common.c
index 256930da578a..6ca63e8dda74 100644
--- a/mm/kasan/common.c
+++ b/mm/kasan/common.c
@@ -20,8 +20,10 @@
#include <linux/module.h>
#include <linux/printk.h>
#include <linux/sched.h>
+#include <linux/sched/clock.h>
#include <linux/sched/task_stack.h>
#include <linux/slab.h>
+#include <linux/stackdepot.h>
#include <linux/stacktrace.h>
#include <linux/string.h>
#include <linux/types.h>
@@ -37,19 +39,34 @@ struct slab *kasan_addr_to_slab(const void *addr)
return NULL;
}
-depot_stack_handle_t kasan_save_stack(gfp_t flags, bool can_alloc)
+depot_stack_handle_t kasan_save_stack(gfp_t flags, depot_flags_t depot_flags)
{
unsigned long entries[KASAN_STACK_DEPTH];
unsigned int nr_entries;
nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 0);
- return __stack_depot_save(entries, nr_entries, flags, can_alloc);
+ return stack_depot_save_flags(entries, nr_entries, flags, depot_flags);
}
-void kasan_set_track(struct kasan_track *track, gfp_t flags)
+void kasan_set_track(struct kasan_track *track, depot_stack_handle_t stack)
{
+#ifdef CONFIG_KASAN_EXTRA_INFO
+ u32 cpu = raw_smp_processor_id();
+ u64 ts_nsec = local_clock();
+
+ track->cpu = cpu;
+ track->timestamp = ts_nsec >> 3;
+#endif /* CONFIG_KASAN_EXTRA_INFO */
track->pid = current->pid;
- track->stack = kasan_save_stack(flags, true);
+ track->stack = stack;
+}
+
+void kasan_save_track(struct kasan_track *track, gfp_t flags)
+{
+ depot_stack_handle_t stack;
+
+ stack = kasan_save_stack(flags, STACK_DEPOT_FLAG_CAN_ALLOC);
+ kasan_set_track(track, stack);
}
#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
@@ -69,6 +86,9 @@ EXPORT_SYMBOL(kasan_disable_current);
void __kasan_unpoison_range(const void *address, size_t size)
{
+ if (is_kfence_address(address))
+ return;
+
kasan_unpoison(address, size, false);
}
@@ -133,12 +153,12 @@ void __kasan_poison_slab(struct slab *slab)
KASAN_SLAB_REDZONE, false);
}
-void __kasan_unpoison_object_data(struct kmem_cache *cache, void *object)
+void __kasan_unpoison_new_object(struct kmem_cache *cache, void *object)
{
kasan_unpoison(object, cache->object_size, false);
}
-void __kasan_poison_object_data(struct kmem_cache *cache, void *object)
+void __kasan_poison_new_object(struct kmem_cache *cache, void *object)
{
kasan_poison(object, round_up(cache->object_size, KASAN_GRANULE_SIZE),
KASAN_SLAB_REDZONE, false);
@@ -153,10 +173,6 @@ void __kasan_poison_object_data(struct kmem_cache *cache, void *object)
* 2. A cache might be SLAB_TYPESAFE_BY_RCU, which means objects can be
* accessed after being freed. We preassign tags for objects in these
* caches as well.
- * 3. For SLAB allocator we can't preassign tags randomly since the freelist
- * is stored as an array of indexes instead of a linked list. Assign tags
- * based on objects indexes, so that objects that are next to each other
- * get different tags.
*/
static inline u8 assign_tag(struct kmem_cache *cache,
const void *object, bool init)
@@ -171,17 +187,12 @@ static inline u8 assign_tag(struct kmem_cache *cache,
if (!cache->ctor && !(cache->flags & SLAB_TYPESAFE_BY_RCU))
return init ? KASAN_TAG_KERNEL : kasan_random_tag();
- /* For caches that either have a constructor or SLAB_TYPESAFE_BY_RCU: */
-#ifdef CONFIG_SLAB
- /* For SLAB assign tags based on the object index in the freelist. */
- return (u8)obj_to_index(cache, virt_to_slab(object), (void *)object);
-#else
/*
- * For SLUB assign a random tag during slab creation, otherwise reuse
+ * For caches that either have a constructor or SLAB_TYPESAFE_BY_RCU,
+ * assign a random tag during slab creation, otherwise reuse
* the already assigned tag.
*/
return init ? kasan_random_tag() : get_tag(object);
-#endif
}
void * __must_check __kasan_init_slab_obj(struct kmem_cache *cache,
@@ -197,8 +208,8 @@ void * __must_check __kasan_init_slab_obj(struct kmem_cache *cache,
return (void *)object;
}
-static inline bool ____kasan_slab_free(struct kmem_cache *cache, void *object,
- unsigned long ip, bool quarantine, bool init)
+static inline bool poison_slab_object(struct kmem_cache *cache, void *object,
+ unsigned long ip, bool init)
{
void *tagged_object;
@@ -208,16 +219,12 @@ static inline bool ____kasan_slab_free(struct kmem_cache *cache, void *object,
tagged_object = object;
object = kasan_reset_tag(object);
- if (is_kfence_address(object))
- return false;
-
- if (unlikely(nearest_obj(cache, virt_to_slab(object), object) !=
- object)) {
+ if (unlikely(nearest_obj(cache, virt_to_slab(object), object) != object)) {
kasan_report_invalid_free(tagged_object, ip, KASAN_REPORT_INVALID_FREE);
return true;
}
- /* RCU slabs could be legally used after free within the RCU period */
+ /* RCU slabs could be legally used after free within the RCU period. */
if (unlikely(cache->flags & SLAB_TYPESAFE_BY_RCU))
return false;
@@ -229,22 +236,44 @@ static inline bool ____kasan_slab_free(struct kmem_cache *cache, void *object,
kasan_poison(object, round_up(cache->object_size, KASAN_GRANULE_SIZE),
KASAN_SLAB_FREE, init);
- if ((IS_ENABLED(CONFIG_KASAN_GENERIC) && !quarantine))
- return false;
-
if (kasan_stack_collection_enabled())
kasan_save_free_info(cache, tagged_object);
- return kasan_quarantine_put(cache, object);
+ return false;
}
bool __kasan_slab_free(struct kmem_cache *cache, void *object,
unsigned long ip, bool init)
{
- return ____kasan_slab_free(cache, object, ip, true, init);
+ if (is_kfence_address(object))
+ return false;
+
+ /*
+ * If the object is buggy, do not let slab put the object onto the
+ * freelist. The object will thus never be allocated again and its
+ * metadata will never get released.
+ */
+ if (poison_slab_object(cache, object, ip, init))
+ return true;
+
+ /*
+ * If the object is put into quarantine, do not let slab put the object
+ * onto the freelist for now. The object's metadata is kept until the
+ * object gets evicted from quarantine.
+ */
+ if (kasan_quarantine_put(cache, object))
+ return true;
+
+ /*
+ * Note: Keep per-object metadata to allow KASAN print stack traces for
+ * use-after-free-before-realloc bugs.
+ */
+
+ /* Let slab put the object onto the freelist. */
+ return false;
}
-static inline bool ____kasan_kfree_large(void *ptr, unsigned long ip)
+static inline bool check_page_allocation(void *ptr, unsigned long ip)
{
if (!kasan_arch_is_ready())
return false;
@@ -259,40 +288,28 @@ static inline bool ____kasan_kfree_large(void *ptr, unsigned long ip)
return true;
}
- /*
- * The object will be poisoned by kasan_poison_pages() or
- * kasan_slab_free_mempool().
- */
-
return false;
}
void __kasan_kfree_large(void *ptr, unsigned long ip)
{
- ____kasan_kfree_large(ptr, ip);
+ check_page_allocation(ptr, ip);
+
+ /* The object will be poisoned by kasan_poison_pages(). */
}
-void __kasan_slab_free_mempool(void *ptr, unsigned long ip)
+static inline void unpoison_slab_object(struct kmem_cache *cache, void *object,
+ gfp_t flags, bool init)
{
- struct folio *folio;
-
- folio = virt_to_folio(ptr);
-
/*
- * Even though this function is only called for kmem_cache_alloc and
- * kmalloc backed mempool allocations, those allocations can still be
- * !PageSlab() when the size provided to kmalloc is larger than
- * KMALLOC_MAX_SIZE, and kmalloc falls back onto page_alloc.
+ * Unpoison the whole object. For kmalloc() allocations,
+ * poison_kmalloc_redzone() will do precise poisoning.
*/
- if (unlikely(!folio_test_slab(folio))) {
- if (____kasan_kfree_large(ptr, ip))
- return;
- kasan_poison(ptr, folio_size(folio), KASAN_PAGE_FREE, false);
- } else {
- struct slab *slab = folio_slab(folio);
+ kasan_unpoison(object, cache->object_size, init);
- ____kasan_slab_free(slab->slab_cache, ptr, ip, false, false);
- }
+ /* Save alloc info (if possible) for non-kmalloc() allocations. */
+ if (kasan_stack_collection_enabled() && !is_kmalloc_cache(cache))
+ kasan_save_alloc_info(cache, object, flags);
}
void * __must_check __kasan_slab_alloc(struct kmem_cache *cache,
@@ -317,39 +334,18 @@ void * __must_check __kasan_slab_alloc(struct kmem_cache *cache,
tag = assign_tag(cache, object, false);
tagged_object = set_tag(object, tag);
- /*
- * Unpoison the whole object.
- * For kmalloc() allocations, kasan_kmalloc() will do precise poisoning.
- */
- kasan_unpoison(tagged_object, cache->object_size, init);
-
- /* Save alloc info (if possible) for non-kmalloc() allocations. */
- if (kasan_stack_collection_enabled() && !is_kmalloc_cache(cache))
- kasan_save_alloc_info(cache, tagged_object, flags);
+ /* Unpoison the object and save alloc info for non-kmalloc() allocations. */
+ unpoison_slab_object(cache, tagged_object, flags, init);
return tagged_object;
}
-static inline void *____kasan_kmalloc(struct kmem_cache *cache,
+static inline void poison_kmalloc_redzone(struct kmem_cache *cache,
const void *object, size_t size, gfp_t flags)
{
unsigned long redzone_start;
unsigned long redzone_end;
- if (gfpflags_allow_blocking(flags))
- kasan_quarantine_reduce();
-
- if (unlikely(object == NULL))
- return NULL;
-
- if (is_kfence_address(kasan_reset_tag(object)))
- return (void *)object;
-
- /*
- * The object has already been unpoisoned by kasan_slab_alloc() for
- * kmalloc() or by kasan_krealloc() for krealloc().
- */
-
/*
* The redzone has byte-level precision for the generic mode.
* Partially poison the last object granule to cover the unaligned
@@ -373,34 +369,34 @@ static inline void *____kasan_kmalloc(struct kmem_cache *cache,
if (kasan_stack_collection_enabled() && is_kmalloc_cache(cache))
kasan_save_alloc_info(cache, (void *)object, flags);
- /* Keep the tag that was set by kasan_slab_alloc(). */
- return (void *)object;
}
void * __must_check __kasan_kmalloc(struct kmem_cache *cache, const void *object,
size_t size, gfp_t flags)
{
- return ____kasan_kmalloc(cache, object, size, flags);
+ if (gfpflags_allow_blocking(flags))
+ kasan_quarantine_reduce();
+
+ if (unlikely(object == NULL))
+ return NULL;
+
+ if (is_kfence_address(object))
+ return (void *)object;
+
+ /* The object has already been unpoisoned by kasan_slab_alloc(). */
+ poison_kmalloc_redzone(cache, object, size, flags);
+
+ /* Keep the tag that was set by kasan_slab_alloc(). */
+ return (void *)object;
}
EXPORT_SYMBOL(__kasan_kmalloc);
-void * __must_check __kasan_kmalloc_large(const void *ptr, size_t size,
+static inline void poison_kmalloc_large_redzone(const void *ptr, size_t size,
gfp_t flags)
{
unsigned long redzone_start;
unsigned long redzone_end;
- if (gfpflags_allow_blocking(flags))
- kasan_quarantine_reduce();
-
- if (unlikely(ptr == NULL))
- return NULL;
-
- /*
- * The object has already been unpoisoned by kasan_unpoison_pages() for
- * alloc_pages() or by kasan_krealloc() for krealloc().
- */
-
/*
* The redzone has byte-level precision for the generic mode.
* Partially poison the last object granule to cover the unaligned
@@ -410,12 +406,25 @@ void * __must_check __kasan_kmalloc_large(const void *ptr, size_t size,
kasan_poison_last_granule(ptr, size);
/* Poison the aligned part of the redzone. */
- redzone_start = round_up((unsigned long)(ptr + size),
- KASAN_GRANULE_SIZE);
+ redzone_start = round_up((unsigned long)(ptr + size), KASAN_GRANULE_SIZE);
redzone_end = (unsigned long)ptr + page_size(virt_to_page(ptr));
kasan_poison((void *)redzone_start, redzone_end - redzone_start,
KASAN_PAGE_REDZONE, false);
+}
+
+void * __must_check __kasan_kmalloc_large(const void *ptr, size_t size,
+ gfp_t flags)
+{
+ if (gfpflags_allow_blocking(flags))
+ kasan_quarantine_reduce();
+
+ if (unlikely(ptr == NULL))
+ return NULL;
+ /* The object has already been unpoisoned by kasan_unpoison_pages(). */
+ poison_kmalloc_large_redzone(ptr, size, flags);
+
+ /* Keep the tag that was set by alloc_pages(). */
return (void *)ptr;
}
@@ -423,9 +432,15 @@ void * __must_check __kasan_krealloc(const void *object, size_t size, gfp_t flag
{
struct slab *slab;
+ if (gfpflags_allow_blocking(flags))
+ kasan_quarantine_reduce();
+
if (unlikely(object == ZERO_SIZE_PTR))
return (void *)object;
+ if (is_kfence_address(object))
+ return (void *)object;
+
/*
* Unpoison the object's data.
* Part of it might already have been unpoisoned, but it's unknown
@@ -437,9 +452,91 @@ void * __must_check __kasan_krealloc(const void *object, size_t size, gfp_t flag
/* Piggy-back on kmalloc() instrumentation to poison the redzone. */
if (unlikely(!slab))
- return __kasan_kmalloc_large(object, size, flags);
+ poison_kmalloc_large_redzone(object, size, flags);
else
- return ____kasan_kmalloc(slab->slab_cache, object, size, flags);
+ poison_kmalloc_redzone(slab->slab_cache, object, size, flags);
+
+ return (void *)object;
+}
+
+bool __kasan_mempool_poison_pages(struct page *page, unsigned int order,
+ unsigned long ip)
+{
+ unsigned long *ptr;
+
+ if (unlikely(PageHighMem(page)))
+ return true;
+
+ /* Bail out if allocation was excluded due to sampling. */
+ if (!IS_ENABLED(CONFIG_KASAN_GENERIC) &&
+ page_kasan_tag(page) == KASAN_TAG_KERNEL)
+ return true;
+
+ ptr = page_address(page);
+
+ if (check_page_allocation(ptr, ip))
+ return false;
+
+ kasan_poison(ptr, PAGE_SIZE << order, KASAN_PAGE_FREE, false);
+
+ return true;
+}
+
+void __kasan_mempool_unpoison_pages(struct page *page, unsigned int order,
+ unsigned long ip)
+{
+ __kasan_unpoison_pages(page, order, false);
+}
+
+bool __kasan_mempool_poison_object(void *ptr, unsigned long ip)
+{
+ struct folio *folio = virt_to_folio(ptr);
+ struct slab *slab;
+
+ /*
+ * This function can be called for large kmalloc allocation that get
+ * their memory from page_alloc. Thus, the folio might not be a slab.
+ */
+ if (unlikely(!folio_test_slab(folio))) {
+ if (check_page_allocation(ptr, ip))
+ return false;
+ kasan_poison(ptr, folio_size(folio), KASAN_PAGE_FREE, false);
+ return true;
+ }
+
+ if (is_kfence_address(ptr))
+ return false;
+
+ slab = folio_slab(folio);
+ return !poison_slab_object(slab->slab_cache, ptr, ip, false);
+}
+
+void __kasan_mempool_unpoison_object(void *ptr, size_t size, unsigned long ip)
+{
+ struct slab *slab;
+ gfp_t flags = 0; /* Might be executing under a lock. */
+
+ slab = virt_to_slab(ptr);
+
+ /*
+ * This function can be called for large kmalloc allocation that get
+ * their memory from page_alloc.
+ */
+ if (unlikely(!slab)) {
+ kasan_unpoison(ptr, size, false);
+ poison_kmalloc_large_redzone(ptr, size, flags);
+ return;
+ }
+
+ if (is_kfence_address(ptr))
+ return;
+
+ /* Unpoison the object and save alloc info for non-kmalloc() allocations. */
+ unpoison_slab_object(slab->slab_cache, ptr, size, flags);
+
+ /* Poison the redzone and save alloc info for kmalloc() allocations. */
+ if (is_kmalloc_cache(slab->slab_cache))
+ poison_kmalloc_redzone(slab->slab_cache, ptr, size, flags);
}
bool __kasan_check_byte(const void *address, unsigned long ip)
diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c
index 4d837ab83f08..1900f8576034 100644
--- a/mm/kasan/generic.c
+++ b/mm/kasan/generic.c
@@ -25,6 +25,8 @@
#include <linux/sched.h>
#include <linux/sched/task_stack.h>
#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/stackdepot.h>
#include <linux/stacktrace.h>
#include <linux/string.h>
#include <linux/types.h>
@@ -361,6 +363,8 @@ void kasan_cache_create(struct kmem_cache *cache, unsigned int *size,
{
unsigned int ok_size;
unsigned int optimal_size;
+ unsigned int rem_free_meta_size;
+ unsigned int orig_alloc_meta_offset;
if (!kasan_requires_meta())
return;
@@ -378,49 +382,77 @@ void kasan_cache_create(struct kmem_cache *cache, unsigned int *size,
ok_size = *size;
- /* Add alloc meta into redzone. */
+ /* Add alloc meta into the redzone. */
cache->kasan_info.alloc_meta_offset = *size;
*size += sizeof(struct kasan_alloc_meta);
- /*
- * If alloc meta doesn't fit, don't add it.
- * This can only happen with SLAB, as it has KMALLOC_MAX_SIZE equal
- * to KMALLOC_MAX_CACHE_SIZE and doesn't fall back to page_alloc for
- * larger sizes.
- */
+ /* If alloc meta doesn't fit, don't add it. */
if (*size > KMALLOC_MAX_SIZE) {
cache->kasan_info.alloc_meta_offset = 0;
*size = ok_size;
/* Continue, since free meta might still fit. */
}
+ ok_size = *size;
+ orig_alloc_meta_offset = cache->kasan_info.alloc_meta_offset;
+
/*
- * Add free meta into redzone when it's not possible to store
+ * Store free meta in the redzone when it's not possible to store
* it in the object. This is the case when:
* 1. Object is SLAB_TYPESAFE_BY_RCU, which means that it can
* be touched after it was freed, or
* 2. Object has a constructor, which means it's expected to
- * retain its content until the next allocation, or
- * 3. Object is too small.
- * Otherwise cache->kasan_info.free_meta_offset = 0 is implied.
+ * retain its content until the next allocation.
*/
- if ((cache->flags & SLAB_TYPESAFE_BY_RCU) || cache->ctor ||
- cache->object_size < sizeof(struct kasan_free_meta)) {
- ok_size = *size;
-
+ if ((cache->flags & SLAB_TYPESAFE_BY_RCU) || cache->ctor) {
cache->kasan_info.free_meta_offset = *size;
*size += sizeof(struct kasan_free_meta);
+ goto free_meta_added;
+ }
- /* If free meta doesn't fit, don't add it. */
- if (*size > KMALLOC_MAX_SIZE) {
- cache->kasan_info.free_meta_offset = KASAN_NO_FREE_META;
- *size = ok_size;
- }
+ /*
+ * Otherwise, if the object is large enough to contain free meta,
+ * store it within the object.
+ */
+ if (sizeof(struct kasan_free_meta) <= cache->object_size) {
+ /* cache->kasan_info.free_meta_offset = 0 is implied. */
+ goto free_meta_added;
+ }
+
+ /*
+ * For smaller objects, store the beginning of free meta within the
+ * object and the end in the redzone. And thus shift the location of
+ * alloc meta to free up space for free meta.
+ * This is only possible when slub_debug is disabled, as otherwise
+ * the end of free meta will overlap with slub_debug metadata.
+ */
+ if (!__slub_debug_enabled()) {
+ rem_free_meta_size = sizeof(struct kasan_free_meta) -
+ cache->object_size;
+ *size += rem_free_meta_size;
+ if (cache->kasan_info.alloc_meta_offset != 0)
+ cache->kasan_info.alloc_meta_offset += rem_free_meta_size;
+ goto free_meta_added;
+ }
+
+ /*
+ * If the object is small and slub_debug is enabled, store free meta
+ * in the redzone after alloc meta.
+ */
+ cache->kasan_info.free_meta_offset = *size;
+ *size += sizeof(struct kasan_free_meta);
+
+free_meta_added:
+ /* If free meta doesn't fit, don't add it. */
+ if (*size > KMALLOC_MAX_SIZE) {
+ cache->kasan_info.free_meta_offset = KASAN_NO_FREE_META;
+ cache->kasan_info.alloc_meta_offset = orig_alloc_meta_offset;
+ *size = ok_size;
}
/* Calculate size with optimal redzone. */
optimal_size = cache->object_size + optimal_redzone(cache->object_size);
- /* Limit it with KMALLOC_MAX_SIZE (relevant for SLAB only). */
+ /* Limit it with KMALLOC_MAX_SIZE. */
if (optimal_size > KMALLOC_MAX_SIZE)
optimal_size = KMALLOC_MAX_SIZE;
/* Use optimal size if the size with added metas is not large enough. */
@@ -450,8 +482,35 @@ void kasan_init_object_meta(struct kmem_cache *cache, const void *object)
struct kasan_alloc_meta *alloc_meta;
alloc_meta = kasan_get_alloc_meta(cache, object);
- if (alloc_meta)
+ if (alloc_meta) {
+ /* Zero out alloc meta to mark it as invalid. */
__memset(alloc_meta, 0, sizeof(*alloc_meta));
+ }
+
+ /*
+ * Explicitly marking free meta as invalid is not required: the shadow
+ * value for the first 8 bytes of a newly allocated object is not
+ * KASAN_SLAB_FREE_META.
+ */
+}
+
+static void release_alloc_meta(struct kasan_alloc_meta *meta)
+{
+ /* Zero out alloc meta to mark it as invalid. */
+ __memset(meta, 0, sizeof(*meta));
+}
+
+static void release_free_meta(const void *object, struct kasan_free_meta *meta)
+{
+ if (!kasan_arch_is_ready())
+ return;
+
+ /* Check if free meta is valid. */
+ if (*(u8 *)kasan_mem_to_shadow(object) != KASAN_SLAB_FREE_META)
+ return;
+
+ /* Mark free meta as invalid. */
+ *(u8 *)kasan_mem_to_shadow(object) = KASAN_SLAB_FREE;
}
size_t kasan_metadata_size(struct kmem_cache *cache, bool in_object)
@@ -472,7 +531,7 @@ size_t kasan_metadata_size(struct kmem_cache *cache, bool in_object)
sizeof(struct kasan_free_meta) : 0);
}
-static void __kasan_record_aux_stack(void *addr, bool can_alloc)
+static void __kasan_record_aux_stack(void *addr, depot_flags_t depot_flags)
{
struct slab *slab = kasan_addr_to_slab(addr);
struct kmem_cache *cache;
@@ -489,17 +548,17 @@ static void __kasan_record_aux_stack(void *addr, bool can_alloc)
return;
alloc_meta->aux_stack[1] = alloc_meta->aux_stack[0];
- alloc_meta->aux_stack[0] = kasan_save_stack(0, can_alloc);
+ alloc_meta->aux_stack[0] = kasan_save_stack(0, depot_flags);
}
void kasan_record_aux_stack(void *addr)
{
- return __kasan_record_aux_stack(addr, true);
+ return __kasan_record_aux_stack(addr, STACK_DEPOT_FLAG_CAN_ALLOC);
}
void kasan_record_aux_stack_noalloc(void *addr)
{
- return __kasan_record_aux_stack(addr, false);
+ return __kasan_record_aux_stack(addr, 0);
}
void kasan_save_alloc_info(struct kmem_cache *cache, void *object, gfp_t flags)
@@ -507,8 +566,13 @@ void kasan_save_alloc_info(struct kmem_cache *cache, void *object, gfp_t flags)
struct kasan_alloc_meta *alloc_meta;
alloc_meta = kasan_get_alloc_meta(cache, object);
- if (alloc_meta)
- kasan_set_track(&alloc_meta->alloc_track, flags);
+ if (!alloc_meta)
+ return;
+
+ /* Invalidate previous stack traces (might exist for krealloc or mempool). */
+ release_alloc_meta(alloc_meta);
+
+ kasan_save_track(&alloc_meta->alloc_track, flags);
}
void kasan_save_free_info(struct kmem_cache *cache, void *object)
@@ -519,7 +583,11 @@ void kasan_save_free_info(struct kmem_cache *cache, void *object)
if (!free_meta)
return;
- kasan_set_track(&free_meta->free_track, 0);
- /* The object was freed and has free track set. */
- *(u8 *)kasan_mem_to_shadow(object) = KASAN_SLAB_FREETRACK;
+ /* Invalidate previous stack trace (might exist for mempool). */
+ release_free_meta(object, free_meta);
+
+ kasan_save_track(&free_meta->free_track, 0);
+
+ /* Mark free meta as valid. */
+ *(u8 *)kasan_mem_to_shadow(object) = KASAN_SLAB_FREE_META;
}
diff --git a/mm/kasan/hw_tags.c b/mm/kasan/hw_tags.c
index 06141bbc1e51..2b994092a2d4 100644
--- a/mm/kasan/hw_tags.c
+++ b/mm/kasan/hw_tags.c
@@ -57,7 +57,12 @@ enum kasan_mode kasan_mode __ro_after_init;
EXPORT_SYMBOL_GPL(kasan_mode);
/* Whether to enable vmalloc tagging. */
+#ifdef CONFIG_KASAN_VMALLOC
DEFINE_STATIC_KEY_TRUE(kasan_flag_vmalloc);
+#else
+DEFINE_STATIC_KEY_FALSE(kasan_flag_vmalloc);
+#endif
+EXPORT_SYMBOL_GPL(kasan_flag_vmalloc);
#define PAGE_ALLOC_SAMPLE_DEFAULT 1
#define PAGE_ALLOC_SAMPLE_ORDER_DEFAULT 3
@@ -119,6 +124,9 @@ static int __init early_kasan_flag_vmalloc(char *arg)
if (!arg)
return -EINVAL;
+ if (!IS_ENABLED(CONFIG_KASAN_VMALLOC))
+ return 0;
+
if (!strcmp(arg, "off"))
kasan_arg_vmalloc = KASAN_ARG_VMALLOC_OFF;
else if (!strcmp(arg, "on"))
diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
index 8b06bab5c406..fb2b9ac0659a 100644
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h
@@ -48,6 +48,7 @@ DECLARE_PER_CPU(long, kasan_page_alloc_skip);
static inline bool kasan_vmalloc_enabled(void)
{
+ /* Static branch is never enabled with CONFIG_KASAN_VMALLOC disabled. */
return static_branch_likely(&kasan_flag_vmalloc);
}
@@ -81,6 +82,11 @@ static inline bool kasan_sample_page_alloc(unsigned int order)
#else /* CONFIG_KASAN_HW_TAGS */
+static inline bool kasan_vmalloc_enabled(void)
+{
+ return IS_ENABLED(CONFIG_KASAN_VMALLOC);
+}
+
static inline bool kasan_async_fault_possible(void)
{
return false;
@@ -100,21 +106,21 @@ static inline bool kasan_sample_page_alloc(unsigned int order)
#ifdef CONFIG_KASAN_GENERIC
-/* Generic KASAN uses per-object metadata to store stack traces. */
+/*
+ * Generic KASAN uses per-object metadata to store alloc and free stack traces
+ * and the quarantine link.
+ */
static inline bool kasan_requires_meta(void)
{
- /*
- * Technically, Generic KASAN always collects stack traces right now.
- * However, let's use kasan_stack_collection_enabled() in case the
- * kasan.stacktrace command-line argument is changed to affect
- * Generic KASAN.
- */
- return kasan_stack_collection_enabled();
+ return true;
}
#else /* CONFIG_KASAN_GENERIC */
-/* Tag-based KASAN modes do not use per-object metadata. */
+/*
+ * Tag-based KASAN modes do not use per-object metadata: they use the stack
+ * ring to store alloc and free stack traces and do not use qurantine.
+ */
static inline bool kasan_requires_meta(void)
{
return false;
@@ -149,7 +155,7 @@ static inline bool kasan_requires_meta(void)
#ifdef CONFIG_KASAN_GENERIC
-#define KASAN_SLAB_FREETRACK 0xFA /* freed slab object with free track */
+#define KASAN_SLAB_FREE_META 0xFA /* freed slab object with free meta */
#define KASAN_GLOBAL_REDZONE 0xF9 /* redzone for global variable */
/* Stack redzone shadow values. Compiler ABI, do not change. */
@@ -187,6 +193,10 @@ static inline bool kasan_requires_meta(void)
struct kasan_track {
u32 pid;
depot_stack_handle_t stack;
+#ifdef CONFIG_KASAN_EXTRA_INFO
+ u64 cpu:20;
+ u64 timestamp:44;
+#endif /* CONFIG_KASAN_EXTRA_INFO */
};
enum kasan_report_type {
@@ -242,6 +252,15 @@ struct kasan_global {
#ifdef CONFIG_KASAN_GENERIC
+/*
+ * Alloc meta contains the allocation-related information about a slab object.
+ * Alloc meta is saved when an object is allocated and is kept until either the
+ * object returns to the slab freelist (leaves quarantine for quarantined
+ * objects or gets freed for the non-quarantined ones) or reallocated via
+ * krealloc or through a mempool.
+ * Alloc meta is stored inside of the object's redzone.
+ * Alloc meta is considered valid whenever it contains non-zero data.
+ */
struct kasan_alloc_meta {
struct kasan_track alloc_track;
/* Free track is stored in kasan_free_meta. */
@@ -260,8 +279,12 @@ struct qlist_node {
#define KASAN_NO_FREE_META INT_MAX
/*
- * Free meta is only used by Generic mode while the object is in quarantine.
- * After that, slab allocator stores the freelist pointer in the object.
+ * Free meta contains the freeing-related information about a slab object.
+ * Free meta is only kept for quarantined objects and for mempool objects until
+ * the object gets allocated again.
+ * Free meta is stored within the object's memory.
+ * Free meta is considered valid whenever the value of the shadow byte that
+ * corresponds to the first 8 bytes of the object is KASAN_SLAB_FREE_META.
*/
struct kasan_free_meta {
struct qlist_node quarantine_link;
@@ -275,8 +298,7 @@ struct kasan_free_meta {
struct kasan_stack_ring_entry {
void *ptr;
size_t size;
- u32 pid;
- depot_stack_handle_t stack;
+ struct kasan_track track;
bool is_free;
};
@@ -291,6 +313,12 @@ struct kasan_stack_ring {
#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
+static __always_inline bool addr_in_shadow(const void *addr)
+{
+ return addr >= (void *)KASAN_SHADOW_START &&
+ addr < (void *)KASAN_SHADOW_END;
+}
+
#ifndef kasan_shadow_to_mem
static inline const void *kasan_shadow_to_mem(const void *shadow_addr)
{
@@ -357,24 +385,22 @@ void kasan_report_invalid_free(void *object, unsigned long ip, enum kasan_report
struct slab *kasan_addr_to_slab(const void *addr);
#ifdef CONFIG_KASAN_GENERIC
-void kasan_init_cache_meta(struct kmem_cache *cache, unsigned int *size);
-void kasan_init_object_meta(struct kmem_cache *cache, const void *object);
struct kasan_alloc_meta *kasan_get_alloc_meta(struct kmem_cache *cache,
const void *object);
struct kasan_free_meta *kasan_get_free_meta(struct kmem_cache *cache,
const void *object);
+void kasan_init_object_meta(struct kmem_cache *cache, const void *object);
#else
-static inline void kasan_init_cache_meta(struct kmem_cache *cache, unsigned int *size) { }
static inline void kasan_init_object_meta(struct kmem_cache *cache, const void *object) { }
#endif
-depot_stack_handle_t kasan_save_stack(gfp_t flags, bool can_alloc);
-void kasan_set_track(struct kasan_track *track, gfp_t flags);
+depot_stack_handle_t kasan_save_stack(gfp_t flags, depot_flags_t depot_flags);
+void kasan_set_track(struct kasan_track *track, depot_stack_handle_t stack);
+void kasan_save_track(struct kasan_track *track, gfp_t flags);
void kasan_save_alloc_info(struct kmem_cache *cache, void *object, gfp_t flags);
void kasan_save_free_info(struct kmem_cache *cache, void *object);
-#if defined(CONFIG_KASAN_GENERIC) && \
- (defined(CONFIG_SLAB) || defined(CONFIG_SLUB))
+#ifdef CONFIG_KASAN_GENERIC
bool kasan_quarantine_put(struct kmem_cache *cache, void *object);
void kasan_quarantine_reduce(void);
void kasan_quarantine_remove_cache(struct kmem_cache *cache);
@@ -444,35 +470,23 @@ static inline u8 kasan_random_tag(void) { return 0; }
static inline void kasan_poison(const void *addr, size_t size, u8 value, bool init)
{
- addr = kasan_reset_tag(addr);
-
- /* Skip KFENCE memory if called explicitly outside of sl*b. */
- if (is_kfence_address(addr))
- return;
-
if (WARN_ON((unsigned long)addr & KASAN_GRANULE_MASK))
return;
if (WARN_ON(size & KASAN_GRANULE_MASK))
return;
- hw_set_mem_tag_range((void *)addr, size, value, init);
+ hw_set_mem_tag_range(kasan_reset_tag(addr), size, value, init);
}
static inline void kasan_unpoison(const void *addr, size_t size, bool init)
{
u8 tag = get_tag(addr);
- addr = kasan_reset_tag(addr);
-
- /* Skip KFENCE memory if called explicitly outside of sl*b. */
- if (is_kfence_address(addr))
- return;
-
if (WARN_ON((unsigned long)addr & KASAN_GRANULE_MASK))
return;
size = round_up(size, KASAN_GRANULE_SIZE);
- hw_set_mem_tag_range((void *)addr, size, tag, init);
+ hw_set_mem_tag_range(kasan_reset_tag(addr), size, tag, init);
}
static inline bool kasan_byte_accessible(const void *addr)
@@ -491,8 +505,6 @@ static inline bool kasan_byte_accessible(const void *addr)
* @size - range size, must be aligned to KASAN_GRANULE_SIZE
* @value - value that's written to metadata for the range
* @init - whether to initialize the memory range (only for hardware tag-based)
- *
- * The size gets aligned to KASAN_GRANULE_SIZE before marking the range.
*/
void kasan_poison(const void *addr, size_t size, u8 value, bool init);
diff --git a/mm/kasan/kasan_test.c b/mm/kasan/kasan_test.c
index 34515a106ca5..971cfff4ca0b 100644
--- a/mm/kasan/kasan_test.c
+++ b/mm/kasan/kasan_test.c
@@ -13,6 +13,7 @@
#include <linux/io.h>
#include <linux/kasan.h>
#include <linux/kernel.h>
+#include <linux/mempool.h>
#include <linux/mm.h>
#include <linux/mman.h>
#include <linux/module.h>
@@ -213,17 +214,32 @@ static void kmalloc_node_oob_right(struct kunit *test)
}
/*
- * 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.
+ * Check that KASAN detects an out-of-bounds access for a big object allocated
+ * via kmalloc(). But not as big as to trigger the page_alloc fallback.
*/
-static void kmalloc_pagealloc_oob_right(struct kunit *test)
+static void kmalloc_big_oob_right(struct kunit *test)
{
char *ptr;
- size_t size = KMALLOC_MAX_CACHE_SIZE + 10;
+ size_t size = KMALLOC_MAX_CACHE_SIZE - 256;
+
+ ptr = kmalloc(size, GFP_KERNEL);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
+
+ OPTIMIZER_HIDE_VAR(ptr);
+ KUNIT_EXPECT_KASAN_FAIL(test, ptr[size] = 0);
+ kfree(ptr);
+}
- KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_SLUB);
+/*
+ * The kmalloc_large_* tests below use kmalloc() to allocate a memory chunk
+ * that does not fit into the largest slab cache and therefore is allocated via
+ * the page_alloc fallback.
+ */
+
+static void kmalloc_large_oob_right(struct kunit *test)
+{
+ char *ptr;
+ size_t size = KMALLOC_MAX_CACHE_SIZE + 10;
ptr = kmalloc(size, GFP_KERNEL);
KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
@@ -234,13 +250,11 @@ static void kmalloc_pagealloc_oob_right(struct kunit *test)
kfree(ptr);
}
-static void kmalloc_pagealloc_uaf(struct kunit *test)
+static void kmalloc_large_uaf(struct kunit *test)
{
char *ptr;
size_t size = KMALLOC_MAX_CACHE_SIZE + 10;
- KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_SLUB);
-
ptr = kmalloc(size, GFP_KERNEL);
KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
kfree(ptr);
@@ -248,20 +262,18 @@ static void kmalloc_pagealloc_uaf(struct kunit *test)
KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[0]);
}
-static void kmalloc_pagealloc_invalid_free(struct kunit *test)
+static void kmalloc_large_invalid_free(struct kunit *test)
{
char *ptr;
size_t size = KMALLOC_MAX_CACHE_SIZE + 10;
- KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_SLUB);
-
ptr = kmalloc(size, GFP_KERNEL);
KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
KUNIT_EXPECT_KASAN_FAIL(test, kfree(ptr + 1));
}
-static void pagealloc_oob_right(struct kunit *test)
+static void page_alloc_oob_right(struct kunit *test)
{
char *ptr;
struct page *pages;
@@ -283,7 +295,7 @@ static void pagealloc_oob_right(struct kunit *test)
free_pages((unsigned long)ptr, order);
}
-static void pagealloc_uaf(struct kunit *test)
+static void page_alloc_uaf(struct kunit *test)
{
char *ptr;
struct page *pages;
@@ -297,23 +309,6 @@ static void pagealloc_uaf(struct kunit *test)
KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[0]);
}
-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
- * and does not trigger the page allocator fallback in SLUB.
- */
- ptr = kmalloc(size, GFP_KERNEL);
- KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
-
- OPTIMIZER_HIDE_VAR(ptr);
- KUNIT_EXPECT_KASAN_FAIL(test, ptr[size] = 0);
- kfree(ptr);
-}
-
static void krealloc_more_oob_helper(struct kunit *test,
size_t size1, size_t size2)
{
@@ -403,20 +398,14 @@ static void krealloc_less_oob(struct kunit *test)
krealloc_less_oob_helper(test, 235, 201);
}
-static void krealloc_pagealloc_more_oob(struct kunit *test)
+static void krealloc_large_more_oob(struct kunit *test)
{
- /* page_alloc fallback in only implemented for SLUB. */
- KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_SLUB);
-
krealloc_more_oob_helper(test, KMALLOC_MAX_CACHE_SIZE + 201,
KMALLOC_MAX_CACHE_SIZE + 235);
}
-static void krealloc_pagealloc_less_oob(struct kunit *test)
+static void krealloc_large_less_oob(struct kunit *test)
{
- /* page_alloc fallback in only implemented for SLUB. */
- KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_SLUB);
-
krealloc_less_oob_helper(test, KMALLOC_MAX_CACHE_SIZE + 235,
KMALLOC_MAX_CACHE_SIZE + 201);
}
@@ -708,6 +697,126 @@ static void kmalloc_uaf3(struct kunit *test)
KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr1)[8]);
}
+static void kmalloc_double_kzfree(struct kunit *test)
+{
+ char *ptr;
+ size_t size = 16;
+
+ ptr = kmalloc(size, GFP_KERNEL);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
+
+ kfree_sensitive(ptr);
+ KUNIT_EXPECT_KASAN_FAIL(test, kfree_sensitive(ptr));
+}
+
+/* Check that ksize() does NOT unpoison whole object. */
+static void ksize_unpoisons_memory(struct kunit *test)
+{
+ char *ptr;
+ size_t size = 128 - KASAN_GRANULE_SIZE - 5;
+ size_t real_size;
+
+ ptr = kmalloc(size, GFP_KERNEL);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
+
+ real_size = ksize(ptr);
+ KUNIT_EXPECT_GT(test, real_size, size);
+
+ OPTIMIZER_HIDE_VAR(ptr);
+
+ /* These accesses shouldn't trigger a KASAN report. */
+ ptr[0] = 'x';
+ ptr[size - 1] = 'x';
+
+ /* These must trigger a KASAN report. */
+ if (IS_ENABLED(CONFIG_KASAN_GENERIC))
+ KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[size]);
+ KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[size + 5]);
+ KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[real_size - 1]);
+
+ 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);
+
+ OPTIMIZER_HIDE_VAR(ptr);
+ KUNIT_EXPECT_KASAN_FAIL(test, ksize(ptr));
+ KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[0]);
+ KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[size]);
+}
+
+/*
+ * The two tests below check that Generic KASAN prints auxiliary stack traces
+ * for RCU callbacks and workqueues. The reports need to be inspected manually.
+ *
+ * These tests are still enabled for other KASAN modes to make sure that all
+ * modes report bad accesses in tested scenarios.
+ */
+
+static struct kasan_rcu_info {
+ int i;
+ struct rcu_head rcu;
+} *global_rcu_ptr;
+
+static void rcu_uaf_reclaim(struct rcu_head *rp)
+{
+ struct kasan_rcu_info *fp =
+ container_of(rp, struct kasan_rcu_info, rcu);
+
+ kfree(fp);
+ ((volatile struct kasan_rcu_info *)fp)->i;
+}
+
+static void rcu_uaf(struct kunit *test)
+{
+ struct kasan_rcu_info *ptr;
+
+ ptr = kmalloc(sizeof(struct kasan_rcu_info), GFP_KERNEL);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
+
+ global_rcu_ptr = rcu_dereference_protected(
+ (struct kasan_rcu_info __rcu *)ptr, NULL);
+
+ KUNIT_EXPECT_KASAN_FAIL(test,
+ call_rcu(&global_rcu_ptr->rcu, rcu_uaf_reclaim);
+ rcu_barrier());
+}
+
+static void workqueue_uaf_work(struct work_struct *work)
+{
+ kfree(work);
+}
+
+static void workqueue_uaf(struct kunit *test)
+{
+ struct workqueue_struct *workqueue;
+ struct work_struct *work;
+
+ workqueue = create_workqueue("kasan_workqueue_test");
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, workqueue);
+
+ work = kmalloc(sizeof(struct work_struct), GFP_KERNEL);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, work);
+
+ INIT_WORK(work, workqueue_uaf_work);
+ queue_work(workqueue, work);
+ destroy_workqueue(workqueue);
+
+ KUNIT_EXPECT_KASAN_FAIL(test,
+ ((volatile struct work_struct *)work)->data);
+}
+
static void kfree_via_page(struct kunit *test)
{
char *ptr;
@@ -758,6 +867,69 @@ static void kmem_cache_oob(struct kunit *test)
kmem_cache_destroy(cache);
}
+static void kmem_cache_double_free(struct kunit *test)
+{
+ char *p;
+ size_t size = 200;
+ 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__);
+ kmem_cache_destroy(cache);
+ return;
+ }
+
+ kmem_cache_free(cache, p);
+ KUNIT_EXPECT_KASAN_FAIL(test, kmem_cache_free(cache, p));
+ kmem_cache_destroy(cache);
+}
+
+static void kmem_cache_invalid_free(struct kunit *test)
+{
+ char *p;
+ size_t size = 200;
+ struct kmem_cache *cache;
+
+ cache = kmem_cache_create("test_cache", size, 0, SLAB_TYPESAFE_BY_RCU,
+ 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__);
+ kmem_cache_destroy(cache);
+ return;
+ }
+
+ /* Trigger invalid free, the object doesn't get freed. */
+ KUNIT_EXPECT_KASAN_FAIL(test, kmem_cache_free(cache, p + 1));
+
+ /*
+ * Properly free the object to prevent the "Objects remaining in
+ * test_cache on __kmem_cache_shutdown" BUG failure.
+ */
+ kmem_cache_free(cache, p);
+
+ kmem_cache_destroy(cache);
+}
+
+static void empty_cache_ctor(void *object) { }
+
+static void kmem_cache_double_destroy(struct kunit *test)
+{
+ struct kmem_cache *cache;
+
+ /* Provide a constructor to prevent cache merging. */
+ cache = kmem_cache_create("test_cache", 200, 0, 0, empty_cache_ctor);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cache);
+ kmem_cache_destroy(cache);
+ KUNIT_EXPECT_KASAN_FAIL(test, kmem_cache_destroy(cache));
+}
+
static void kmem_cache_accounted(struct kunit *test)
{
int i;
@@ -810,6 +982,303 @@ static void kmem_cache_bulk(struct kunit *test)
kmem_cache_destroy(cache);
}
+static void *mempool_prepare_kmalloc(struct kunit *test, mempool_t *pool, size_t size)
+{
+ int pool_size = 4;
+ int ret;
+ void *elem;
+
+ memset(pool, 0, sizeof(*pool));
+ ret = mempool_init_kmalloc_pool(pool, pool_size, size);
+ KUNIT_ASSERT_EQ(test, ret, 0);
+
+ /*
+ * Allocate one element to prevent mempool from freeing elements to the
+ * underlying allocator and instead make it add them to the element
+ * list when the tests trigger double-free and invalid-free bugs.
+ * This allows testing KASAN annotations in add_element().
+ */
+ elem = mempool_alloc_preallocated(pool);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, elem);
+
+ return elem;
+}
+
+static struct kmem_cache *mempool_prepare_slab(struct kunit *test, mempool_t *pool, size_t size)
+{
+ struct kmem_cache *cache;
+ int pool_size = 4;
+ int ret;
+
+ cache = kmem_cache_create("test_cache", size, 0, 0, NULL);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cache);
+
+ memset(pool, 0, sizeof(*pool));
+ ret = mempool_init_slab_pool(pool, pool_size, cache);
+ KUNIT_ASSERT_EQ(test, ret, 0);
+
+ /*
+ * Do not allocate one preallocated element, as we skip the double-free
+ * and invalid-free tests for slab mempool for simplicity.
+ */
+
+ return cache;
+}
+
+static void *mempool_prepare_page(struct kunit *test, mempool_t *pool, int order)
+{
+ int pool_size = 4;
+ int ret;
+ void *elem;
+
+ memset(pool, 0, sizeof(*pool));
+ ret = mempool_init_page_pool(pool, pool_size, order);
+ KUNIT_ASSERT_EQ(test, ret, 0);
+
+ elem = mempool_alloc_preallocated(pool);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, elem);
+
+ return elem;
+}
+
+static void mempool_oob_right_helper(struct kunit *test, mempool_t *pool, size_t size)
+{
+ char *elem;
+
+ elem = mempool_alloc_preallocated(pool);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, elem);
+
+ OPTIMIZER_HIDE_VAR(elem);
+
+ if (IS_ENABLED(CONFIG_KASAN_GENERIC))
+ KUNIT_EXPECT_KASAN_FAIL(test,
+ ((volatile char *)&elem[size])[0]);
+ else
+ KUNIT_EXPECT_KASAN_FAIL(test,
+ ((volatile char *)&elem[round_up(size, KASAN_GRANULE_SIZE)])[0]);
+
+ mempool_free(elem, pool);
+}
+
+static void mempool_kmalloc_oob_right(struct kunit *test)
+{
+ mempool_t pool;
+ size_t size = 128 - KASAN_GRANULE_SIZE - 5;
+ void *extra_elem;
+
+ extra_elem = mempool_prepare_kmalloc(test, &pool, size);
+
+ mempool_oob_right_helper(test, &pool, size);
+
+ mempool_free(extra_elem, &pool);
+ mempool_exit(&pool);
+}
+
+static void mempool_kmalloc_large_oob_right(struct kunit *test)
+{
+ mempool_t pool;
+ size_t size = KMALLOC_MAX_CACHE_SIZE + 1;
+ void *extra_elem;
+
+ extra_elem = mempool_prepare_kmalloc(test, &pool, size);
+
+ mempool_oob_right_helper(test, &pool, size);
+
+ mempool_free(extra_elem, &pool);
+ mempool_exit(&pool);
+}
+
+static void mempool_slab_oob_right(struct kunit *test)
+{
+ mempool_t pool;
+ size_t size = 123;
+ struct kmem_cache *cache;
+
+ cache = mempool_prepare_slab(test, &pool, size);
+
+ mempool_oob_right_helper(test, &pool, size);
+
+ mempool_exit(&pool);
+ kmem_cache_destroy(cache);
+}
+
+/*
+ * Skip the out-of-bounds test for page mempool. With Generic KASAN, page
+ * allocations have no redzones, and thus the out-of-bounds detection is not
+ * guaranteed; see https://bugzilla.kernel.org/show_bug.cgi?id=210503. With
+ * the tag-based KASAN modes, the neighboring allocation might have the same
+ * tag; see https://bugzilla.kernel.org/show_bug.cgi?id=203505.
+ */
+
+static void mempool_uaf_helper(struct kunit *test, mempool_t *pool, bool page)
+{
+ char *elem, *ptr;
+
+ elem = mempool_alloc_preallocated(pool);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, elem);
+
+ mempool_free(elem, pool);
+
+ ptr = page ? page_address((struct page *)elem) : elem;
+ KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[0]);
+}
+
+static void mempool_kmalloc_uaf(struct kunit *test)
+{
+ mempool_t pool;
+ size_t size = 128;
+ void *extra_elem;
+
+ extra_elem = mempool_prepare_kmalloc(test, &pool, size);
+
+ mempool_uaf_helper(test, &pool, false);
+
+ mempool_free(extra_elem, &pool);
+ mempool_exit(&pool);
+}
+
+static void mempool_kmalloc_large_uaf(struct kunit *test)
+{
+ mempool_t pool;
+ size_t size = KMALLOC_MAX_CACHE_SIZE + 1;
+ void *extra_elem;
+
+ extra_elem = mempool_prepare_kmalloc(test, &pool, size);
+
+ mempool_uaf_helper(test, &pool, false);
+
+ mempool_free(extra_elem, &pool);
+ mempool_exit(&pool);
+}
+
+static void mempool_slab_uaf(struct kunit *test)
+{
+ mempool_t pool;
+ size_t size = 123;
+ struct kmem_cache *cache;
+
+ cache = mempool_prepare_slab(test, &pool, size);
+
+ mempool_uaf_helper(test, &pool, false);
+
+ mempool_exit(&pool);
+ kmem_cache_destroy(cache);
+}
+
+static void mempool_page_alloc_uaf(struct kunit *test)
+{
+ mempool_t pool;
+ int order = 2;
+ void *extra_elem;
+
+ extra_elem = mempool_prepare_page(test, &pool, order);
+
+ mempool_uaf_helper(test, &pool, true);
+
+ mempool_free(extra_elem, &pool);
+ mempool_exit(&pool);
+}
+
+static void mempool_double_free_helper(struct kunit *test, mempool_t *pool)
+{
+ char *elem;
+
+ elem = mempool_alloc_preallocated(pool);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, elem);
+
+ mempool_free(elem, pool);
+
+ KUNIT_EXPECT_KASAN_FAIL(test, mempool_free(elem, pool));
+}
+
+static void mempool_kmalloc_double_free(struct kunit *test)
+{
+ mempool_t pool;
+ size_t size = 128;
+ char *extra_elem;
+
+ extra_elem = mempool_prepare_kmalloc(test, &pool, size);
+
+ mempool_double_free_helper(test, &pool);
+
+ mempool_free(extra_elem, &pool);
+ mempool_exit(&pool);
+}
+
+static void mempool_kmalloc_large_double_free(struct kunit *test)
+{
+ mempool_t pool;
+ size_t size = KMALLOC_MAX_CACHE_SIZE + 1;
+ char *extra_elem;
+
+ extra_elem = mempool_prepare_kmalloc(test, &pool, size);
+
+ mempool_double_free_helper(test, &pool);
+
+ mempool_free(extra_elem, &pool);
+ mempool_exit(&pool);
+}
+
+static void mempool_page_alloc_double_free(struct kunit *test)
+{
+ mempool_t pool;
+ int order = 2;
+ char *extra_elem;
+
+ extra_elem = mempool_prepare_page(test, &pool, order);
+
+ mempool_double_free_helper(test, &pool);
+
+ mempool_free(extra_elem, &pool);
+ mempool_exit(&pool);
+}
+
+static void mempool_kmalloc_invalid_free_helper(struct kunit *test, mempool_t *pool)
+{
+ char *elem;
+
+ elem = mempool_alloc_preallocated(pool);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, elem);
+
+ KUNIT_EXPECT_KASAN_FAIL(test, mempool_free(elem + 1, pool));
+
+ mempool_free(elem, pool);
+}
+
+static void mempool_kmalloc_invalid_free(struct kunit *test)
+{
+ mempool_t pool;
+ size_t size = 128;
+ char *extra_elem;
+
+ extra_elem = mempool_prepare_kmalloc(test, &pool, size);
+
+ mempool_kmalloc_invalid_free_helper(test, &pool);
+
+ mempool_free(extra_elem, &pool);
+ mempool_exit(&pool);
+}
+
+static void mempool_kmalloc_large_invalid_free(struct kunit *test)
+{
+ mempool_t pool;
+ size_t size = KMALLOC_MAX_CACHE_SIZE + 1;
+ char *extra_elem;
+
+ extra_elem = mempool_prepare_kmalloc(test, &pool, size);
+
+ mempool_kmalloc_invalid_free_helper(test, &pool);
+
+ mempool_free(extra_elem, &pool);
+ mempool_exit(&pool);
+}
+
+/*
+ * Skip the invalid-free test for page mempool. The invalid-free detection only
+ * works for compound pages and mempool preallocates all page elements without
+ * the __GFP_COMP flag.
+ */
+
static char global_array[10];
static void kasan_global_oob_right(struct kunit *test)
@@ -849,53 +1318,6 @@ static void kasan_global_oob_left(struct kunit *test)
KUNIT_EXPECT_KASAN_FAIL(test, *(volatile char *)p);
}
-/* Check that ksize() does NOT unpoison whole object. */
-static void ksize_unpoisons_memory(struct kunit *test)
-{
- char *ptr;
- size_t size = 128 - KASAN_GRANULE_SIZE - 5;
- size_t real_size;
-
- ptr = kmalloc(size, GFP_KERNEL);
- KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
-
- real_size = ksize(ptr);
- KUNIT_EXPECT_GT(test, real_size, size);
-
- OPTIMIZER_HIDE_VAR(ptr);
-
- /* These accesses shouldn't trigger a KASAN report. */
- ptr[0] = 'x';
- ptr[size - 1] = 'x';
-
- /* These must trigger a KASAN report. */
- if (IS_ENABLED(CONFIG_KASAN_GENERIC))
- KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[size]);
- KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[size + 5]);
- KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[real_size - 1]);
-
- 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);
-
- OPTIMIZER_HIDE_VAR(ptr);
- KUNIT_EXPECT_KASAN_FAIL(test, ksize(ptr));
- KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[0]);
- KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[size]);
-}
-
static void kasan_stack_oob(struct kunit *test)
{
char stack_array[10];
@@ -938,69 +1360,6 @@ static void kasan_alloca_oob_right(struct kunit *test)
KUNIT_EXPECT_KASAN_FAIL(test, *(volatile char *)p);
}
-static void kmem_cache_double_free(struct kunit *test)
-{
- char *p;
- size_t size = 200;
- 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__);
- kmem_cache_destroy(cache);
- return;
- }
-
- kmem_cache_free(cache, p);
- KUNIT_EXPECT_KASAN_FAIL(test, kmem_cache_free(cache, p));
- kmem_cache_destroy(cache);
-}
-
-static void kmem_cache_invalid_free(struct kunit *test)
-{
- char *p;
- size_t size = 200;
- struct kmem_cache *cache;
-
- cache = kmem_cache_create("test_cache", size, 0, SLAB_TYPESAFE_BY_RCU,
- 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__);
- kmem_cache_destroy(cache);
- return;
- }
-
- /* Trigger invalid free, the object doesn't get freed. */
- KUNIT_EXPECT_KASAN_FAIL(test, kmem_cache_free(cache, p + 1));
-
- /*
- * Properly free the object to prevent the "Objects remaining in
- * test_cache on __kmem_cache_shutdown" BUG failure.
- */
- kmem_cache_free(cache, p);
-
- kmem_cache_destroy(cache);
-}
-
-static void empty_cache_ctor(void *object) { }
-
-static void kmem_cache_double_destroy(struct kunit *test)
-{
- struct kmem_cache *cache;
-
- /* Provide a constructor to prevent cache merging. */
- cache = kmem_cache_create("test_cache", 200, 0, 0, empty_cache_ctor);
- KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cache);
- kmem_cache_destroy(cache);
- KUNIT_EXPECT_KASAN_FAIL(test, kmem_cache_destroy(cache));
-}
-
static void kasan_memchr(struct kunit *test)
{
char *ptr;
@@ -1162,79 +1521,6 @@ static void kasan_bitops_tags(struct kunit *test)
kfree(bits);
}
-static void kmalloc_double_kzfree(struct kunit *test)
-{
- char *ptr;
- size_t size = 16;
-
- ptr = kmalloc(size, GFP_KERNEL);
- KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
-
- kfree_sensitive(ptr);
- KUNIT_EXPECT_KASAN_FAIL(test, kfree_sensitive(ptr));
-}
-
-/*
- * The two tests below check that Generic KASAN prints auxiliary stack traces
- * for RCU callbacks and workqueues. The reports need to be inspected manually.
- *
- * These tests are still enabled for other KASAN modes to make sure that all
- * modes report bad accesses in tested scenarios.
- */
-
-static struct kasan_rcu_info {
- int i;
- struct rcu_head rcu;
-} *global_rcu_ptr;
-
-static void rcu_uaf_reclaim(struct rcu_head *rp)
-{
- struct kasan_rcu_info *fp =
- container_of(rp, struct kasan_rcu_info, rcu);
-
- kfree(fp);
- ((volatile struct kasan_rcu_info *)fp)->i;
-}
-
-static void rcu_uaf(struct kunit *test)
-{
- struct kasan_rcu_info *ptr;
-
- ptr = kmalloc(sizeof(struct kasan_rcu_info), GFP_KERNEL);
- KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
-
- global_rcu_ptr = rcu_dereference_protected(
- (struct kasan_rcu_info __rcu *)ptr, NULL);
-
- KUNIT_EXPECT_KASAN_FAIL(test,
- call_rcu(&global_rcu_ptr->rcu, rcu_uaf_reclaim);
- rcu_barrier());
-}
-
-static void workqueue_uaf_work(struct work_struct *work)
-{
- kfree(work);
-}
-
-static void workqueue_uaf(struct kunit *test)
-{
- struct workqueue_struct *workqueue;
- struct work_struct *work;
-
- workqueue = create_workqueue("kasan_workqueue_test");
- KUNIT_ASSERT_NOT_ERR_OR_NULL(test, workqueue);
-
- work = kmalloc(sizeof(struct work_struct), GFP_KERNEL);
- KUNIT_ASSERT_NOT_ERR_OR_NULL(test, work);
-
- INIT_WORK(work, workqueue_uaf_work);
- queue_work(workqueue, work);
- destroy_workqueue(workqueue);
-
- KUNIT_EXPECT_KASAN_FAIL(test,
- ((volatile struct work_struct *)work)->data);
-}
-
static void vmalloc_helpers_tags(struct kunit *test)
{
void *ptr;
@@ -1244,6 +1530,9 @@ static void vmalloc_helpers_tags(struct kunit *test)
KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_VMALLOC);
+ if (!kasan_vmalloc_enabled())
+ kunit_skip(test, "Test requires kasan.vmalloc=on");
+
ptr = vmalloc(PAGE_SIZE);
KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
@@ -1278,6 +1567,9 @@ static void vmalloc_oob(struct kunit *test)
KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_VMALLOC);
+ if (!kasan_vmalloc_enabled())
+ kunit_skip(test, "Test requires kasan.vmalloc=on");
+
v_ptr = vmalloc(size);
KUNIT_ASSERT_NOT_ERR_OR_NULL(test, v_ptr);
@@ -1331,6 +1623,9 @@ static void vmap_tags(struct kunit *test)
KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_VMALLOC);
+ if (!kasan_vmalloc_enabled())
+ kunit_skip(test, "Test requires kasan.vmalloc=on");
+
p_page = alloc_pages(GFP_KERNEL, 1);
KUNIT_ASSERT_NOT_ERR_OR_NULL(test, p_page);
p_ptr = page_address(p_page);
@@ -1449,7 +1744,7 @@ static void match_all_not_assigned(struct kunit *test)
free_pages((unsigned long)ptr, order);
}
- if (!IS_ENABLED(CONFIG_KASAN_VMALLOC))
+ if (!kasan_vmalloc_enabled())
return;
for (i = 0; i < 256; i++) {
@@ -1502,6 +1797,14 @@ static void match_all_mem_tag(struct kunit *test)
/* For each possible tag value not matching the pointer tag. */
for (tag = KASAN_TAG_MIN; tag <= KASAN_TAG_KERNEL; tag++) {
+ /*
+ * For Software Tag-Based KASAN, skip the majority of tag
+ * values to avoid the test printing too many reports.
+ */
+ if (IS_ENABLED(CONFIG_KASAN_SW_TAGS) &&
+ tag >= KASAN_TAG_MIN + 8 && tag <= KASAN_TAG_KERNEL - 8)
+ continue;
+
if (tag == get_tag(ptr))
continue;
@@ -1521,16 +1824,16 @@ static struct kunit_case kasan_kunit_test_cases[] = {
KUNIT_CASE(kmalloc_oob_right),
KUNIT_CASE(kmalloc_oob_left),
KUNIT_CASE(kmalloc_node_oob_right),
- 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_big_oob_right),
KUNIT_CASE(kmalloc_large_oob_right),
+ KUNIT_CASE(kmalloc_large_uaf),
+ KUNIT_CASE(kmalloc_large_invalid_free),
+ KUNIT_CASE(page_alloc_oob_right),
+ KUNIT_CASE(page_alloc_uaf),
KUNIT_CASE(krealloc_more_oob),
KUNIT_CASE(krealloc_less_oob),
- KUNIT_CASE(krealloc_pagealloc_more_oob),
- KUNIT_CASE(krealloc_pagealloc_less_oob),
+ KUNIT_CASE(krealloc_large_more_oob),
+ KUNIT_CASE(krealloc_large_less_oob),
KUNIT_CASE(krealloc_uaf),
KUNIT_CASE(kmalloc_oob_16),
KUNIT_CASE(kmalloc_uaf_16),
@@ -1545,29 +1848,41 @@ static struct kunit_case kasan_kunit_test_cases[] = {
KUNIT_CASE(kmalloc_uaf_memset),
KUNIT_CASE(kmalloc_uaf2),
KUNIT_CASE(kmalloc_uaf3),
+ KUNIT_CASE(kmalloc_double_kzfree),
+ KUNIT_CASE(ksize_unpoisons_memory),
+ KUNIT_CASE(ksize_uaf),
+ KUNIT_CASE(rcu_uaf),
+ KUNIT_CASE(workqueue_uaf),
KUNIT_CASE(kfree_via_page),
KUNIT_CASE(kfree_via_phys),
KUNIT_CASE(kmem_cache_oob),
+ KUNIT_CASE(kmem_cache_double_free),
+ KUNIT_CASE(kmem_cache_invalid_free),
+ KUNIT_CASE(kmem_cache_double_destroy),
KUNIT_CASE(kmem_cache_accounted),
KUNIT_CASE(kmem_cache_bulk),
+ KUNIT_CASE(mempool_kmalloc_oob_right),
+ KUNIT_CASE(mempool_kmalloc_large_oob_right),
+ KUNIT_CASE(mempool_slab_oob_right),
+ KUNIT_CASE(mempool_kmalloc_uaf),
+ KUNIT_CASE(mempool_kmalloc_large_uaf),
+ KUNIT_CASE(mempool_slab_uaf),
+ KUNIT_CASE(mempool_page_alloc_uaf),
+ KUNIT_CASE(mempool_kmalloc_double_free),
+ KUNIT_CASE(mempool_kmalloc_large_double_free),
+ KUNIT_CASE(mempool_page_alloc_double_free),
+ KUNIT_CASE(mempool_kmalloc_invalid_free),
+ KUNIT_CASE(mempool_kmalloc_large_invalid_free),
KUNIT_CASE(kasan_global_oob_right),
KUNIT_CASE(kasan_global_oob_left),
KUNIT_CASE(kasan_stack_oob),
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(kmem_cache_double_destroy),
KUNIT_CASE(kasan_memchr),
KUNIT_CASE(kasan_memcmp),
KUNIT_CASE(kasan_strings),
KUNIT_CASE(kasan_bitops_generic),
KUNIT_CASE(kasan_bitops_tags),
- KUNIT_CASE(kmalloc_double_kzfree),
- KUNIT_CASE(rcu_uaf),
- KUNIT_CASE(workqueue_uaf),
KUNIT_CASE(vmalloc_helpers_tags),
KUNIT_CASE(vmalloc_oob),
KUNIT_CASE(vmap_tags),
diff --git a/mm/kasan/quarantine.c b/mm/kasan/quarantine.c
index ca4529156735..6958aa713c67 100644
--- a/mm/kasan/quarantine.c
+++ b/mm/kasan/quarantine.c
@@ -143,11 +143,12 @@ static void *qlink_to_object(struct qlist_node *qlink, struct kmem_cache *cache)
static void qlink_free(struct qlist_node *qlink, struct kmem_cache *cache)
{
void *object = qlink_to_object(qlink, cache);
- struct kasan_free_meta *meta = kasan_get_free_meta(cache, object);
- unsigned long flags;
+ struct kasan_free_meta *free_meta = kasan_get_free_meta(cache, object);
- if (IS_ENABLED(CONFIG_SLAB))
- local_irq_save(flags);
+ /*
+ * Note: Keep per-object metadata to allow KASAN print stack traces for
+ * use-after-free-before-realloc bugs.
+ */
/*
* If init_on_free is enabled and KASAN's free metadata is stored in
@@ -157,18 +158,9 @@ static void qlink_free(struct qlist_node *qlink, struct kmem_cache *cache)
*/
if (slab_want_init_on_free(cache) &&
cache->kasan_info.free_meta_offset == 0)
- memzero_explicit(meta, sizeof(*meta));
-
- /*
- * As the object now gets freed from the quarantine, assume that its
- * free track is no longer valid.
- */
- *(u8 *)kasan_mem_to_shadow(object) = KASAN_SLAB_FREE;
+ memzero_explicit(free_meta, sizeof(*free_meta));
___cache_free(cache, object, _THIS_IP_);
-
- if (IS_ENABLED(CONFIG_SLAB))
- local_irq_restore(flags);
}
static void qlist_free_all(struct qlist_head *q, struct kmem_cache *cache)
diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index e77facb62900..7afa4feb03e1 100644
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -23,6 +23,7 @@
#include <linux/stacktrace.h>
#include <linux/string.h>
#include <linux/types.h>
+#include <linux/vmalloc.h>
#include <linux/kasan.h>
#include <linux/module.h>
#include <linux/sched/task_stack.h>
@@ -262,7 +263,19 @@ static void print_error_description(struct kasan_report_info *info)
static void print_track(struct kasan_track *track, const char *prefix)
{
+#ifdef CONFIG_KASAN_EXTRA_INFO
+ u64 ts_nsec = track->timestamp;
+ unsigned long rem_usec;
+
+ ts_nsec <<= 3;
+ rem_usec = do_div(ts_nsec, NSEC_PER_SEC) / 1000;
+
+ pr_err("%s by task %u on cpu %d at %lu.%06lus:\n",
+ prefix, track->pid, track->cpu,
+ (unsigned long)ts_nsec, rem_usec);
+#else
pr_err("%s by task %u:\n", prefix, track->pid);
+#endif /* CONFIG_KASAN_EXTRA_INFO */
if (track->stack)
stack_depot_print(track->stack);
else
@@ -623,37 +636,43 @@ void kasan_report_async(void)
#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
/*
- * With CONFIG_KASAN_INLINE, accesses to bogus pointers (outside the high
- * canonical half of the address space) cause out-of-bounds shadow memory reads
- * before the actual access. For addresses in the low canonical half of the
- * address space, as well as most non-canonical addresses, that out-of-bounds
- * shadow memory access lands in the non-canonical part of the address space.
- * Help the user figure out what the original bogus pointer was.
+ * With compiler-based KASAN modes, accesses to bogus pointers (outside of the
+ * mapped kernel address space regions) cause faults when KASAN tries to check
+ * the shadow memory before the actual memory access. This results in cryptic
+ * GPF reports, which are hard for users to interpret. This hook helps users to
+ * figure out what the original bogus pointer was.
*/
void kasan_non_canonical_hook(unsigned long addr)
{
unsigned long orig_addr;
const char *bug_type;
+ /*
+ * All addresses that came as a result of the memory-to-shadow mapping
+ * (even for bogus pointers) must be >= KASAN_SHADOW_OFFSET.
+ */
if (addr < KASAN_SHADOW_OFFSET)
return;
- orig_addr = (addr - KASAN_SHADOW_OFFSET) << KASAN_SHADOW_SCALE_SHIFT;
+ orig_addr = (unsigned long)kasan_shadow_to_mem((void *)addr);
+
/*
* For faults near the shadow address for NULL, we can be fairly certain
* that this is a KASAN shadow memory access.
- * For faults that correspond to shadow for low canonical addresses, we
- * can still be pretty sure - that shadow region is a fairly narrow
- * chunk of the non-canonical address space.
- * But faults that look like shadow for non-canonical addresses are a
- * really large chunk of the address space. In that case, we still
- * print the decoded address, but make it clear that this is not
- * necessarily what's actually going on.
+ * For faults that correspond to the shadow for low or high canonical
+ * addresses, we can still be pretty sure: these shadow regions are a
+ * fairly narrow chunk of the address space.
+ * But the shadow for non-canonical addresses is a really large chunk
+ * of the address space. For this case, we still print the decoded
+ * address, but make it clear that this is not necessarily what's
+ * actually going on.
*/
if (orig_addr < PAGE_SIZE)
bug_type = "null-ptr-deref";
else if (orig_addr < TASK_SIZE)
bug_type = "probably user-memory-access";
+ else if (addr_in_shadow((void *)addr))
+ bug_type = "probably wild-memory-access";
else
bug_type = "maybe wild-memory-access";
pr_alert("KASAN: %s in range [0x%016lx-0x%016lx]\n", bug_type,
diff --git a/mm/kasan/report_generic.c b/mm/kasan/report_generic.c
index 99cbcd73cff7..f5b8e37b3805 100644
--- a/mm/kasan/report_generic.c
+++ b/mm/kasan/report_generic.c
@@ -110,7 +110,7 @@ static const char *get_shadow_bug_type(struct kasan_report_info *info)
bug_type = "use-after-free";
break;
case KASAN_SLAB_FREE:
- case KASAN_SLAB_FREETRACK:
+ case KASAN_SLAB_FREE_META:
bug_type = "slab-use-after-free";
break;
case KASAN_ALLOCA_LEFT:
@@ -173,8 +173,8 @@ void kasan_complete_mode_report_info(struct kasan_report_info *info)
memcpy(&info->alloc_track, &alloc_meta->alloc_track,
sizeof(info->alloc_track));
- if (*(u8 *)kasan_mem_to_shadow(info->object) == KASAN_SLAB_FREETRACK) {
- /* Free meta must be present with KASAN_SLAB_FREETRACK. */
+ if (*(u8 *)kasan_mem_to_shadow(info->object) == KASAN_SLAB_FREE_META) {
+ /* Free meta must be present with KASAN_SLAB_FREE_META. */
free_meta = kasan_get_free_meta(info->cache, info->object);
memcpy(&info->free_track, &free_meta->free_track,
sizeof(info->free_track));
diff --git a/mm/kasan/report_tags.c b/mm/kasan/report_tags.c
index 8b8bfdb3cfdb..d15f8f580e2c 100644
--- a/mm/kasan/report_tags.c
+++ b/mm/kasan/report_tags.c
@@ -7,6 +7,7 @@
#include <linux/atomic.h>
#include "kasan.h"
+#include "../slab.h"
extern struct kasan_stack_ring stack_ring;
@@ -31,10 +32,6 @@ void kasan_complete_mode_report_info(struct kasan_report_info *info)
unsigned long flags;
u64 pos;
struct kasan_stack_ring_entry *entry;
- void *ptr;
- u32 pid;
- depot_stack_handle_t stack;
- bool is_free;
bool alloc_found = false, free_found = false;
if ((!info->cache || !info->object) && !info->bug_type) {
@@ -61,18 +58,12 @@ void kasan_complete_mode_report_info(struct kasan_report_info *info)
entry = &stack_ring.entries[i % stack_ring.size];
- /* Paired with smp_store_release() in save_stack_info(). */
- ptr = (void *)smp_load_acquire(&entry->ptr);
-
- if (kasan_reset_tag(ptr) != info->object ||
- get_tag(ptr) != get_tag(info->access_addr))
+ if (kasan_reset_tag(entry->ptr) != info->object ||
+ get_tag(entry->ptr) != get_tag(info->access_addr) ||
+ info->cache->object_size != entry->size)
continue;
- pid = READ_ONCE(entry->pid);
- stack = READ_ONCE(entry->stack);
- is_free = READ_ONCE(entry->is_free);
-
- if (is_free) {
+ if (entry->is_free) {
/*
* Second free of the same object.
* Give up on trying to find the alloc entry.
@@ -80,8 +71,8 @@ void kasan_complete_mode_report_info(struct kasan_report_info *info)
if (free_found)
break;
- info->free_track.pid = pid;
- info->free_track.stack = stack;
+ memcpy(&info->free_track, &entry->track,
+ sizeof(info->free_track));
free_found = true;
/*
@@ -95,8 +86,8 @@ void kasan_complete_mode_report_info(struct kasan_report_info *info)
if (alloc_found)
break;
- info->alloc_track.pid = pid;
- info->alloc_track.stack = stack;
+ memcpy(&info->alloc_track, &entry->track,
+ sizeof(info->alloc_track));
alloc_found = true;
/*
diff --git a/mm/kasan/shadow.c b/mm/kasan/shadow.c
index d687f09a7ae3..9ef84f31833f 100644
--- a/mm/kasan/shadow.c
+++ b/mm/kasan/shadow.c
@@ -130,15 +130,11 @@ void kasan_poison(const void *addr, size_t size, u8 value, bool init)
/*
* Perform shadow offset calculation based on untagged address, as
- * some of the callers (e.g. kasan_poison_object_data) pass tagged
+ * some of the callers (e.g. kasan_poison_new_object) pass tagged
* addresses to this function.
*/
addr = kasan_reset_tag(addr);
- /* Skip KFENCE memory if called explicitly outside of sl*b. */
- if (is_kfence_address(addr))
- return;
-
if (WARN_ON((unsigned long)addr & KASAN_GRANULE_MASK))
return;
if (WARN_ON(size & KASAN_GRANULE_MASK))
@@ -149,7 +145,7 @@ void kasan_poison(const void *addr, size_t size, u8 value, bool init)
__memset(shadow_start, value, shadow_end - shadow_start);
}
-EXPORT_SYMBOL(kasan_poison);
+EXPORT_SYMBOL_GPL(kasan_poison);
#ifdef CONFIG_KASAN_GENERIC
void kasan_poison_last_granule(const void *addr, size_t size)
@@ -170,19 +166,11 @@ void kasan_unpoison(const void *addr, size_t size, bool init)
/*
* Perform shadow offset calculation based on untagged address, as
- * some of the callers (e.g. kasan_unpoison_object_data) pass tagged
+ * some of the callers (e.g. kasan_unpoison_new_object) pass tagged
* addresses to this function.
*/
addr = kasan_reset_tag(addr);
- /*
- * Skip KFENCE memory if called explicitly outside of sl*b. Also note
- * that calls to ksize(), where size is not a multiple of machine-word
- * size, would otherwise poison the invalid portion of the word.
- */
- if (is_kfence_address(addr))
- return;
-
if (WARN_ON((unsigned long)addr & KASAN_GRANULE_MASK))
return;
diff --git a/mm/kasan/tags.c b/mm/kasan/tags.c
index 7dcfe341d48e..d65d48b85f90 100644
--- a/mm/kasan/tags.c
+++ b/mm/kasan/tags.c
@@ -13,6 +13,8 @@
#include <linux/memblock.h>
#include <linux/memory.h>
#include <linux/mm.h>
+#include <linux/sched/clock.h>
+#include <linux/stackdepot.h>
#include <linux/static_key.h>
#include <linux/string.h>
#include <linux/types.h>
@@ -96,12 +98,13 @@ static void save_stack_info(struct kmem_cache *cache, void *object,
gfp_t gfp_flags, bool is_free)
{
unsigned long flags;
- depot_stack_handle_t stack;
+ depot_stack_handle_t stack, old_stack;
u64 pos;
struct kasan_stack_ring_entry *entry;
void *old_ptr;
- stack = kasan_save_stack(gfp_flags, true);
+ stack = kasan_save_stack(gfp_flags,
+ STACK_DEPOT_FLAG_CAN_ALLOC | STACK_DEPOT_FLAG_GET);
/*
* Prevent save_stack_info() from modifying stack ring
@@ -120,17 +123,18 @@ next:
if (!try_cmpxchg(&entry->ptr, &old_ptr, STACK_RING_BUSY_PTR))
goto next; /* Busy slot. */
- WRITE_ONCE(entry->size, cache->object_size);
- WRITE_ONCE(entry->pid, current->pid);
- WRITE_ONCE(entry->stack, stack);
- WRITE_ONCE(entry->is_free, is_free);
+ old_stack = entry->track.stack;
- /*
- * Paired with smp_load_acquire() in kasan_complete_mode_report_info().
- */
- smp_store_release(&entry->ptr, (s64)object);
+ entry->size = cache->object_size;
+ kasan_set_track(&entry->track, stack);
+ entry->is_free = is_free;
+
+ entry->ptr = object;
read_unlock_irqrestore(&stack_ring.lock, flags);
+
+ if (old_stack)
+ stack_depot_put(old_stack);
}
void kasan_save_alloc_info(struct kmem_cache *cache, void *object, gfp_t flags)