kasan: detect invalid frees for large mempool objects

Detect frees of pointers into middle of mempool objects.

I did a one-off test, but it turned out to be very tricky, so I reverted
it.  First, mempool does not call kasan_poison_kfree() unless allocation
function fails.  I stubbed an allocation function to fail on second and
subsequent allocations.  But then mempool stopped to call
kasan_poison_kfree() at all, because it does it only when allocation
function is mempool_kmalloc().  We could support this special failing
test allocation function in mempool, but it also can't live with kasan
tests, because these are in a module.

Link: http://lkml.kernel.org/r/bf7a7d035d7a5ed62d2dd0e3d2e8a4fcdf456aa7.1514378558.git.dvyukov@google.com
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>a
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Dmitry Vyukov
2018-02-06 15:36:30 -08:00
committed by Linus Torvalds
parent ee3ce779b5
commit 6860f6340c
3 changed files with 13 additions and 8 deletions

View File

@@ -57,7 +57,7 @@ void kasan_init_slab_obj(struct kmem_cache *cache, const void *object);
void kasan_kmalloc_large(const void *ptr, size_t size, gfp_t flags);
void kasan_kfree_large(void *ptr, unsigned long ip);
void kasan_poison_kfree(void *ptr);
void kasan_poison_kfree(void *ptr, unsigned long ip);
void kasan_kmalloc(struct kmem_cache *s, const void *object, size_t size,
gfp_t flags);
void kasan_krealloc(const void *object, size_t new_size, gfp_t flags);
@@ -109,7 +109,7 @@ static inline void kasan_init_slab_obj(struct kmem_cache *cache,
static inline void kasan_kmalloc_large(void *ptr, size_t size, gfp_t flags) {}
static inline void kasan_kfree_large(void *ptr, unsigned long ip) {}
static inline void kasan_poison_kfree(void *ptr) {}
static inline void kasan_poison_kfree(void *ptr, unsigned long ip) {}
static inline void kasan_kmalloc(struct kmem_cache *s, const void *object,
size_t size, gfp_t flags) {}
static inline void kasan_krealloc(const void *object, size_t new_size,