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| author | Andrey Konovalov <andreyknvl@google.com> | 2019-02-20 22:19:01 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-02-21 09:01:00 -0800 |
| commit | e1db95befb3e9e3476629afec6e0f5d0707b9825 (patch) | |
| tree | 58475361bb36b550daf852b6121d663e1343069d /mm/kasan | |
| parent | 050c17f239fd53adb55aa768d4f41bc76c0fe045 (diff) | |
| download | linux-e1db95befb3e9e3476629afec6e0f5d0707b9825.tar.bz2 | |
kasan: fix assigning tags twice
When an object is kmalloc()'ed, two hooks are called: kasan_slab_alloc()
and kasan_kmalloc(). Right now we assign a tag twice, once in each of the
hooks. Fix it by assigning a tag only in the former hook.
Link: http://lkml.kernel.org/r/ce8c6431da735aa7ec051fd6497153df690eb021.1549921721.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgeniy Stepanov <eugenis@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kostya Serebryany <kcc@google.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Qian Cai <cai@lca.pw>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/kasan')
| -rw-r--r-- | mm/kasan/common.c | 29 |
1 files changed, 17 insertions, 12 deletions
diff --git a/mm/kasan/common.c b/mm/kasan/common.c index 73c9cbfdedf4..09b534fbba17 100644 --- a/mm/kasan/common.c +++ b/mm/kasan/common.c @@ -361,10 +361,15 @@ void kasan_poison_object_data(struct kmem_cache *cache, void *object) * get different tags. */ static u8 assign_tag(struct kmem_cache *cache, const void *object, - bool init, bool krealloc) + bool init, bool keep_tag) { - /* Reuse the same tag for krealloc'ed objects. */ - if (krealloc) + /* + * 1. When an object is kmalloc()'ed, two hooks are called: + * kasan_slab_alloc() and kasan_kmalloc(). We assign the + * tag only in the first one. + * 2. We reuse the same tag for krealloc'ed objects. + */ + if (keep_tag) return get_tag(object); /* @@ -405,12 +410,6 @@ void * __must_check kasan_init_slab_obj(struct kmem_cache *cache, return (void *)object; } -void * __must_check kasan_slab_alloc(struct kmem_cache *cache, void *object, - gfp_t flags) -{ - return kasan_kmalloc(cache, object, cache->object_size, flags); -} - static inline bool shadow_invalid(u8 tag, s8 shadow_byte) { if (IS_ENABLED(CONFIG_KASAN_GENERIC)) @@ -467,7 +466,7 @@ bool kasan_slab_free(struct kmem_cache *cache, void *object, unsigned long ip) } static void *__kasan_kmalloc(struct kmem_cache *cache, const void *object, - size_t size, gfp_t flags, bool krealloc) + size_t size, gfp_t flags, bool keep_tag) { unsigned long redzone_start; unsigned long redzone_end; @@ -485,7 +484,7 @@ static void *__kasan_kmalloc(struct kmem_cache *cache, const void *object, KASAN_SHADOW_SCALE_SIZE); if (IS_ENABLED(CONFIG_KASAN_SW_TAGS)) - tag = assign_tag(cache, object, false, krealloc); + tag = assign_tag(cache, object, false, keep_tag); /* Tag is ignored in set_tag without CONFIG_KASAN_SW_TAGS */ kasan_unpoison_shadow(set_tag(object, tag), size); @@ -498,10 +497,16 @@ static void *__kasan_kmalloc(struct kmem_cache *cache, const void *object, return set_tag(object, tag); } +void * __must_check kasan_slab_alloc(struct kmem_cache *cache, void *object, + gfp_t flags) +{ + return __kasan_kmalloc(cache, object, cache->object_size, flags, false); +} + 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, false); + return __kasan_kmalloc(cache, object, size, flags, true); } EXPORT_SYMBOL(kasan_kmalloc); |