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| author | Andrey Ryabinin <aryabinin@virtuozzo.com> | 2016-08-02 14:02:52 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-08-02 17:31:41 -0400 |
| commit | b3cbd9bf77cd1888114dbee1653e79aa23fd4068 (patch) | |
| tree | f9a10e2c14b336f276805f8a4714d0bd437d1646 /mm/slab.c | |
| parent | 47b5c2a0f021e90a79845d1a1353780e5edd0bce (diff) | |
| download | linux-0-day-b3cbd9bf77cd1888114dbee1653e79aa23fd4068.tar.gz linux-0-day-b3cbd9bf77cd1888114dbee1653e79aa23fd4068.tar.xz | |
mm/kasan: get rid of ->state in struct kasan_alloc_meta
The state of object currently tracked in two places - shadow memory, and
the ->state field in struct kasan_alloc_meta. We can get rid of the
latter. The will save us a little bit of memory. Also, this allow us
to move free stack into struct kasan_alloc_meta, without increasing
memory consumption. So now we should always know when the last time the
object was freed. This may be useful for long delayed use-after-free
bugs.
As a side effect this fixes following UBSAN warning:
UBSAN: Undefined behaviour in mm/kasan/quarantine.c:102:13
member access within misaligned address ffff88000d1efebc for type 'struct qlist_node'
which requires 8 byte alignment
Link: http://lkml.kernel.org/r/1470062715-14077-5-git-send-email-aryabinin@virtuozzo.com
Reported-by: kernel test robot <xiaolong.ye@intel.com>
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/slab.c')
| -rw-r--r-- | mm/slab.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/mm/slab.c b/mm/slab.c index 09771ed3e6932..ca135bd47c351 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -2604,9 +2604,11 @@ static void cache_init_objs(struct kmem_cache *cachep, } for (i = 0; i < cachep->num; i++) { + objp = index_to_obj(cachep, page, i); + kasan_init_slab_obj(cachep, objp); + /* constructor could break poison info */ if (DEBUG == 0 && cachep->ctor) { - objp = index_to_obj(cachep, page, i); kasan_unpoison_object_data(cachep, objp); cachep->ctor(objp); kasan_poison_object_data(cachep, objp); |