diff options
| author | Walter Wu <walter-zh.wu@mediatek.com> | 2020-12-29 15:14:46 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-12-29 15:36:49 -0800 |
| commit | 13384f6125ad7ebdcc8914fe1e03ded48ce76581 (patch) | |
| tree | cae4018d6848478cb6fcbb1f312e2e21044d7ee0 /mm | |
| parent | 111fe7186b29d172729db5e294875b9fc7a0ec1d (diff) | |
kasan: fix null pointer dereference in kasan_record_aux_stack
Syzbot reported the following [1]:
BUG: kernel NULL pointer dereference, address: 0000000000000008
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 2d993067 P4D 2d993067 PUD 19a3c067 PMD 0
Oops: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 3852 Comm: kworker/1:2 Not tainted 5.10.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events free_ipc
RIP: 0010:kasan_record_aux_stack+0x77/0xb0
Add null checking slab object from kasan_get_alloc_meta() in order to
avoid null pointer dereference.
[1] https://syzkaller.appspot.com/x/log.txt?x=10a82a50d00000
Link: https://lkml.kernel.org/r/20201228080018.23041-1-walter-zh.wu@mediatek.com
Signed-off-by: Walter Wu <walter-zh.wu@mediatek.com>
Suggested-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Alexander Potapenko <glider@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/kasan/generic.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c index 1dd5a0f99372..5106b84b07d4 100644 --- a/mm/kasan/generic.c +++ b/mm/kasan/generic.c @@ -337,6 +337,8 @@ void kasan_record_aux_stack(void *addr) cache = page->slab_cache; object = nearest_obj(cache, page, addr); alloc_meta = kasan_get_alloc_meta(cache, object); + if (!alloc_meta) + return; alloc_meta->aux_stack[1] = alloc_meta->aux_stack[0]; alloc_meta->aux_stack[0] = kasan_save_stack(GFP_NOWAIT); |