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| author | Paul Lawrence <paullawrence@google.com> | 2018-02-06 15:36:11 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-02-06 18:32:42 -0800 |
| commit | 342061ee4ef3d80001d1ae494378f3979c861dba (patch) | |
| tree | 0441486ae0c2df8e8edad38a70aa62515235eb02 /mm/kasan/kasan.h | |
| parent | 1a69e7ce8391a8bc808baf04e06d88ab4024ca47 (diff) | |
| download | linux-342061ee4ef3d80001d1ae494378f3979c861dba.tar.gz linux-342061ee4ef3d80001d1ae494378f3979c861dba.tar.bz2 linux-342061ee4ef3d80001d1ae494378f3979c861dba.zip | |
kasan: support alloca() poisoning
clang's AddressSanitizer implementation adds redzones on either side of
alloca()ed buffers. These redzones are 32-byte aligned and at least 32
bytes long.
__asan_alloca_poison() is passed the size and address of the allocated
buffer, *excluding* the redzones on either side. The left redzone will
always be to the immediate left of this buffer; but AddressSanitizer may
need to add padding between the end of the buffer and the right redzone.
If there are any 8-byte chunks inside this padding, we should poison
those too.
__asan_allocas_unpoison() is just passed the top and bottom of the dynamic
stack area, so unpoisoning is simpler.
Link: http://lkml.kernel.org/r/20171204191735.132544-4-paullawrence@google.com
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Paul Lawrence <paullawrence@google.com>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/kasan/kasan.h')
| -rw-r--r-- | mm/kasan/kasan.h | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h index c70851a9a6a4..7c0bcd1f4c0d 100644 --- a/mm/kasan/kasan.h +++ b/mm/kasan/kasan.h @@ -24,6 +24,14 @@ #define KASAN_STACK_PARTIAL 0xF4 #define KASAN_USE_AFTER_SCOPE 0xF8 +/* + * alloca redzone shadow values + */ +#define KASAN_ALLOCA_LEFT 0xCA +#define KASAN_ALLOCA_RIGHT 0xCB + +#define KASAN_ALLOCA_REDZONE_SIZE 32 + /* Don't break randconfig/all*config builds */ #ifndef KASAN_ABI_VERSION #define KASAN_ABI_VERSION 1 |