kasan: fix last shadow judgement in memory_is_poisoned_16()
The shadow which correspond 16 bytes memory may span 2 or 3 bytes. If
the memory is aligned on 8, then the shadow takes only 2 bytes. So we
check "shadow_first_bytes" is enough, and need not to call
"memory_is_poisoned_1(addr + 15);". But the code "if
(likely(!last_byte))" is wrong judgement.
e.g. addr=0, so last_byte = 15 & KASAN_SHADOW_MASK = 7, then the code
will continue to call "memory_is_poisoned_1(addr + 15);"
Signed-off-by: Xishi Qiu <qiuxishi@huawei.com>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Andrey Konovalov <adech.fo@gmail.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Michal Marek <mmarek@suse.cz>
Cc: <zhongjiang@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 file changed
