kasan: Fix a type conversion error
The current KASAN code can not find the following out-of-bounds bugs:
char *ptr;
ptr = kmalloc(8, GFP_KERNEL);
memset(ptr+7, 0, 2);
the cause of the problem is the type conversion error in
*memory_is_poisoned_n* function. So this patch fix that.
Signed-off-by: Wang Long <long.wanglong@huawei.com>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/kasan/kasan.c b/mm/kasan/kasan.c
index 21c50dc..2b21ccd 100644
--- a/mm/kasan/kasan.c
+++ b/mm/kasan/kasan.c
@@ -203,7 +203,7 @@
s8 *last_shadow = (s8 *)kasan_mem_to_shadow((void *)last_byte);
if (unlikely(ret != (unsigned long)last_shadow ||
- ((last_byte & KASAN_SHADOW_MASK) >= *last_shadow)))
+ ((long)(last_byte & KASAN_SHADOW_MASK) >= *last_shadow)))
return true;
}
return false;
