Messages in this thread Patch in this message | | | Date | Tue, 8 Sep 2015 09:42:27 +0800 | From | Xishi Qiu <> | Subject | [PATCH] kasan: fix last shadow judgement in memory_is_poisoned_16() |
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The shadow which correspond 16 bytes may span 2 or 3 bytes. If shadow only take 2 bytes, we can return in "if (likely(!last_byte)) ...", but it calculates wrong, so fix it.
Signed-off-by: Xishi Qiu <qiuxishi@huawei.com> --- mm/kasan/kasan.c | 3 +-- 1 files changed, 1 insertions(+), 2 deletions(-)
diff --git a/mm/kasan/kasan.c b/mm/kasan/kasan.c index 7b28e9c..8da2114 100644 --- a/mm/kasan/kasan.c +++ b/mm/kasan/kasan.c @@ -135,12 +135,11 @@ static __always_inline bool memory_is_poisoned_16(unsigned long addr) if (unlikely(*shadow_addr)) { u16 shadow_first_bytes = *(u16 *)shadow_addr; - s8 last_byte = (addr + 15) & KASAN_SHADOW_MASK; if (unlikely(shadow_first_bytes)) return true; - if (likely(!last_byte)) + if (likely(IS_ALIGNED(addr, 8))) return false; return memory_is_poisoned_1(addr + 15); -- 1.7.1
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