lkml.org 
[lkml]   [2015]   [Sep]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH] kasan: fix last shadow judgement in memory_is_poisoned_16()
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



\
 
 \ /
  Last update: 2015-09-08 04:01    [W:0.070 / U:0.124 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site