mbox series

[v3,0/1] kasan: fix redzone overwritten issue under SLUB debug

Message ID 20210630134943.20781-1-yee.lee@mediatek.com (mailing list archive)
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Series kasan: fix redzone overwritten issue under SLUB debug | expand

Message

Yee Lee (李建誼) June 30, 2021, 1:49 p.m. UTC 
From: Yee Lee <yee.lee@mediatek.com>

Issue: In SLUB debug, hwtag kasan_unpoison() would overwrite the redzone
 in those objects with unaligned size.

This patch Adds memzero_explict() to separate the initialization for
such condition. The new code path is executed about 1.1% during nromal
booting process. The penalty is acceptable since it only works in debug mode.


=============
Exp: QEMUv5.2(+mte)/SLUB_debug mode
code path exec : 941/80854 (1.1%)
---
Changed since v2:
 - Use if-statement to refine the condition block instead of preprocessor #if
 - Add comment block about this new code path in source code.

---
Changed since v1:
 - Apply IS_ENABLED to wrap codes under SLUB debug mode.
 - Replace memset() by memzero_explict().

---

Yee Lee (1):
  kasan: Add memzero init for unaligned size under SLUB debug

 mm/kasan/kasan.h | 10 ++++++++++
 1 file changed, 10 insertions(+)