lkml.org 
[lkml]   [2021]   [Aug]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v2 8/8] kasan: test: avoid corrupting memory in kasan_rcu_uaf
Date
From: Andrey Konovalov <andreyknvl@gmail.com>

kasan_rcu_uaf() writes to freed memory via kasan_rcu_reclaim(), which is
only safe with the GENERIC mode (as it uses quarantine). For other modes,
this test corrupts kernel memory, which might result in a crash.

Turn the write into a read.

Signed-off-by: Andrey Konovalov <andreyknvl@gmail.com>
---
lib/test_kasan_module.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/test_kasan_module.c b/lib/test_kasan_module.c
index fa73b9df0be4..7ebf433edef3 100644
--- a/lib/test_kasan_module.c
+++ b/lib/test_kasan_module.c
@@ -71,7 +71,7 @@ static noinline void __init kasan_rcu_reclaim(struct rcu_head *rp)
struct kasan_rcu_info, rcu);

kfree(fp);
- fp->i = 1;
+ ((volatile struct kasan_rcu_info *)fp)->i;
}

static noinline void __init kasan_rcu_uaf(void)
--
2.25.1
\
 
 \ /
  Last update: 2021-08-12 17:06    [W:0.056 / U:0.388 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site