Messages in this thread Patch in this message | | | From | Sasha Levin <> | Subject | [PATCH AUTOSEL 5.10 53/53] kasan: test: avoid corrupting memory in kasan_rcu_uaf | Date | Thu, 9 Sep 2021 20:20:28 -0400 |
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From: Andrey Konovalov <andreyknvl@gmail.com>
[ Upstream commit f16de0bcdb55bf18e2533ca625f3e4b4952f254c ]
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.
Link: https://lkml.kernel.org/r/b6f2c3bf712d2457c783fa59498225b66a634f62.1628779805.git.andreyknvl@gmail.com Signed-off-by: Andrey Konovalov <andreyknvl@gmail.com> Reviewed-by: Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> --- 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 2d68db6ae67b..1c6e06136f78 100644 --- a/lib/test_kasan_module.c +++ b/lib/test_kasan_module.c @@ -73,7 +73,7 @@ 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) -- 2.30.2
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