From: Marco Elver <elver@google.com>
To: andrey.konovalov@linux.dev
Cc: Andrew Morton <akpm@linux-foundation.org>,
Andrey Konovalov <andreyknvl@gmail.com>,
Andrey Ryabinin <aryabinin@virtuozzo.com>,
Dmitry Vyukov <dvyukov@google.com>,
Alexander Potapenko <glider@google.com>,
kasan-dev@googlegroups.com, linux-mm@kvack.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 8/8] kasan: test: avoid corrupting memory in kasan_rcu_uaf
Date: Thu, 12 Aug 2021 10:50:30 +0200 [thread overview]
Message-ID: <CANpmjNOf=XzX1xhjaz7+SBN2HYq+9jH4EcHi4gfwjSyTa3q00w@mail.gmail.com> (raw)
In-Reply-To: <da8d30df9206b54be2768b27bb026ec06e4da7a4.1628709663.git.andreyknvl@gmail.com>
On Wed, 11 Aug 2021 at 21:34, <andrey.konovalov@linux.dev> wrote:
>
> 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>
Reviewed-by: Marco Elver <elver@google.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
>
next prev parent reply other threads:[~2021-08-12 8:50 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-11 19:21 [PATCH 0/8] kasan: test: avoid crashing the kernel with HW_TAGS andrey.konovalov
2021-08-11 19:21 ` [PATCH 1/8] kasan: test: rework kmalloc_oob_right andrey.konovalov
2021-08-12 8:57 ` Marco Elver
2021-08-11 19:21 ` [PATCH 2/8] kasan: test: avoid writing invalid memory andrey.konovalov
2021-08-12 8:57 ` Marco Elver
2021-08-12 13:02 ` Andrey Konovalov
2021-08-11 19:21 ` [PATCH 3/8] kasan: test: avoid corrupting memory via memset andrey.konovalov
2021-08-12 8:56 ` Marco Elver
2021-08-12 12:55 ` Andrey Konovalov
2021-08-11 19:21 ` [PATCH 4/8] kasan: test: disable kmalloc_memmove_invalid_size for HW_TAGS andrey.konovalov
2021-08-12 8:57 ` Marco Elver
2021-08-11 19:21 ` [PATCH 5/8] kasan: test: only do kmalloc_uaf_memset for generic mode andrey.konovalov
2021-08-12 8:56 ` Marco Elver
2021-08-11 19:23 ` [PATCH 6/8] kasan: test: clean up ksize_uaf andrey.konovalov
2021-08-12 8:56 ` Marco Elver
2021-08-11 19:30 ` [PATCH 7/8] kasan: test: avoid corrupting memory in copy_user_test andrey.konovalov
2021-08-12 8:50 ` Marco Elver
2021-08-11 19:34 ` [PATCH 8/8] kasan: test: avoid corrupting memory in kasan_rcu_uaf andrey.konovalov
2021-08-12 8:50 ` Marco Elver [this message]
2021-08-12 8:58 ` [PATCH 0/8] kasan: test: avoid crashing the kernel with HW_TAGS Marco Elver
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