From: "Theodore Ts'o" <tytso@mit.edu>
To: linux-ext4@vger.kernel.org, Zhang Yi <yi.zhang@huawei.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>,
jack@suse.cz, adilger.kernel@dilger.ca, yukuai3@huawei.com
Subject: Re: [PATCH] ext4: fix an use-after-free issue about data=journal writeback mode
Date: Mon, 27 Dec 2021 10:16:24 -0500 [thread overview]
Message-ID: <164061813992.3186289.16531799470914194648.b4-ty@mit.edu> (raw)
In-Reply-To: <20211225090937.712867-1-yi.zhang@huawei.com>
On Sat, 25 Dec 2021 17:09:37 +0800, Zhang Yi wrote:
> Our syzkaller report an use-after-free issue that accessing the freed
> buffer_head on the writeback page in __ext4_journalled_writepage(). The
> problem is that if there was a truncate racing with the data=journalled
> writeback procedure, the writeback length could become zero and
> bget_one() refuse to get buffer_head's refcount, then the truncate
> procedure release buffer once we drop page lock, finally, the last
> ext4_walk_page_buffers() trigger the use-after-free problem.
>
> [...]
Nice catch. Applied, thanks!
[1/1] ext4: fix an use-after-free issue about data=journal writeback mode
commit: 856dd2096e2a01f6eb2c9d60f6e0cd587aa273a8
Best regards,
--
Theodore Ts'o <tytso@mit.edu>
prev parent reply other threads:[~2021-12-27 15:16 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-25 9:09 [PATCH] ext4: fix an use-after-free issue about data=journal writeback mode Zhang Yi
2021-12-27 15:16 ` Theodore Ts'o [this message]
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