From: Andreas Gruenbacher <agruenba@redhat.com>
To: Juntong Deng <juntong.deng@outlook.com>
Cc: rpeterso@redhat.com, gfs2@lists.linux.dev,
linux-kernel@vger.kernel.org,
linux-kernel-mentees@lists.linuxfoundation.org,
syzbot+29c47e9e51895928698c@syzkaller.appspotmail.com
Subject: Re: [PATCH] fs/gfs2: Fix slab-use-after-free in gfs2_qd_dealloc
Date: Mon, 30 Oct 2023 23:38:24 +0100 [thread overview]
Message-ID: <CAHc6FU41DktH6+Hxsv3kYSiXenjoLJ58P6+mO9Yjhex5M0=aVA@mail.gmail.com> (raw)
In-Reply-To: <VI1P193MB0752B3C3E2DF69C56BF5D6D199A2A@VI1P193MB0752.EURP193.PROD.OUTLOOK.COM>
Hello Juntong,
On Sun, Oct 29, 2023 at 10:11 PM Juntong Deng <juntong.deng@outlook.com> wrote:
> In gfs2_put_super(), whether withdrawn or not, the quota should
> be cleaned up by gfs2_quota_cleanup() and wait for all quota to
> be deallocated.
>
> Otherwise struct gfs2_sbd has been freed before gfs2_qd_dealloc
> (rcu callback) is completed, resulting in use-after-free.
>
> Also, gfs2_destroy_threads() and gfs2_quota_cleanup() have
> already been called in gfs2_make_fs_ro(), so there is no need to
> call them again subsequently, whether withdrawn or not.
>
> Reported-by: syzbot+29c47e9e51895928698c@syzkaller.appspotmail.com
> Closes: https://syzkaller.appspot.com/bug?extid=29c47e9e51895928698c
> Signed-off-by: Juntong Deng <juntong.deng@outlook.com>
> ---
> fs/gfs2/super.c | 10 ++++++----
> 1 file changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/fs/gfs2/super.c b/fs/gfs2/super.c
> index a4b3655c5361..d21c04a22d73 100644
> --- a/fs/gfs2/super.c
> +++ b/fs/gfs2/super.c
> @@ -602,13 +602,15 @@ static void gfs2_put_super(struct super_block *sb)
> }
> spin_unlock(&sdp->sd_jindex_spin);
>
> - if (!sb_rdonly(sb)) {
> + if (!sb_rdonly(sb))
> gfs2_make_fs_ro(sdp);
> - }
> - if (gfs2_withdrawn(sdp)) {
> - gfs2_destroy_threads(sdp);
> + else {
> + if (gfs2_withdrawn(sdp))
> + gfs2_destroy_threads(sdp);
> +
> gfs2_quota_cleanup(sdp);
> }
> +
> WARN_ON(gfs2_withdrawing(sdp));
>
> /* At this point, we're through modifying the disk */
> --
> 2.39.2
thanks for this fix, I've merged it.
Andreas
prev parent reply other threads:[~2023-10-30 22:38 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-29 21:10 [PATCH] fs/gfs2: Fix slab-use-after-free in gfs2_qd_dealloc Juntong Deng
2023-10-30 22:38 ` Andreas Gruenbacher [this message]
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