From: "Luís Henriques via Ocfs2-devel" <ocfs2-devel@oss.oracle.com>
To: Mark Fasheh <mark@fasheh.com>, Joel Becker <jlbec@evilplan.org>,
Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: stable@vger.kernel.org, linux-kernel@vger.kernel.org,
ocfs2-devel@oss.oracle.com
Subject: [Ocfs2-devel] [PATCH] ocfs2: fix use-after-free when unmounting read-only filesystem
Date: Mon, 22 May 2023 11:20:30 +0100 [thread overview]
Message-ID: <20230522102030.8986-1-lhenriques@suse.de> (raw)
It's trivial to trigger a use-after-free bug in the ocfs2 quotas code using
fstest generic/452. After mounting a filesystem as read-only, quotas are
suspended and ocfs2_mem_dqinfo is freed through ->ocfs2_local_free_info(). When
unmounting the filesystem, an UAF access to the oinfo will eventually cause a
crash.
Cc: <stable@vger.kernel.org>
Signed-off-by: Luís Henriques <lhenriques@suse.de>
---
fs/ocfs2/super.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
index 0b0e6a132101..988d1c076861 100644
--- a/fs/ocfs2/super.c
+++ b/fs/ocfs2/super.c
@@ -952,8 +952,10 @@ static void ocfs2_disable_quotas(struct ocfs2_super *osb)
for (type = 0; type < OCFS2_MAXQUOTAS; type++) {
if (!sb_has_quota_loaded(sb, type))
continue;
- oinfo = sb_dqinfo(sb, type)->dqi_priv;
- cancel_delayed_work_sync(&oinfo->dqi_sync_work);
+ if (!sb_has_quota_suspended(sb, type)) {
+ oinfo = sb_dqinfo(sb, type)->dqi_priv;
+ cancel_delayed_work_sync(&oinfo->dqi_sync_work);
+ }
inode = igrab(sb->s_dquot.files[type]);
/* Turn off quotas. This will remove all dquot structures from
* memory and so they will be automatically synced to global
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next reply other threads:[~2023-05-22 16:27 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-22 10:20 Luís Henriques via Ocfs2-devel [this message]
-- strict thread matches above, loose matches on Subject: below --
2023-05-22 10:21 [Ocfs2-devel] [PATCH] ocfs2: fix use-after-free when unmounting read-only filesystem Luís Henriques via Ocfs2-devel
2023-05-22 10:24 Luís Henriques via Ocfs2-devel
2023-05-22 10:25 Luís Henriques via Ocfs2-devel
2023-05-22 12:01 ` Joseph Qi via Ocfs2-devel
2023-05-22 12:23 ` Luís Henriques via Ocfs2-devel
2023-05-22 12:36 ` Heming Zhao via Ocfs2-devel
2023-05-22 13:22 ` Luís Henriques via Ocfs2-devel
2023-05-23 2:43 ` Joseph Qi via Ocfs2-devel
2023-05-23 2:41 ` Joseph Qi via Ocfs2-devel
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