linux-ext4 - [PATCH] xfs: prohibit fstrim in norecovery mode

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Fri, 22 Mar 2019 17:37:20 -0700
From:   "Darrick J. Wong" <darrick.wong@...cle.com>
To:     xfs <linux-xfs@...r.kernel.org>
Cc:     fstests <fstests@...r.kernel.org>, Eryu Guan <guaneryu@...il.com>,
        linux-ext4 <linux-ext4@...r.kernel.org>
Subject: [PATCH] xfs: prohibit fstrim in norecovery mode

From: Darrick J. Wong <darrick.wong@...cle.com>

The xfs fstrim implementation uses the free space btrees to find free
space that can be discarded.  If we haven't recovered the log, the bnobt
will be stale and we absolutely *cannot* use stale metadata to zap the
underlying storage.

Signed-off-by: Darrick J. Wong <darrick.wong@...cle.com>
---
 fs/xfs/xfs_discard.c |    8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/fs/xfs/xfs_discard.c b/fs/xfs/xfs_discard.c
index 93f07edafd81..9ee2a7d02e70 100644
--- a/fs/xfs/xfs_discard.c
+++ b/fs/xfs/xfs_discard.c
@@ -161,6 +161,14 @@ xfs_ioc_trim(
 		return -EPERM;
 	if (!blk_queue_discard(q))
 		return -EOPNOTSUPP;
+
+	/*
+	 * We haven't recovered the log, so we cannot use our bnobt-guided
+	 * storage zapping commands.
+	 */
+	if (mp->m_flags & XFS_MOUNT_NORECOVERY)
+		return -EROFS;
+
 	if (copy_from_user(&range, urange, sizeof(range)))
 		return -EFAULT;