From: Darrick J. Wong <darrick.wong@oracle.com>
Date: Wed, 25 Oct 2017 23:59:43 +0000 (-0700)
Subject: xfs: validate sb_logsunit is a multiple of the fs blocksize
X-Git-Tag: v4.14.178~35
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=a63c07ef001fab45ef713fc7c9046bda0720b6c1;p=thirdparty%2Fkernel%2Fstable.git

xfs: validate sb_logsunit is a multiple of the fs blocksize

commit 9c92ee208b1faa0ef2cc899b85fd0607b6fac7fe upstream.

Make sure the log stripe unit is sane before proceeding with mounting.
AFAICT this means that logsunit has to be 0, 1, or a multiple of the fs
block size.  Found this by setting the LSB of logsunit in xfs/350 and
watching the system crash as soon as we try to write to the log.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Suraj Jitindar Singh <surajjs@amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
index 4e768e606998a..360e32220f93d 100644
--- a/fs/xfs/xfs_log.c
+++ b/fs/xfs/xfs_log.c
@@ -608,6 +608,7 @@ xfs_log_mount(
 	xfs_daddr_t	blk_offset,
 	int		num_bblks)
 {
+	bool		fatal = xfs_sb_version_hascrc(&mp->m_sb);
 	int		error = 0;
 	int		min_logfsbs;
 
@@ -659,9 +660,20 @@ xfs_log_mount(
 			 XFS_FSB_TO_B(mp, mp->m_sb.sb_logblocks),
 			 XFS_MAX_LOG_BYTES);
 		error = -EINVAL;
+	} else if (mp->m_sb.sb_logsunit > 1 &&
+		   mp->m_sb.sb_logsunit % mp->m_sb.sb_blocksize) {
+		xfs_warn(mp,
+		"log stripe unit %u bytes must be a multiple of block size",
+			 mp->m_sb.sb_logsunit);
+		error = -EINVAL;
+		fatal = true;
 	}
 	if (error) {
-		if (xfs_sb_version_hascrc(&mp->m_sb)) {
+		/*
+		 * Log check errors are always fatal on v5; or whenever bad
+		 * metadata leads to a crash.
+		 */
+		if (fatal) {
 			xfs_crit(mp, "AAIEEE! Log failed size checks. Abort!");
 			ASSERT(0);
 			goto out_free_log;