[PATCH 2/6] xfs: don't crash on corrupt /quotas dirent

Darrick J. Wong
2024-12-04T03:02:45Z

From: Darrick J. Wong <djwong@kernel.org>

If the /quotas dirent points to an inode but the inode isn't loadable
(and hence mkdir returns -EEXIST), don't crash, just bail out.

Cc: <stable@vger.kernel.org> # v6.13-rc1
Fixes: e80fbe1ad8eff7 ("xfs: use metadir for quota inodes")
Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
---
fs/xfs/xfs_qm.c | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/fs/xfs/xfs_qm.c b/fs/xfs/xfs_qm.c
index 69b70c3e999d72..dc8b1010d4d332 100644
--- a/fs/xfs/xfs_qm.c
+++ b/fs/xfs/xfs_qm.c
@@ -731,6 +731,13 @@ xfs_qm_create_metadir_qinos(
error = xfs_dqinode_mkdir_parent(mp, &qi->qi_dirip);
if (error && error != -EEXIST)
return error;
+ /*
+ * If the /quotas dirent points to an inode that isn't
+ * loadable, qi_dirip will be NULL but mkdir_parent will return
+ * -EEXIST. In this case the metadir is corrupt, so bail out.
+ */
+ if (XFS_IS_CORRUPT(mp, qi->qi_dirip == NULL))
+ return -EFSCORRUPTED;
}

if (XFS_IS_UQUOTA_ON(mp) && !qi->qi_uquotaip) {