[PATCH 3/3] xfs: sb_spino_align is not verified

[Dave Chinner <david@fromorbit.com>]

From: Dave Chinner <dchinner@redhat.com>

It's just read in from the superblock and used without doing any
validity checks at all on the value.

Fixes: fb4f2b4e5a82 ("xfs: add sparse inode chunk alignment superblock field")
Signed-off-by: Dave Chinner <dchinner@redhat.com>
---
 fs/xfs/libxfs/xfs_sb.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/fs/xfs/libxfs/xfs_sb.c b/fs/xfs/libxfs/xfs_sb.c
index d95409f3cba6..0d181bc140f0 100644
--- a/fs/xfs/libxfs/xfs_sb.c
+++ b/fs/xfs/libxfs/xfs_sb.c
@@ -398,6 +398,20 @@ xfs_validate_sb_common(
 					 sbp->sb_inoalignmt, align);
 				return -EINVAL;
 			}
+
+			if (!sbp->sb_spino_align ||
+			    sbp->sb_spino_align > sbp->sb_inoalignmt ||
+			    (sbp->sb_inoalignmt % sbp->sb_spino_align) != 0) {
+				xfs_warn(mp,
+				"Sparse inode alignment (%u) is invalid.",
+					sbp->sb_spino_align);
+				return -EINVAL;
+			}
+		} else if (sbp->sb_spino_align) {
+			xfs_warn(mp,
+				"Sparse inode alignment (%u) should be zero.",
+				sbp->sb_spino_align);
+			return -EINVAL;
 		}
 	} else if (sbp->sb_qflags & (XFS_PQUOTA_ENFD | XFS_GQUOTA_ENFD |
 				XFS_PQUOTA_CHKD | XFS_GQUOTA_CHKD)) {
-- 
2.45.2