1 files changed, 12 insertions, 0 deletions
diff --git a/fs/xfs/libxfs/xfs_sb.c b/fs/xfs/libxfs/xfs_sb.c
index f3835e923893..3d29f4a5242f 100644
--- a/fs/xfs/libxfs/xfs_sb.c
+++ b/fs/xfs/libxfs/xfs_sb.c
@@ -150,6 +150,18 @@ xfs_validate_sb_write(
 	struct xfs_mount	*mp,
 	struct xfs_sb		*sbp)
 {
+	/*
+	 * Carry out additional sb summary counter sanity checks when we write
+	 * the superblock.  We skip this in the read validator because there
+	 * could be newer superblocks in the log and if the values are garbage
+	 * we'll recalculate them at the end of log mount.
+	 */
+	if (sbp->sb_fdblocks > sbp->sb_dblocks ||
+	    sbp->sb_ifree > sbp->sb_icount) {
+		xfs_warn(mp, "SB summary counter sanity check failed");
+		return -EFSCORRUPTED;
+	}
+
 	if (XFS_SB_VERSION_NUM(sbp) != XFS_SB_VERSION_5)
 		return 0;