diff --git a/fs/jfs/jfs_dmap.c b/fs/jfs/jfs_dmap.c
index 11c77757ead9..d55f0dd8d754 100644
--- a/fs/jfs/jfs_dmap.c
+++ b/fs/jfs/jfs_dmap.c
@@ -2871,6 +2871,9 @@ static void dbAdjTree(dmtree_t * tp, int leafno, int newval)
 	/* is the current value the same as the old value ?  if so,
 	 * there is nothing to do.
 	 */
+	if (WARN_ON_ONCE(lp >= CTLTREESIZE))
+		return;
+
 	if (tp->dmt_stree[lp] == newval)
 		return;