diff --git a/fs/jfs/jfs_dmap.c b/fs/jfs/jfs_dmap.c
index cb3cda1390ad..8dba15c83a49 100644
--- a/fs/jfs/jfs_dmap.c
+++ b/fs/jfs/jfs_dmap.c
@@ -2142,6 +2142,11 @@ static void dbAllocBits(struct bmap * bmp, struct dmap * dp, s64 blkno,
 	int size;
 	s8 *leaf;
 
+	if(blkno >= le64_to_cpu(bmp->db_mapsize)) {
+		jfs_error(bmp->db_ipbmap->i_sb, "Allocation request out of bounds\n");
+		return;
+	}
+
 	/* pick up a pointer to the leaves of the dmap tree */
 	leaf = dp->tree.stree + LEAFIND;