diff --git a/drivers/s390/block/scm_blk_cluster.c b/drivers/s390/block/scm_blk_cluster.c
index 09db45296eed2c87330399abbfecdbb2f9b44014..7497ddde2dd67a28ce2e042970bebda9b3e9da5b 100644
--- a/drivers/s390/block/scm_blk_cluster.c
+++ b/drivers/s390/block/scm_blk_cluster.c
@@ -92,7 +92,7 @@ bool scm_reserve_cluster(struct scm_request *scmrq)
 			add = 0;
 			continue;
 		}
-		for (pos = 0; pos <= iter->aob->request.msb_count; pos++) {
+		for (pos = 0; pos < iter->aob->request.msb_count; pos++) {
 			if (clusters_intersect(req, iter->request[pos]) &&
 			    (rq_data_dir(req) == WRITE ||
 			     rq_data_dir(iter->request[pos]) == WRITE)) {