diff --git a/sys/dev/raid/amr/amr.c b/sys/dev/raid/amr/amr.c
--- a/sys/dev/raid/amr/amr.c
+++ b/sys/dev/raid/amr/amr.c
@@ -831,6 +831,8 @@
 	/* copy cdb */
         len = au_cmd[2];
 	_ap->ap_cdb_length = len;
+	if (len > AMR_MAX_CDB_LEN)
+	    len = AMR_MAX_CDB_LEN;
 	bcopy(au_cmd + 3, _ap->ap_cdb, len);
 
 	/* build passthrough */