diff --git a/sys/dev/raid/ciss/ciss.c b/sys/dev/raid/ciss/ciss.c
--- a/sys/dev/raid/ciss/ciss.c
+++ b/sys/dev/raid/ciss/ciss.c
@@ -1550,6 +1550,12 @@
 	 */
 	bus = CISS_EXTRA_BUS2(ea) - 1;
 	target = CISS_EXTRA_TARGET2(ea);
+	if (bus < 0 || bus >= sc->ciss_max_physical_bus ||
+	    target >= CISS_MAX_PHYSTGT) {
+		ciss_printf(sc, "physical device %d has out-of-range "
+			    "address bus %d target %d\n", i, bus, target);
+		continue;
+	}
 	sc->ciss_physical[bus][target].cp_address = cll->lun[i];
 	sc->ciss_physical[bus][target].cp_online = 1;
     }