--- a/sys/dev/raid/mps/mps.c
+++ b/sys/dev/raid/mps/mps.c
@@ mps_attach @@
 	if ((error = mps_get_iocfacts(sc, sc->facts)) != 0)
 		return (error);
 
+	if (sc->facts->IOCRequestFrameSize * 4 < sizeof(MPI2_CONFIG_REQUEST)) {
+		mps_printf(sc, "%s IOCRequestFrameSize %d too small\n", __func__,
+		    sc->facts->IOCRequestFrameSize);
+		return (EINVAL);
+	}
+
 	mps_print_iocfacts(sc, sc->facts);