Index: sys/net/if_lagg.c
===================================================================
--- sys/net/if_lagg.c
+++ sys/net/if_lagg.c
@@ -679,6 +679,9 @@
 		return (EINVAL);
 	}
 
+	if (sc->sc_destroying == 1)
+		return (ENXIO);
+
 	/* Limit the maximal number of lagg ports */
 	if (sc->sc_count >= LAGG_MAX_PORTS)
 		return (ENOSPC);
@@ -1191,6 +1194,8 @@
 
 	bzero(&rpbuf, sizeof(rpbuf));
 
+	/* XXX: This can race with lagg_clone_destroy. */
+
 	switch (cmd) {
 	case SIOCGLAGG:
 		LAGG_XLOCK(sc);