Index: if_tun.c
===================================================================
RCS file: /cvs/src/sys/net/if_tun.c,v
retrieving revision 1.212
diff -u -p -r1.212 if_tun.c
--- if_tun.c	25 Jan 2020 06:31:32 -0000	1.212
+++ if_tun.c	25 Jan 2020 10:30:47 -0000
@@ -300,6 +300,9 @@ tun_clone_destroy(struct ifnet *ifp)
 		KASSERT(sc->sc_dev == 0);
 	}
 	tun_wakeup(sc);
+
+	SMR_LIST_REMOVE_LOCKED(sc, sc_entry);
+	smr_barrier();
 	refcnt_finalize(&sc->sc_refs, "tundtor");
 
 	s = splhigh();
@@ -315,8 +318,6 @@ tun_clone_destroy(struct ifnet *ifp)
 	if_detach(ifp);
 	sigio_free(&sc->sc_sigio);
 
-	SMR_LIST_REMOVE_LOCKED(sc, sc_entry);
-	smr_barrier();
 	free(sc, M_DEVBUF, sizeof *sc);
 	return (0);
 }