Index: head/sys/geom/geom_dev.c
===================================================================
--- head/sys/geom/geom_dev.c
+++ head/sys/geom/geom_dev.c
@@ -346,9 +346,15 @@
 	cp->private = sc;
 	cp->flags |= G_CF_DIRECT_SEND | G_CF_DIRECT_RECEIVE;
 	error = g_attach(cp, pp);
-	KASSERT(error == 0 || error == ENXIO,
-	    ("g_dev_taste(%s) failed to g_attach, err=%d", pp->name, error));
-
+	if (error != 0) {
+		printf("%s: g_dev_taste(%s) failed to g_attach, error=%d\n",
+		    __func__, pp->name, error);
+		g_destroy_consumer(cp);
+		g_destroy_geom(gp);
+		mtx_destroy(&sc->sc_mtx);
+		g_free(sc);
+		return (NULL);
+	}
 	make_dev_args_init(&args);
 	args.mda_flags = MAKEDEV_CHECKNAME | MAKEDEV_WAITOK;
 	args.mda_devsw = &g_dev_cdevsw;
Index: head/sys/geom/uzip/g_uzip.c
===================================================================
--- head/sys/geom/uzip/g_uzip.c
+++ head/sys/geom/uzip/g_uzip.c
@@ -707,11 +707,11 @@
 	gp = g_new_geomf(mp, GUZ_DEV_NAME("%s"), pp->name);
 	cp = g_new_consumer(gp);
 	error = g_attach(cp, pp);
-	if (error == 0)
-		error = g_access(cp, 1, 0, 0);
-	if (error) {
+	if (error != 0)
+		goto e0;
+	error = g_access(cp, 1, 0, 0);
+	if (error)
 		goto e1;
-	}
 	g_topology_unlock();
 
 	/*
@@ -942,6 +942,7 @@
 	g_access(cp, -1, 0, 0);
 e1:
 	g_detach(cp);
+e0:
 	g_destroy_consumer(cp);
 	g_destroy_geom(gp);