Index: sys/netgraph/ng_socket.c
===================================================================
--- sys/netgraph/ng_socket.c
+++ sys/netgraph/ng_socket.c
@@ -1025,12 +1025,15 @@
 	addr->sg_data[addrlen] = '\0';
 
 	/* Try to tell the socket which hook it came in on. */
-	if (sbappendaddr(&so->so_rcv, (struct sockaddr *)addr, m, NULL) == 0) {
+	SOCKBUF_LOCK(&so->so_rcv);
+	if (sbappendaddr_locked(&so->so_rcv, (struct sockaddr *)addr, m,
+		NULL) == 0) {
+		SOCKBUF_UNLOCK(&so->so_rcv);
 		m_freem(m);
 		TRAP_ERROR;
 		return (ENOBUFS);
 	}
-	sorwakeup(so);
+	sorwakeup_locked(so);
 	return (0);
 }