--- sys/netinet6/ip6_output.c.orig
+++ sys/netinet6/ip6_output.c
@@ -1514,8 +1514,10 @@
 				error = soopt_mcopyin(sopt, m); /* XXX */
 				if (error != 0)
 					break;
+				INP_WLOCK(in6p);
 				error = ip6_pcbopts(&in6p->in6p_outputopts,
 						    m, so, sopt);
+				INP_WUNLOCK(in6p);
 				m_freem(m); /* XXX */
 				break;
 			}
@@ -2260,8 +2262,11 @@
 			printf("ip6_pcbopts: all specified options are cleared.\n");
 #endif
 		ip6_clearpktopts(opt, -1);
-	} else
-		opt = malloc(sizeof(*opt), M_IP6OPT, M_WAITOK);
+	} else {
+		opt = malloc(sizeof(*opt), M_IP6OPT, M_NOWAIT);
+		if (opt == NULL)
+			return (ENOMEM);
+	}
 	*pktopt = NULL;
 
 	if (!m || m->m_len == 0) {