diff --git a/sys/netgraph7/ng_fec.c b/sys/netgraph7/ng_fec.c
--- a/sys/netgraph7/ng_fec.c
+++ b/sys/netgraph7/ng_fec.c
@@ -539,6 +539,7 @@
 	sdl.sdl_index = ifp->if_index;
 
 	if (set) {
+		IF_ADDR_LOCK(trifp);
 		TAILQ_FOREACH(ifma, &trifp->if_multiaddrs, ifma_link) {
 			if (ifma->ifma_addr->sa_family != AF_LINK)
 				continue;