From d0ed3f78b82e2e9a4e39451b7559804f19697533 Mon Sep 17 00:00:00 2001
From: Aaron Conole <aconole@redhat.com>
Date: Wed, 31 Jul 2019 16:03:09 -0400
Subject: [PATCH] lldp_util: allow for null ifa_addr element

The call to getifaddrs assumes that ifa_addr is always a valid pointer, but
getifaddrs is allowed to return a NULL value in that field.  Check that the
value is valid before attempting to access.

Signed-off-by: Aaron Conole <aconole@redhat.com>
---
 lldp_util.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/lldp_util.c b/lldp_util.c
index 32df768..c43abbf 100644
--- a/lldp_util.c
+++ b/lldp_util.c
@@ -1055,9 +1055,11 @@ int get_saddr6(const char *ifname, struct sockaddr_in6 *saddr)
 
 	rc = getifaddrs(&ifaddr);
 	if (rc == 0) {
+		rc = -1;
 		for (ifa = ifaddr; ifa != NULL; ifa = ifa->ifa_next) {
-			if ((ifa->ifa_addr->sa_family == AF_INET6) &&
-			    (strncmp(ifa->ifa_name, ifname, IFNAMSIZ) == 0)) {
+			if (strncmp(ifa->ifa_name, ifname, IFNAMSIZ))
+				continue;
+			if (ifa->ifa_addr && (ifa->ifa_addr->sa_family == AF_INET6)) {
 				memcpy(saddr, ifa->ifa_addr, sizeof(*saddr));
 				rc = 0;
 				break;
-- 
2.21.0