The specification says that the ifa_addr field of struct ifaddrs may be NULL, and in Barrier Breaker, this does actually occur...
@@ -266,7 +266,7 @@ static void update_interface(void) {
memset(&G.iface.ifaddr, 0, sizeof(G.iface.ifaddr));
for (addr = addrs; addr; addr = addr->ifa_next) {
- if (addr->ifa_addr->sa_family != AF_INET6)
+ if (!addr->ifa_addr || addr->ifa_addr->sa_family != AF_INET6)
continue;
const struct sockaddr_in6 *in6 = (const struct sockaddr_in6 *)addr->ifa_addr;