avformat/udp: check for memory allocation failure when setting localaddr

Signed-off-by: jackarain <jack.wgm@gmail.com>
Signed-off-by: Marton Balint <cus@passwd.hu>

libavformat/udp.c

@@ -740,6 +740,10 @@ static int udp_open(URLContext *h, const char *uri, int flags)
         if (av_find_info_tag(buf, sizeof(buf), "localaddr", p)) {
             av_freep(&s->localaddr);
             s->localaddr = av_strdup(buf);
+            if (!s->localaddr) {
+                ret = AVERROR(ENOMEM);
+                goto fail;
+            }
         }
         if (av_find_info_tag(buf, sizeof(buf), "sources", p)) {
             if ((ret = ff_ip_parse_sources(h, buf, &s->filters)) < 0)