avformat/asfdec: Check the av_get_packet() return value

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavformat/asfdec.c

@@ -791,12 +791,17 @@ static int asf_read_header(AVFormatContext *s)
             if (!s->keylen) {
                 if (!ff_guidcmp(&g, &ff_asf_content_encryption)) {
                     unsigned int len;
+                    int ret;
                     AVPacket pkt;
                     av_log(s, AV_LOG_WARNING,
                            "DRM protected stream detected, decoding will likely fail!\n");
                     len= avio_rl32(pb);
                     av_log(s, AV_LOG_DEBUG, "Secret data:\n");
-                    av_get_packet(pb, &pkt, len); av_hex_dump_log(s, AV_LOG_DEBUG, pkt.data, pkt.size); av_free_packet(&pkt);
+
+                    if ((ret = av_get_packet(pb, &pkt, len)) < 0)
+                        return ret;
+                    av_hex_dump_log(s, AV_LOG_DEBUG, pkt.data, pkt.size);
+                    av_free_packet(&pkt);
                     len= avio_rl32(pb);
                     get_tag(s, "ASF_Protection_Type", -1, len, 32);
                     len= avio_rl32(pb);