lavc/avpacket: Fix undefined behaviour, do not pass a null pointer to memcpy().

Fixes ticket #5128.

Gbp-Pq: Name CVE-2018-5766.patch

diff --git a/libavcodec/avpacket.c b/libavcodec/avpacket.c
index cad804798495efeb2de9535b9cf27e5ae6ce70f4..10ee1a439c359bc1a8ee2829bed5916ae56ceb7e 100644 (file)
--- a/libavcodec/avpacket.c
+++ b/libavcodec/avpacket.c
@@ -364,7 +364,8 @@ int av_packet_ref(AVPacket *dst, AVPacket *src)
         ret = packet_alloc(&dst->buf, src->size);
         if (ret < 0)
             goto fail;
-        memcpy(dst->buf->data, src->data, src->size);
+        if (src->size)
+            memcpy(dst->buf->data, src->data, src->size);
 
         dst->data = dst->buf->data;
     } else {