[FFmpeg-cvslog] avformat/utils: Fix memleaks

[Andreas Rheinhardt]

ffmpeg | branch: release/4.2 | Andreas Rheinhardt <andreas.rheinhardt at gmail.com> | Tue Sep 24 18:31:44 2019 +0200| [f2117e1e9c5c87e794d6dff872d48026cf24db2f] | committer: Andreas Rheinhardt

avformat/utils: Fix memleaks

ff_read_packet had potential memleaks:
1. If av_packet_make_refcounted fails, it means that the packet is not
refcounted, but it could nevertheless carry side data and therefore
needs to be unreferenced.
2. If putting a packet on a packet list fails, it wasn't unreferenced.

Furthermore, read_frame_internal leaked a packet's (side) data if a
context update was required and failed.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at gmail.com>
Signed-off-by: James Almer <jamrial at gmail.com>
(cherry picked from commit 66d5e43b9909804511a3e1fb65f6f0bbb0264eb3)

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=f2117e1e9c5c87e794d6dff872d48026cf24db2f
---

 libavformat/utils.c | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/libavformat/utils.c b/libavformat/utils.c
index c2a5e5f581..73cdb3383c 100644
--- a/libavformat/utils.c
+++ b/libavformat/utils.c
@@ -878,8 +878,10 @@ int ff_read_packet(AVFormatContext *s, AVPacket *pkt)
         }
 
         err = av_packet_make_refcounted(pkt);
-        if (err < 0)
+        if (err < 0) {
+            av_packet_unref(pkt);
             return err;
+        }
 
         if ((s->flags & AVFMT_FLAG_DISCARD_CORRUPT) &&
             (pkt->flags & AV_PKT_FLAG_CORRUPT)) {
@@ -922,8 +924,10 @@ int ff_read_packet(AVFormatContext *s, AVPacket *pkt)
         err = ff_packet_list_put(&s->internal->raw_packet_buffer,
                                  &s->internal->raw_packet_buffer_end,
                                  pkt, 0);
-        if (err)
+        if (err < 0) {
+            av_packet_unref(pkt);
             return err;
+        }
         s->internal->raw_packet_buffer_remaining_size -= pkt->size;
 
         if ((err = probe_codec(s, st, pkt)) < 0)
@@ -1616,15 +1620,19 @@ static int read_frame_internal(AVFormatContext *s, AVPacket *pkt)
             }
 
             ret = avcodec_parameters_to_context(st->internal->avctx, st->codecpar);
-            if (ret < 0)
+            if (ret < 0) {
+                av_packet_unref(&cur_pkt);
                 return ret;
+            }
 
 #if FF_API_LAVF_AVCTX
 FF_DISABLE_DEPRECATION_WARNINGS
             /* update deprecated public codec context */
             ret = avcodec_parameters_to_context(st->codec, st->codecpar);
-            if (ret < 0)
+            if (ret < 0) {
+                av_packet_unref(&cur_pkt);
                 return ret;
+            }
 FF_ENABLE_DEPRECATION_WARNINGS
 #endif