[FFmpeg-devel] [PATCH v2] avformat/mux: Fix leaks of uncoded frames on errors
Andreas Rheinhardt
andreas.rheinhardt at gmail.com
Tue Mar 31 16:32:19 EEST 2020
If writing an uncoded frame fails at the preparatory steps of
av_[interleaved_]write_frame(), the frame would be either not freed
at all in case of av_write_frame() or would leak when the fake packet
would be unreferenced like an ordinary packet.
There is also a memleak when the output format is not suited for
writing uncoded frames as the documentation states that ownership of the
frame passes to av_[interleaved_]write_uncoded_frame(). Both of these
memleaks have been fixed.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at gmail.com>
---
V2: Now actually resetting the data of the AVPacket containing an
uncoded frame if said frame is freed.
libavformat/mux.c | 25 +++++++++++++++++++------
1 file changed, 19 insertions(+), 6 deletions(-)
diff --git a/libavformat/mux.c b/libavformat/mux.c
index 814d773b9d..dc8233a0d5 100644
--- a/libavformat/mux.c
+++ b/libavformat/mux.c
@@ -749,7 +749,7 @@ static int write_packet(AVFormatContext *s, AVPacket *pkt)
AVFrame *frame = (AVFrame *)pkt->data;
av_assert0(pkt->size == UNCODED_FRAME_PACKET_SIZE);
ret = s->oformat->write_uncoded_frame(s, pkt->stream_index, &frame, 0);
- av_frame_free(&frame);
+ av_frame_free((AVFrame **)&pkt->data);
} else {
ret = s->oformat->write_packet(s, pkt);
}
@@ -1239,7 +1239,11 @@ int av_interleaved_write_frame(AVFormatContext *s, AVPacket *pkt)
return ret;
}
fail:
- av_packet_unref(pkt);
+ // This is a deviation from the usual behaviour
+ // of av_interleaved_write_frame: We leave cleaning
+ // up uncoded frames to write_uncoded_frame_internal.
+ if (!(pkt->flags & AV_PKT_FLAG_UNCODED_FRAME))
+ av_packet_unref(pkt);
return ret;
}
@@ -1324,10 +1328,13 @@ static int write_uncoded_frame_internal(AVFormatContext *s, int stream_index,
AVFrame *frame, int interleaved)
{
AVPacket pkt, *pktp;
+ int ret;
av_assert0(s->oformat);
- if (!s->oformat->write_uncoded_frame)
- return AVERROR(ENOSYS);
+ if (!s->oformat->write_uncoded_frame) {
+ ret = AVERROR(ENOSYS);
+ goto free;
+ }
if (!frame) {
pktp = NULL;
@@ -1343,8 +1350,14 @@ static int write_uncoded_frame_internal(AVFormatContext *s, int stream_index,
pkt.flags |= AV_PKT_FLAG_UNCODED_FRAME;
}
- return interleaved ? av_interleaved_write_frame(s, pktp) :
- av_write_frame(s, pktp);
+ ret = interleaved ? av_interleaved_write_frame(s, pktp) :
+ av_write_frame(s, pktp);
+ if (ret < 0 && pktp) {
+ frame = (AVFrame*)pktp->data;
+ free:
+ av_frame_free(&frame);
+ }
+ return ret;
}
int av_write_uncoded_frame(AVFormatContext *s, int stream_index,
--
2.20.1
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