[FFmpeg-devel] [PATCH] avformat/demux: Fix segfault due to avcodec_open2 failure (v2)

[Pavel Koshevoy]

pushed in commit 59a6660625675c8343f3de858b93c8294f05bb52


On Tue, Jun 24, 2025 at 5:19 PM Pavel Koshevoy <pkoshevoy at gmail.com> wrote:

> If I don't hear any objections in the next 72 hours I will apply this at
> that time, or later if I forget.
>
> Pavel.
>
>
> On Mon, Jun 23, 2025 at 2:37 PM Pavel Koshevoy <pkoshevoy at gmail.com>
> wrote:
>
>> ping ... as this is a segfault fix for `ffplay/ffprobe -i 1_poc.mp4` I
>> think it deserves some review/approval priority.
>>
>> On Mon, Jun 9, 2025 at 9:45 PM Pavel Koshevoy <pkoshevoy at gmail.com>
>> wrote:
>>
>>> Fixes 'ffprobe 1_poc.mp4' segfault introduced with
>>> commit 0021484d05f9b0f032fa319399de6e24eea0c04f
>>>
>>> codec_close should not assume that the codec_id did not change.
>>> ---
>>>  libavformat/demux.c | 8 +++++++-
>>>  1 file changed, 7 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/libavformat/demux.c b/libavformat/demux.c
>>> index ecd4f40da9..3749ab67a3 100644
>>> --- a/libavformat/demux.c
>>> +++ b/libavformat/demux.c
>>> @@ -1292,9 +1292,15 @@ static int codec_close(FFStream *sti)
>>>  {
>>>      AVCodecContext *avctx_new = NULL;
>>>      AVCodecParameters *par_tmp = NULL;
>>> +    const AVCodec *new_codec = NULL;
>>>      int ret;
>>>
>>> -    avctx_new = avcodec_alloc_context3(sti->avctx->codec);
>>> +    new_codec =
>>> +      (sti->avctx->codec_id != sti->pub.codecpar->codec_id) ?
>>> +      avcodec_find_decoder(sti->pub.codecpar->codec_id) :
>>> +      sti->avctx->codec;
>>> +
>>> +    avctx_new = avcodec_alloc_context3(new_codec);
>>>      if (!avctx_new) {
>>>          ret = AVERROR(ENOMEM);
>>>          goto fail;
>>> --
>>> 2.43.0
>>>
>>>