[FFmpeg-devel] [PATCH 1/6] avformat/isom: Uninit layout in ff_mp4_read_dec_config_descr()

[James Almer]

On 4/2/2024 7:22 PM, Marton Balint wrote:
> 
> 
> On Mon, 1 Apr 2024, James Almer wrote:
> 
>> On 4/1/2024 8:40 PM, Michael Niedermayer wrote:
>>>  On Mon, Apr 01, 2024 at 06:33:22PM -0300, James Almer wrote:
>>>>  On 4/1/2024 5:56 PM, Michael Niedermayer wrote:
>>>>> Fixes:  memleak
>>>>> Fixes:  
>>>>> 67442/clusterfuzz-testcase-minimized-ffmpeg_dem_CAF_fuzzer-5068813261406208
>>>>>
>>>>>  Found-by: continuous fuzzing process
>>>>>  https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
>>>>>  Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
>>>>>  ---
>>>>>     libavformat/isom.c | 1 +
>>>>>     1 file changed, 1 insertion(+)
>>>>>
>>>>>  diff --git a/libavformat/isom.c b/libavformat/isom.c
>>>>>  index 9fbccd4437f..c5930bd4d87 100644
>>>>>  --- a/libavformat/isom.c
>>>>>  +++ b/libavformat/isom.c
>>>>>  @@ -359,6 +359,7 @@ int ff_mp4_read_dec_config_descr(AVFormatContext
>>>>>  *fc, AVStream *st, AVIOContext
>>>>>                                                     
>>>>> st->codecpar->extradata_size,
>>>>>                 1, fc);
>>>>>                 if (ret < 0)
>>>>>                     return ret;
>>>>>  +            av_channel_layout_uninit(&st->codecpar->ch_layout);
>>>>>                 st->codecpar->ch_layout.order = 
>>>>> AV_CHANNEL_ORDER_UNSPEC;
>>>>
>>>>  Not strictly related to this fix, but should we really drop the layout
>>>>  here
>>>>  by forcing unspec? We're also not even bothering to check if 
>>>> cfg.channels
>>>>  matches st->codecpar->ch_layout.nb_channels.
>>>
>>>  I was wondering the same.
>>>  I was hoping someone would know the specs well enouh to just say 
>>> straight
>>>  "this and that isnt legal together error out if thats true"
>>
>> Maybe Marton knows, since he's been working on this code.
> 
> I don't really know for sure. But it would make sense to me to only drop 
> the layout if the channel count is different from what we already know.

Ok, just did that, and also applied Michael's memleak fix. Thanks.