[FFmpeg-devel] [PATCH 1/5] avformat/argo_brp: Check block align before use

[Zane van Iperen]

On 2/11/20 9:40 pm, Anton Khirnov wrote:
> 
> Quoting Michael Niedermayer (2020-10-30 22:52:02)
>> Fixes: division by 0
>> Fixes: 26667/clusterfuzz-testcase-minimized-ffmpeg_dem_ARGO_BRP_fuzzer-5645146928185344.fuzz
>>
>> 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/argo_brp.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/libavformat/argo_brp.c b/libavformat/argo_brp.c
>> index 48e0cd6aa4..7c679e944c 100644
>> --- a/libavformat/argo_brp.c
>> +++ b/libavformat/argo_brp.c
>> @@ -390,7 +390,7 @@ static int argo_brp_read_packet(AVFormatContext *s, AVPacket *pkt)
>>
>>           blk.size -= ASF_CHUNK_HEADER_SIZE;
>>
>> -        if (blk.size % st->codecpar->block_align != 0)
>> +        if (st->codecpar->block_align && blk.size % st->codecpar->block_align != 0)
> 
> Shouldn't block_align==0 also trigger an error?
> 

block_align should never be zero for adocm_argo (is always 17 or 34), so 
this looks like a validation error in ff_argo_asf_fill_stream(). I'll 
investigate.