[FFmpeg-devel] [PATCH] rmdec: validate block alignment

[Andreas Cadhalpun]

On 18.11.2016 02:44, Michael Niedermayer wrote:
> On Thu, Nov 17, 2016 at 10:52:30PM +0100, Andreas Cadhalpun wrote:
>> This fixes division by zero crashes.
>>
>> Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun at googlemail.com>
>> ---
>>  libavformat/rmdec.c | 4 ++++
>>  1 file changed, 4 insertions(+)
>>
>> diff --git a/libavformat/rmdec.c b/libavformat/rmdec.c
>> index d175862..4d56529 100644
>> --- a/libavformat/rmdec.c
>> +++ b/libavformat/rmdec.c
>> @@ -934,6 +934,10 @@ ff_rm_parse_packet (AVFormatContext *s, AVIOContext *pb,
>>  
>>               ast->sub_packet_cnt = 0;
>>               rm->audio_stream_num = st->index;
>> +            if (st->codecpar->block_align <= 0) {
>> +                av_log(s, AV_LOG_ERROR, "Invalid block alignment %d\n", st->codecpar->block_align);
>> +                return AVERROR_INVALIDDATA;
>> +            }
>>               rm->audio_pkt_cnt = h * w / st->codecpar->block_align;
> 
> indention looks odd

That's because the two lines above and the line below are indented one
space too much.

> also i think this is already checked in rm_read_audio_stream_info() is
> that check somehow broken ?

That check is fine, but the codecpar can be changed by the API user,
e.g. when forcing a particular codec_id.

Best regards,
Andreas