[FFmpeg-devel] [PATCH 2/2] avcodec/vp3: Check that theora is theora

[Reimar Döffinger]

On 24.07.2019, at 14:37, Michael Niedermayer <michael at niedermayer.cc> wrote:

> On Mon, Jul 22, 2019 at 07:07:57AM +0200, Reimar Döffinger wrote:
>> 
>> 
>> On 22.07.2019, at 01:25, Michael Niedermayer <michael at niedermayer.cc> wrote:
>> 
>>> Fixes: Timeout (2min -> 100ms)
>>> Fixes: 15366/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_THEORA_fuzzer-5737849938247680
>>> 
>>> Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
>>> Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
>>> ---
>>> libavcodec/vp3.c | 2 ++
>>> 1 file changed, 2 insertions(+)
>>> 
>>> diff --git a/libavcodec/vp3.c b/libavcodec/vp3.c
>>> index a6f759ebf5..8a165c1275 100644
>>> --- a/libavcodec/vp3.c
>>> +++ b/libavcodec/vp3.c
>>> @@ -2957,6 +2957,8 @@ static int theora_decode_header(AVCodecContext *avctx, GetBitContext *gb)
>>>    s->theora_header = 0;
>>>    s->theora = get_bits_long(gb, 24);
>>>    av_log(avctx, AV_LOG_DEBUG, "Theora bitstream version %X\n", s->theora);
>>> +    if (!s->theora)
>>> +        return AVERROR_INVALIDDATA;
>> 
>> That seems rather strict, a 1-bit error in this field and we don't even try?
>> Maybe set to 1 instead with a request for sample?
> 
> ok, will post a new patch

Thanks. Sorry if it was maybe a bit nitpicky comment, but seemed like doing it a but nicer might be worth the effort.