[FFmpeg-devel] [PATCH 1/3] avformat/mov: Check sample_sizes before using it

[James Almer]

On 7/26/2024 7:11 PM, James Almer wrote:
> On 7/26/2024 6:08 PM, Michael Niedermayer wrote:
>> Fixes: NULL pointer dereference
>> Fixes: 
>> 70569/clusterfuzz-testcase-minimized-ffmpeg_dem_MOV_fuzzer-5247918563459072
>>
>> 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/mov.c | 4 ++++
>>   1 file changed, 4 insertions(+)
>>
>> diff --git a/libavformat/mov.c b/libavformat/mov.c
>> index b74e43e2140..63db7d59a58 100644
>> --- a/libavformat/mov.c
>> +++ b/libavformat/mov.c
>> @@ -10060,6 +10060,10 @@ static int mov_read_header(AVFormatContext *s)
>>               st = item->st;
>>               sc = st->priv_data;
>> +
>> +            if (!sc->sample_sizes || !sc->sample_count)
>> +                return AVERROR_INVALIDDATA;
> 
> Deja vu. Didn't you send something like this before?
> 
> Also, can i get the sample? As with other issues, we shouldn't reach 

No, it was me: 
https://ffmpeg.org//pipermail/ffmpeg-devel/2024-June/330391.html

Still, i want to check the sample because i'm not sure how this code is 
reached like this.

> this point if these were not allocated.
> 
>> +
>>               st->codecpar->width  = item->width;
>>               st->codecpar->height = item->height;