[FFmpeg-devel] [PATCH] avfilter/scale: fix CID 1457833

[Gyan]

On 16-01-2020 09:07 pm, Anton Khirnov wrote:
> Quoting Gyan Doshi (2020-01-16 13:59:47)
>> ---
>>   libavfilter/vf_scale.c | 6 ++----
>>   1 file changed, 2 insertions(+), 4 deletions(-)
>>
>> diff --git a/libavfilter/vf_scale.c b/libavfilter/vf_scale.c
>> index d46c767e70..70978345e8 100644
>> --- a/libavfilter/vf_scale.c
>> +++ b/libavfilter/vf_scale.c
>> @@ -498,10 +498,8 @@ static int config_props(AVFilterLink *outlink)
>>                                  scale->force_original_aspect_ratio,
>>                                  scale->force_divisible_by);
>>   
>> -    if (scale->w > INT_MAX ||
>> -        scale->h > INT_MAX ||
>> -        (scale->h * inlink->w) > INT_MAX ||
>> -        (scale->w * inlink->h) > INT_MAX)
>> +    if (((int64_t)scale->h * inlink->w) > INT_MAX ||
>> +        ((int64_t)scale->w * inlink->h) > INT_MAX)
> This only works when int is 32bit, which is not guaranteed to be true.
> The correct way to test it is something like
> if (scale->h > INT_MAX / inlink->w)

Makes sense. I took my cue from similar checks in other scale filters. 
Should convert those too.

Although I do wonder why this check exists at this time. All it results 
in is a log msg; any invalid values aren't adjusted. Should this be 
replaced with av_image_check_size2 or is there another reason for this 
check?

Gyan