[FFmpeg-cvslog] r19973 - trunk/libavcodec/utils.c

[Reimar Döffinger]

On Wed, Sep 30, 2009 at 11:09:36PM -0700, Baptiste Coudurier wrote:
> On 9/22/09 3:44 PM, michael wrote:
> > Author: michael
> > Date: Wed Sep 23 00:44:56 2009
> > New Revision: 19973
> >
> > Log:
> > Check codec_id and codec_type in avcodec_open(), based on 43_codec_type_mismatch.patch from chrome
> > This is said to be able to lead to a stack based buffer overflow.
> >
> > Modified:
> >     trunk/libavcodec/utils.c
> >
> > Modified: trunk/libavcodec/utils.c
> > ==============================================================================
> > --- trunk/libavcodec/utils.c	Tue Sep 22 22:38:03 2009	(r19972)
> > +++ trunk/libavcodec/utils.c	Wed Sep 23 00:44:56 2009	(r19973)
> > @@ -481,7 +481,10 @@ int attribute_align_arg avcodec_open(AVC
> >       }
> >
> >       avctx->codec = codec;
> > -    avctx->codec_id = codec->id;
> > +    if(avctx->codec_id != codec->id || avctx->codec_type != codec->type){
> > +        av_log(avctx, AV_LOG_ERROR, "codec type or id mismatches\n");
> > +        goto end;
> > +    }
> >       avctx->frame_number = 0;
> >       if(avctx->codec->init){
> >           ret = avctx->codec->init(avctx);
> 
> It seems that quite some users are complaining about this change.
> What do we do ?

Is there any issue with doing
if (avctx->codec_id == CODEC_ID_UNKNOWN && avctx->codec_type == CODEC_TYPE_UNKNOWN)
{
    avctx->codec_id = codec->id;
    avctx->codec_type = codec->type;
}
?