[FFmpeg-devel] [PATCH 1/3] avformat/cafdec: sanity check channels and bps

[Anton Khirnov]

Quoting Michael Niedermayer (2024-06-25 21:25:46)
> On Thu, Mar 28, 2024 at 12:27:02AM +0100, Michael Niedermayer wrote:
> > On Wed, Mar 27, 2024 at 08:39:17AM +0100, Anton Khirnov wrote:
> > > Quoting Michael Niedermayer (2024-03-23 00:08:16)
> > > > Fixes: Timeout
> > > > Fixes: 67044/clusterfuzz-testcase-minimized-ffmpeg_dem_CAF_fuzzer-5791144363491328
> > > > 
> > > > 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/cafdec.c | 5 +++++
> > > >  1 file changed, 5 insertions(+)
> > > > 
> > > > diff --git a/libavformat/cafdec.c b/libavformat/cafdec.c
> > > > index 426c56b9bd..334077efb5 100644
> > > > --- a/libavformat/cafdec.c
> > > > +++ b/libavformat/cafdec.c
> > > > @@ -33,6 +33,7 @@
> > > >  #include "isom.h"
> > > >  #include "mov_chan.h"
> > > >  #include "libavcodec/flac.h"
> > > > +#include "libavcodec/internal.h"
> > > >  #include "libavutil/intreadwrite.h"
> > > >  #include "libavutil/intfloat.h"
> > > >  #include "libavutil/dict.h"
> > > > @@ -87,6 +88,10 @@ static int read_desc_chunk(AVFormatContext *s)
> > > >      st->codecpar->ch_layout.nb_channels = avio_rb32(pb);
> > > >      st->codecpar->bits_per_coded_sample = avio_rb32(pb);
> > > >  
> > > > +    if (st->codecpar->ch_layout.nb_channels > FF_SANE_NB_CHANNELS ||
> > > 
> > > I dislike this.
> > 
> > I dislike it too
> 
> so what do we do about this ?

About what? What is the actual problem that needs addressed?

> any objections to apply this ?

yes, FF_SANE_NB_CHANNELS is a hack that should be removed, not spread

-- 
Anton Khirnov