[FFmpeg-devel] [PATCH] Checked get_bits.h functions to prevent overread

[Reimar Döffinger]

On Fri, Sep 09, 2011 at 09:46:34AM +0000, Carl Eugen Hoyos wrote:
> Laurent Aimar <fenrir <at> elivagar.org> writes:
> 
> > > > I have a list of crashes with their backtraces. A lot of the files used
> > > > comes from VLC and mplayer FTP and so will probably be easy to retreive.
> > > 
> > > > Is sending it to the ML is the right choice ?
> > > 
> > > What's wrong with opening a ticket as explained on
> > > http://ffmpeg.org/bugreports.html?
> > 
> >  It depends. I can create a unique ticket for the backtrace I have
> 
> That would be great! (or do you mean you could but it is too much effort?)
> 
> > but I
> > won't do it for each crash I found (it was from an automated fuzzing tool
> > and I have more than 400 crashes, of course some come from the same bug).
> 
> I am just trying to say that if a developer believes your patch is not 
> acceptable he has not much chance currently to fix the crashes individually.
> 
> You should make the 400 files available in some way, the best way is probably 
> the bug tracker.

One sample per codec at the very least would be highly advisable.
Just hacking the bitstream reader is unlikely to give really good
results, even in the cases where it does not only replace the crash by
an endless loop.
And past experience would indicate there are decoders that are trivial
to fix but nobody was aware they existed...