[DVDnav-discuss] [MPlayer-dev-eng] libdvdread: seqfault and patch to fix it

[Dominik 'Rathann' Mierzejewski]

Hi,

On Sunday, 11 July 2010 at 00:35, Morten Sjøgren wrote:
> Hi,
> 
> I've found a seqfault in the libdvdread.
> 
> I found it in the libdvdread package used by kubuntu, which is from the
> http://git.debian-maintainers.org/?p=daniel/libdvdread.git but I'm pretty
> sure it's a problem with mplayers version too.
> 
> The seqfault happens in src/ifo_read.c on line 1353, function
> ifoFree_PTL_MAIT.
> 
> I've tracked it to an earlier point in the program in the function
> ifoRead_PTL_MAIT in the same file around line 1304.
> 
> The message "libdvdread: Unable to seak PTL_MAIT table." is triggered and
> the variable ptl_mait was freed but the pointer on ifofile->ptl_mait wasn't
> set to zero.
> This makes the function ifoFree_PTL_MAIT attempt to free the data, even
> though it has already been freed.

Thanks for the bug report and the analysis. Good work. Could you verify
that this happens with current libdvdread SVN
(svn://svn.mplayerhq.hu/dvdnav/trunk/libdvdread) as well?

> My patch which is attached to the email fixes the problem by simply setting
> ifofile->ptl_mait = 0.

Wouldn't it be more correct to set it to NULL instead?

> I've also written Daniel Baumann who seems to maintain the debian package,
> as I'm not sure who maintains the upstream for this.

Current upstream consists of some MPlayer developers and some other
interested people. We have a mailing list here:
https://lists.mplayerhq.hu/mailman/listinfo/dvdnav-discuss

Regards,
Dominik

-- 
MPlayer http://mplayerhq.hu | RPMFusion http://rpmfusion.org
There should be a science of discontent. People need hard times and
oppression to develop psychic muscles.
	-- from "Collected Sayings of Muad'Dib" by the Princess Irulan