Bug#711045: libapt-pkg4.12: double free or corruption with libbz2

[Michael Vogt <mvo@debian.org>]

On Tue, Jun 04, 2013 at 10:55:02AM +0200, Gregoire Menuel wrote:
> Package: libapt-pkg4.12
> Version: 0.9.7.8
> Severity: normal
> Tags: patch

Thanks for your bugreort and your patch.
 
> Dear Maintainer,
> 
> In some cases apt will crash yelding a double free or corruption error, I've
> encountered the bug with apt-cdrom add for exemple.
> 
> The attached patch seems to fix that bug.

I can reproduce this in a small test program. Patch is applied and
will be part of the next upload.

Thanks!
 Michael

> Regards,
> 
> Grégoire Menuel
> 
> 
> 
> -- System Information:
> Debian Release: 7.0
>   APT prefers stable-updates
>   APT policy: (500, 'stable-updates'), (500, 'stable')
> Architecture: amd64 (x86_64)
> 
> Kernel: Linux 3.2.0-4-amd64 (SMP w/8 CPU cores)
> Locale: LANG=fr_FR.utf8, LC_CTYPE=fr_FR.utf8 (charmap=UTF-8)
> Shell: /bin/sh linked to /bin/dash
> 
> Versions of packages libapt-pkg4.12 depends on:
> ii  libbz2-1.0         1.0.6-4
> ii  libc6              2.13-38
> ii  libgcc1            1:4.7.2-5
> ii  libstdc++6         4.7.2-5
> ii  multiarch-support  2.13-38
> ii  zlib1g             1:1.2.7.dfsg-13
> 
> libapt-pkg4.12 recommends no packages.
> 
> libapt-pkg4.12 suggests no packages.
> 
> -- no debconf information

> Index: apt-pkg/contrib/fileutl.cc
> ===================================================================
> --- apt-pkg/contrib/fileutl.cc	(révision 8604)
> +++ apt-pkg/contrib/fileutl.cc	(copie de travail)
> @@ -1424,8 +1424,10 @@
>  	 return _error->Error("Reopen is only implemented for read-only files!");
>        }
>  #ifdef HAVE_BZ2
> -      if (d->bz2 != NULL)
> -	 BZ2_bzclose(d->bz2);
> +     if (d->bz2 != NULL) {
> +	BZ2_bzclose(d->bz2);
> +	d->bz2 = NULL;
> +     }
>  #endif
>        if (iFd != -1)
>  	 close(iFd);