[GDK] patch - avoid integer overflow when allocating a large block of memory

[Vlad Orlov]

[Impact]

Due to a logic error, an attempt to allocate a large block of memory fails in gdk_cairo_set_source_pixbuf, leading to a crash of the app that called it, for example, eom [1].

This issue had been fixed [2] in GTK+3, but GTK+2 apps that use the mentioned function still crash when trying to allocate a lot of memory. An example of such app is eom (Eye of MATE), an image viewer, which crashes when trying to load a large image.

I propose fixing it in current Ubuntu releases with the patch which fixes the crash.
The debdiffs are in the attachments in the comments below.

[Test Case]

Steps to reproduce:

1. Have a 64-bit installation of Ubuntu.
2. Install eom if it isn't installed.
3. Download the archive from the attachment of this post and unpack it. (Firefox doesn't allow me to upload image as is - tries to make thumbnail of it right in the file open dialog, then crashes.)
4. Open the unpacked image (27000_27000_1437947845.png) in eom.
5. eom crashes. The full backtrace is at [3].

You'll also see an error message: "failed to allocate 18446744072330584320 bytes". This huge number appears due to overflow during multiplication of two 32-bit signed integers. In the patch, this error is avoided by using a different memory allocation function.

[Regression Potential]

After several months of testing the patch in Debian Jessie, Debian Testing and Ubuntu 14.04, I haven't noticed any regressions.

[1] https://github.com/mate-desktop/eom/issues/93
[2] https://git.gnome.org/browse/gtk+/commit?id=894b1ae76a32720f4bb3d39cf460402e3ce331d6
[3] https://github.com/mate-desktop/eom/issues/93#issuecomment-141035799

[Ubuntu Foundations Team Bug Bot (crichton)]

The attachment "debdiff with the fix for Precise" seems to be a debdiff. The ubuntu-sponsors team has been subscribed to the bug report so that they can review and hopefully sponsor the debdiff. If the attachment isn't a patch, please remove the "patch" flag from the attachment, remove the "patch" tag, and if you are member of the ~ubuntu-sponsors, unsubscribe the team.

[This is an automated message performed by a Launchpad user owned by ~brian-murray, for any issue please contact him.]

[Sebastien Bacher (seb128)]

Thank you for your work. I've sponsored the xenial update (with a modified changelog, we don't have designed maintainers/NMUs in Ubuntu, also I tweaked the version number to not be .1 and listed the bug reference).

Once the update gets some testing in xenial we can look at the SRUs

Note that it would be nice to suggest to upstream that they backport the change to gtk-2-24 since they still roll updates to gtk2 sometimes and it could benefit users of other distros that way

[Seth Arnold (seth-arnold)]

Do you know if this issue has a CVE assigned yet? I didn't see one in the linked bug reports but those references may not have migrated to those sources yet.

Thanks

[Seth Arnold (seth-arnold)]

I've requested CVEs here http://www.openwall.com/lists/oss-security/2016/02/10/2

It appears this flaw was copy-pasted to a lot of programs.

Thanks

[Launchpad Janitor (janitor)]

This bug was fixed in the package gtk+2.0 - 2.24.29-1ubuntu2

---------------
gtk+2.0 (2.24.29-1ubuntu2) xenial; urgency=medium

  * gdkcairo-Avoid-integer-overflow.patch: new patch. Cherry-pick upstream
    commit from GTK+3 to avoid integer overflow when allocating a large block
    of memory in gdk_cairo_set_source_pixbuf. (lp: #1540811)

 -- Vlad Orlov <email address hidden> Tue, 02 Feb 2016 10:52:16 +0300

[Marc Deslauriers (mdeslaur)]

Since this is a security update, I'll sponsor these as security updates, and not as SRUs.

[Launchpad Janitor (janitor)]

This bug was fixed in the package gtk+2.0 - 2.24.10-0ubuntu6.3

---------------
gtk+2.0 (2.24.10-0ubuntu6.3) precise-security; urgency=low

  * gdkcairo-Avoid-integer-overflow.patch: new patch. Cherry-pick upstream
    commit from GTK+3 to avoid integer overflow when allocating a large block
    of memory in gdk_cairo_set_source_pixbuf. (LP: #1540811)
    - CVE-2013-7447

 -- Vlad Orlov <email address hidden> Tue, 22 Sep 2015 09:51:11 +0300

[Launchpad Janitor (janitor)]

This bug was fixed in the package gtk+2.0 - 2.24.23-0ubuntu1.4

---------------
gtk+2.0 (2.24.23-0ubuntu1.4) trusty-security; urgency=medium

  * gdkcairo-Avoid-integer-overflow.patch: new patch. Cherry-pick upstream
    commit from GTK+3 to avoid integer overflow when allocating a large block
    of memory in gdk_cairo_set_source_pixbuf. (LP: #1540811)
    - CVE-2013-7447

 -- Vlad Orlov <email address hidden> Tue, 22 Sep 2015 11:09:21 +0300

[Launchpad Janitor (janitor)]

This bug was fixed in the package gtk+3.0 - 3.4.2-0ubuntu0.9

---------------
gtk+3.0 (3.4.2-0ubuntu0.9) precise-security; urgency=medium

  * SECURITY UPDATE: integer overflow via large sized image (LP: #1540811)
    - debian/patches/CVE-2013-7447.patch: use g_malloc_n in
      gdk_cairo_set_source_pixbuf in gdk/gdkcairo.c.
    - CVE-2013-7447

 -- Marc Deslauriers <email address hidden> Fri, 12 Feb 2016 08:37:18 -0500

[Launchpad Janitor (janitor)]

This bug was fixed in the package gtk+2.0 - 2.24.28-1ubuntu1.1

---------------
gtk+2.0 (2.24.28-1ubuntu1.1) wily-security; urgency=medium

  * gdkcairo-Avoid-integer-overflow.patch: new patch. Cherry-pick upstream
    commit from GTK+3 to avoid integer overflow when allocating a large block
    of memory in gdk_cairo_set_source_pixbuf. (LP: #1540811)
    - CVE-2013-7447

 -- Vlad Orlov <email address hidden> Tue, 22 Sep 2015 13:27:04 +0300

[Vlad Orlov (monsta)]

Thank you guys!
Hope someone from Debian maintainers will take care of it as well...