Bug 59825 - SIGSEGV: uninitialized variable "framebuffer" inside __glXDRIscreenProbe
Summary: SIGSEGV: uninitialized variable "framebuffer" inside __glXDRIscreenProbe
Alias: None
Product: xorg
Classification: Unclassified
Component: Server/Ext/GLX (show other bugs)
Version: git
Hardware: All All
: highest blocker
Assignee: Xorg Project Team
QA Contact: Xorg Project Team
Keywords: patch
Depends on:
Blocks: xserver-1.14
  Show dependency treegraph
Reported: 2013-01-24 21:45 UTC by Benjamin Robin
Modified: 2013-07-10 23:49 UTC (History)
5 users (show)

See Also:
i915 platform:
i915 features:

Add initialization of framebuffer.base (521 bytes, patch)
2013-01-24 22:37 UTC, Benjamin Robin
no flags Details | Splinter Review

Description Benjamin Robin 2013-01-24 21:45:43 UTC
The following variable "__DRIframebuffer framebuffer" is not initialized in glxdri.c:960

framebuffer.base shall be initialized to NULL, because in case of error (handle_error line 1140), framebuffer.base is checked... 

This bug trig a segmentation fault described in this back trace: http://pastebin.com/iJzw4edM.

For background information read the original bug report here : https://bugs.archlinux.org/task/33229
Comment 1 Benjamin Robin 2013-01-24 22:37:39 UTC
Created attachment 73618 [details] [review]
Add initialization of framebuffer.base
Comment 2 Ben Liblit 2013-06-07 19:13:50 UTC
I have seen the same problem under Fedora 19 beta.  It appears when running as a 32-bit VirtualBox guest.  I originally reported this as VirtualBox bug <https://www.virtualbox.org/ticket/11821>.  From there I was referred to Arch Linux bug <https://bugs.archlinux.org/task/33229>, which referred me here.

I have applied the fix suggested in comment #1.  It works.  The problem appeared every single time before, but vanishes completely with this fix in place.

See also <https://bugzilla.redhat.com/show_bug.cgi?id=972095> for my report of this as a Fedora bug, in which I suggest that the fix from comment #1 be applied to Fedora's X server builds.
Comment 3 Sérgio M. Basto 2013-07-08 14:10:51 UTC
Hi what the state of the patch , seems very easy, we need this urgently in Fedora 19 , 
This already marked with a critical bug .
This patch is already approved ? and push to upstream ? and maybe also is good idea push to stable branch .  

Comment 4 Benjamin Robin 2013-07-08 21:07:06 UTC
(In reply to comment #3)
> Hi what the state of the patch 
> This patch is already approved ? and push to upstream ? and maybe also is
> good idea push to stable branch .  

The patch was applied in "master" the 2013-03-18, but looks like nobody merged it in the stable branch "server-1.14-branch"

I bump the importance to the maximum...
Comment 5 Alan Coopersmith 2013-07-08 21:22:08 UTC
No one pays attention to the "importance" fields of the bugs in bugzilla.

If you want to nominate something to be backported to the stable branch
you would need to contact the maintainer of that stable branch - currently
Matt Dew for the 1.14 stable branch.

Marking this bug as fixed, since the patch was integrated into the Xorg
tree for the 1.15 release:
Comment 6 Peter Hutterer 2013-07-10 23:49:23 UTC
requested for 1.14 stable branch, should be in 1.14.3 if it all goes well

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