Xorg crashed with SIGABRT in OsAbort()

[David]

This occurred immediately after logging out of a user section (only one user was logged in at the time). The screen went black and I was prompted to start a low-res session. This failed, so I restarted the machine. I received a kernel update 2-3 reboots before this happened (no Xorg, Nvidia or other graphicsy updates that I can recall).

ProblemType: Crash
DistroRelease: Ubuntu 14.10
Package: xserver-xorg-core 2:1.16.0-1ubuntu1.3
ProcVersionSignature: Ubuntu 3.16.0-31.43-generic 3.16.7-ckt5
Uname: Linux 3.16.0-31-generic x86_64
.tmp.unity.support.test.0:

ApportVersion: 2.14.7-0ubuntu8.2
Architecture: amd64
CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CompositorRunning: compiz
CompositorUnredirectDriverBlacklist: '(nouveau|Intel).*Mesa 8.0'
CompositorUnredirectFSW: true
Date: Thu Mar 12 21:42:51 2015
DistUpgraded: 2014-10-25 08:39:54,820 DEBUG enabling apt cron job
DistroCodename: utopic
DistroVariant: ubuntu
DkmsStatus:
 bbswitch, 0.7, 3.16.0-31-generic, x86_64: installed
 nvidia-331-updates, 331.113, 3.16.0-31-generic, x86_64: installed
 nvidia-331-updates-uvm, 331.113, 3.16.0-31-generic, x86_64: installed
 vboxhost, 4.3.24, 3.16.0-31-generic, x86_64: installed
ExecutablePath: /usr/bin/Xorg
ExtraDebuggingInterest: No
GraphicsCard:
 Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller [8086:0116] (rev 09) (prog-if 00 [VGA controller])
   Subsystem: Dell Device [1028:04b6]
 NVIDIA Corporation GF108M [GeForce GT 525M] [10de:0df5] (rev ff) (prog-if ff)
InstallationDate: Installed on 2014-04-24 (322 days ago)
InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Release amd64 (20140417)
MachineType: Dell Inc. Dell System XPS L502X
ProcCmdline: /usr/bin/X -core :0 -seat seat0 -auth /var/run/lightdm/root/:0 -nolisten tcp vt7 -novtswitch
ProcEnviron:

ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.16.0-31-generic root=UUID=3a8fb3f3-1054-45a0-8ec0-0cbeba33da00 ro quiet splash vt.handoff=7
Signal: 6
SourcePackage: xorg-server
StacktraceTop:
 OsAbort ()
 ?? ()
 FatalError ()
 ?? ()
 __libc_start_main (main=0x7ff122917a60, argc=11, argv=0x7fff2bb6df68, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fff2bb6df58) at libc-start.c:287
Title: Xorg crashed with SIGABRT in OsAbort()
UpgradeStatus: Upgraded to utopic on 2014-10-25 (138 days ago)
UserGroups:

dmi.bios.date: 03/25/2011
dmi.bios.vendor: Dell Inc.
dmi.bios.version: A04
dmi.board.name: 0YR8NN
dmi.board.vendor: Dell Inc.
dmi.board.version: A00
dmi.chassis.type: 8
dmi.chassis.vendor: Dell Inc.
dmi.chassis.version: 0.1
dmi.modalias: dmi:bvnDellInc.:bvrA04:bd03/25/2011:svnDellInc.:pnDellSystemXPSL502X:pvr:rvnDellInc.:rn0YR8NN:rvrA00:cvnDellInc.:ct8:cvr0.1:
dmi.product.name: Dell System XPS L502X
dmi.sys.vendor: Dell Inc.
version.compiz: compiz 1:0.9.12+14.10.20140918-0ubuntu1
version.ia32-libs: ia32-libs N/A
version.libdrm2: libdrm2 2.4.56-1
version.libgl1-mesa-dri: libgl1-mesa-dri 10.3.2-0ubuntu0.1
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 10.3.2-0ubuntu0.1
version.xserver-xorg-core: xserver-xorg-core 2:1.16.0-1ubuntu1.3
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.9.0-1ubuntu2
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:7.4.0-2ubuntu2
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.914-1~exp1ubuntu4.2
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.11-1ubuntu2
xserver.bootTime: Thu Mar 12 21:45:48 2015
xserver.configfile: default
xserver.errors:

xserver.logfile: /var/log/Xorg.0.log
xserver.outputs:
 product id 8940
 vendor AUO
xserver.version: 2:1.16.0-1ubuntu1.3

[Apport retracing service (apport)]

Thank you for taking the time to report this crash and helping to make this software better. This particular crash has already been reported and is a duplicate of bug #1338492, so is being marked as such. Please look at the other bug report to see if there is any missing information that you can provide, or to see if there is a workaround for the bug. Additionally, any further discussion regarding the bug should occur in the other report. Please continue to report any other bugs you may find.