latest skype update causes xorg to segfault

[Yuriy Vidineev]

After update skypeforlinux to 8.5.76.55323 I've started to get xorg segfaults when connected to 2 external monitors via docking station.
My setup: Dell XPS 13 9360 + Dell DS1000 USB-C docking station+2 external FullHD Dell monitors.
In xorg logs I can see:

[ 17917.757] (II) LoadModule: "modesetting"
[ 17917.757] (II) Loading /usr/lib/xorg/modules/drivers/modesetting_drv.so
[ 17917.757] (II) Module modesetting: vendor="X.Org Foundation"
[ 17917.757] compiled for 1.18.4, module version = 1.18.4
[ 17917.757] Module class: X.Org Video Driver
[ 17917.757] ABI class: X.Org Video Driver, version 20.0
[ 17917.757] (II) modesetting: Driver for Modesetting Kernel Drivers: kms
[ 17917.759] (II) modeset(0): using drv /dev/dri/card0
[ 17917.759] (EE)
[ 17917.759] (EE) Backtrace:
[ 17917.759] (EE) 0: /usr/lib/xorg/Xorg (xorg_backtrace+0x4e) [0x55c4f0526b6e]
[ 17917.759] (EE) 1: /usr/lib/xorg/Xorg (0x55c4f0374000+0x1b6ef9) [0x55c4f052aef9]
[ 17917.759] (EE) 2: /lib/x86_64-linux-gnu/libc.so.6 (0x7fb6199e2000+0x354b0) [0x7fb619a174b0]
[ 17917.759] (EE) 3: /usr/lib/x86_64-linux-gnu/libpciaccess.so.0 (pci_device_next+0x118) [0x7fb61afd1a38]
[ 17917.759] (EE) 4: /usr/lib/x86_64-linux-gnu/libpciaccess.so.0 (pci_device_find_by_slot+0x3b) [0x7fb61afd1abb]
[ 17917.759] (EE) 5: /usr/lib/x86_64-linux-gnu/libpciaccess.so.0 (pci_device_vgaarb_init+0xaf) [0x7fb61afd37af]
[ 17917.759] (EE) 6: /usr/lib/xorg/Xorg (0x55c4f0374000+0xb1a39) [0x55c4f0425a39]
[ 17917.759] (EE) 7: /usr/lib/xorg/Xorg (xf86BusConfig+0x62) [0x55c4f03fe7a2]
[ 17917.759] (EE) 8: /usr/lib/xorg/Xorg (InitOutput+0x968) [0x55c4f040cd58]
[ 17917.759] (EE) 9: /usr/lib/xorg/Xorg (0x55c4f0374000+0x57be4) [0x55c4f03cbbe4]
[ 17917.759] (EE) 10: /lib/x86_64-linux-gnu/libc.so.6 (__libc_start_main+0xf0) [0x7fb619a02830]
[ 17917.759] (EE) 11: /usr/lib/xorg/Xorg (_start+0x29) [0x55c4f03b6049]
[ 17917.759] (EE)
[ 17917.759] (EE) Segmentation fault at address 0x0
[ 17917.759] (EE)
Fatal server error:
[ 17917.759] (EE) Caught signal 11 (Segmentation fault). Server aborting
[ 17917.759] (EE)
[ 17917.759] (EE)
Please consult the The X.Org Foundation support
         at http://wiki.x.org
 for help.
[ 17917.759] (EE) Please also check the log file at "/var/log/Xorg.1.log" for additional information.
[ 17917.759] (EE)
[ 17917.816] (EE) Server terminated with error (1). Closing log file.

I'm not facing this issue when I'm not connected to external monitors.
Any help will be much appretiated.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: xserver-xorg (not installed)
ProcVersionSignature: Ubuntu 4.10.0-33.37~16.04.1-generic 4.10.17
Uname: Linux 4.10.0-33-generic x86_64
.tmp.unity_support_test.0:

ApportVersion: 2.20.1-0ubuntu2.10
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: Wed Aug 30 18:27:41 2017
DistUpgraded: Fresh install
DistributionChannelDescriptor:
 # This is a distribution channel descriptor
 # For more information see http://wiki.ubuntu.com/DistributionChannelDescriptor
 canonical-oem-somerville-xenial-amd64-20160624-2
DistroCodename: xenial
DistroVariant: ubuntu
EcryptfsInUse: Yes
ExtraDebuggingInterest: Yes, including running git bisection searches
GraphicsCard:
 Intel Corporation Device [8086:5916] (rev 02) (prog-if 00 [VGA controller])
   Subsystem: Dell Device [1028:075b]
InstallationDate: Installed on 2016-10-06 (328 days ago)
InstallationMedia: Ubuntu 16.04 "Xenial" - Build amd64 LIVE Binary 20160624-10:47
Lsusb:
 Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
 Bus 001 Device 003: ID 0c45:670c Microdia
 Bus 001 Device 002: ID 0cf3:e301 Atheros Communications, Inc.
 Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
MachineType: Dell Inc. XPS 13 9360
ProcEnviron:
 LANGUAGE=en_US
 TERM=xterm-256color
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.10.0-33-generic root=UUID=f79f9409-625c-4f78-83af-cf2cf7928690 ro quiet splash vt.handoff=7
SourcePackage: xorg
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 08/02/2017
dmi.bios.vendor: Dell Inc.
dmi.bios.version: 2.1.0
dmi.board.name: 0839Y6
dmi.board.vendor: Dell Inc.
dmi.board.version: A00
dmi.chassis.type: 9
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvr2.1.0:bd08/02/2017:svnDellInc.:pnXPS139360:pvr:rvnDellInc.:rn0839Y6:rvrA00:cvnDellInc.:ct9:cvr:
dmi.product.name: XPS 13 9360
dmi.sys.vendor: Dell Inc.
version.compiz: compiz 1:0.9.12.2+16.04.20160823-0ubuntu1
version.ia32-libs: ia32-libs N/A
version.libdrm2: libdrm2 2.4.76-1~ubuntu16.04.1
version.libgl1-mesa-dri: libgl1-mesa-dri 17.0.7-0ubuntu0.16.04.2
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 17.0.7-0ubuntu0.16.04.2
version.xserver-xorg-core: xserver-xorg-core N/A
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev N/A
version.xserver-xorg-video-ati: xserver-xorg-video-ati N/A
version.xserver-xorg-video-intel: xserver-xorg-video-intel N/A
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau N/A

[Yuriy Vidineev (adeptg)]

My bug @ freedesktop.org
https://bugs.freedesktop.org/show_bug.cgi?id=102485

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Yuriy Vidineev (adeptg)]

Looks like for me issue was fixed agter upgrade to linux 4.13. But I'm not 100% sure yet

[Yuriy Vidineev (adeptg)]

I wasn't able to reproduce with linux 4.13 and 4.14. So I think it was a bug in kernel

[penalvch (penalvch)]

Yuriy Vidineev, thank you for reporting this and helping make Ubuntu better.

To see if this is already resolved in your release, could you please update your HWE stack as per https://wiki.ubuntu.com/Kernel/LTSEnablementStack and advise to the results?

[Yuriy Vidineev (adeptg)]

Hi Christopher,
Thanks for your attention!
Like I said in previous comment I don't have this bug anymore after upgrading to linux 4.13

[penalvch (penalvch)]

Yuriy Vidineev, closing as per your comment https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1714122/comments/7 noting this is resolved by updating.