gnome-shell crashed with SIGSEGV in meta_window_update_for_monitors_changed()

[Rachel Greenham]

Pair this with bug #1723615: This one actually happened first, and was presumably the event that ended my gnome desktop session. Then the other one happened about 18 minutes later and happened to gdm's gnome-shell. Both occurred while I was away from the computer and the system should have been in displaysleep but not suspended.

ProblemType: Crash
DistroRelease: Ubuntu 17.10
Package: gnome-shell 3.26.1-0ubuntu3
ProcVersionSignature: Ubuntu 4.13.0-16.19-generic 4.13.4
Uname: Linux 4.13.0-16-generic x86_64
NonfreeKernelModules: nvidia_uvm nvidia_drm nvidia_modeset nvidia
ApportVersion: 2.20.7-0ubuntu3
Architecture: amd64
CrashCounter: 1
CurrentDesktop: GNOME
Date: Sat Oct 14 15:21:47 2017
DisplayManager: gdm3
ExecutablePath: /usr/bin/gnome-shell
InstallationDate: Installed on 2017-07-30 (75 days ago)
InstallationMedia: Ubuntu-GNOME 17.04 "Zesty Zapus" - Release amd64 (20170412)
ProcCmdline: /usr/bin/gnome-shell
ProcEnviron:
 LANGUAGE=en_GB:en
 PATH=(custom, user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_GB.UTF-8
 SHELL=/bin/bash
SegvAnalysis:
 Segfault happened at: 0x7fd78c4b0e60 <meta_window_update_for_monitors_changed+192>: mov 0x40(%rbp),%edi
 PC (0x7fd78c4b0e60) ok
 source "0x40(%rbp)" (0x00000040) not located in a known VMA region (needed readable region)!
 destination "%edi" ok
SegvReason: reading NULL VMA
Signal: 11
SourcePackage: gnome-shell
StacktraceTop:
 meta_window_update_for_monitors_changed () at /usr/lib/x86_64-linux-gnu/libmutter-1.so.0
 g_slist_foreach () at /lib/x86_64-linux-gnu/libglib-2.0.so.0
 meta_screen_foreach_window () at /usr/lib/x86_64-linux-gnu/libmutter-1.so.0
 () at /usr/lib/x86_64-linux-gnu/libmutter-1.so.0
 g_closure_invoke () at /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
Title: gnome-shell crashed with SIGSEGV in meta_window_update_for_monitors_changed()
UpgradeStatus: Upgraded to artful on 2017-08-22 (53 days ago)
UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo

[Apport retracing service (apport)]

StacktraceTop:
 meta_window_update_for_monitors_changed (window=0x55a718ab4860) at core/window.c:3797
 g_slist_foreach (list=<optimized out>, list@entry=0x55a713076dc0, func=func@entry=0x7fd78c4b0da0 <meta_window_update_for_monitors_changed>, user_data=user_data@entry=0x0) at ../../../../glib/gslist.c:880
 meta_screen_foreach_window (screen=<optimized out>, flags=<optimized out>, func=0x7fd78c4b0da0 <meta_window_update_for_monitors_changed>, data=0x0) at core/screen.c:979
 on_monitors_changed_internal (manager=<optimized out>, screen=0x55a7107125b0) at core/screen.c:2300
 g_closure_invoke (closure=0x55a7107eb410, return_value=0x0, n_param_values=1, param_values=0x7ffcba86dd50, invocation_hint=0x7ffcba86dcd0) at ../../../../gobject/gclosure.c:804

[Launchpad Janitor (janitor)]

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

[Rachel Greenham (rachel-strangenoises)]

Just poking in to say this is still happening, and not magically fixed by Artful's release date. It happened today, but trying to ubuntu-bug the crash file failed. (It just quit when I clicked Continue.)

One difference today: Thinking maybe my screen-sleep woes were partly because of gnome shell being in lock mode, I tried instead disabling screen lock and suspend and just using ye olde x11 screen blanking to standby, ie: xset dpms 1200 0 0. It still died, leaving a crash file reporting this same error, at the time I tried to wake things up again. I think again, supported by the description of this bug, it was probably due to slowness in monitors waking up, or one of them having problems waking up fully at all, then gnome-shell responds ungracefully - perhaps even disgracefully - to the change in monitors. gnome shell is so damn fragile.

gnome-shell 3.26.1-0ubuntu5

[Marco Trevisan (Treviño) (3v1n0)]

Tracked also https://errors.ubuntu.com/problem/1e5fd96ce7891bcb3574896dcdff05237fc4549f

[Daniel van Vugt (vanvugt)]

Fix Released, apparently. Zero reports of this crash after 17.10.