gnome-shell crashed with SIGSEGV in meta_window_unmaximize() from update_move() from meta_window_handle_mouse_grab_op_event() from meta_display_handle_event()

[James_Ward]

https://errors.ubuntu.com/problem/5fb0c783621f10ac741a0a841432fcc9a74ca69c

---

I did not notice anything, but the system reported a crash. This is a macbookpro14,3 kernel 4.18.

ProblemType: Crash
DistroRelease: Ubuntu 18.04
Package: gnome-shell 3.28.2-0ubuntu0.18.04.1
Uname: Linux 4.18.0-041800-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.2
Architecture: amd64
CurrentDesktop: GNOME
Date: Tue Aug 14 12:38:19 2018
DisplayManager: gdm3
ExecutablePath: /usr/bin/gnome-shell
GsettingsChanges:
 b'org.gnome.shell' b'had-bluetooth-devices-setup' b'true'
 b'org.gnome.shell' b'favorite-apps' redacted by apport
 b'org.gnome.desktop.interface' b'gtk-im-module' b"'gtk-im-context-simple'"
InstallationDate: Installed on 2018-08-09 (4 days ago)
InstallationMedia: Ubuntu 18.04 LTS "Bionic Beaver" - Release amd64 (20180426)
ProcCmdline: /usr/bin/gnome-shell
ProcEnviron:
 PATH=(custom, user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SegvAnalysis:
 Segfault happened at: 0x7f598429b278 <meta_window_unmaximize+200>: mov 0x18(%rax),%esi
 PC (0x7f598429b278) ok
 source "0x18(%rax)" (0x00000018) not located in a known VMA region (needed readable region)!
 destination "%esi" ok
SegvReason: reading NULL VMA
Signal: 11
SourcePackage: gnome-shell
StacktraceTop:
 meta_window_unmaximize () from /usr/lib/x86_64-linux-gnu/libmutter-2.so.0
 ?? () from /usr/lib/x86_64-linux-gnu/libmutter-2.so.0
 meta_window_handle_mouse_grab_op_event () from /usr/lib/x86_64-linux-gnu/libmutter-2.so.0
 ?? () from /usr/lib/x86_64-linux-gnu/libmutter-2.so.0
 ?? () from /usr/lib/x86_64-linux-gnu/mutter/libmutter-clutter-2.so
Title: gnome-shell crashed with SIGSEGV in meta_window_unmaximize()
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm cdrom chrome-remote-desktop dip lpadmin plugdev sambashare sudo

[Apport retracing service (apport)]

StacktraceTop:
 meta_window_unmaximize (window=window@entry=0x55e4e71818a0, directions=directions@entry=META_MAXIMIZE_BOTH) at core/window.c:3250
 update_move (window=window@entry=0x55e4e71818a0, snap=snap@entry=0, x=<optimized out>, y=954) at core/window.c:6056
 meta_window_handle_mouse_grab_op_event (window=window@entry=0x55e4e71818a0, event=event@entry=0x55e4e7e04570) at core/window.c:6420
 meta_display_handle_event (event=0x55e4e7e04570, display=0x55e4e5bfb600) at core/events.c:299
 event_callback (event=0x55e4e7e04570, data=0x55e4e5bfb600) at core/events.c:423

[Launchpad Janitor (janitor)]

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

[Daniel van Vugt (vanvugt)]

Also tracking in:
https://errors.ubuntu.com/problem/5fb0c783621f10ac741a0a841432fcc9a74ca69c

[Daniel van Vugt (vanvugt)]

This is strange. No crashes in focal but a few in groovy(?)