segfault at 0 ip 000055ab7770b810 sp 00007ffed925ea88 error 6 in dbus-daemon[55ab776ef000+35000]

[David R. Hedges]

update-notifier had informed me of a few new updates to install[1]. I clicked the button to proceed with the upgrade, and a few seconds later, the screen went black, and after another few seconds I was returned to the login screen (my session was not maintained). The syslog around the time of the crash includes the following:

--------------------
Jun 18 09:24:07 sydney dbus[1079]: [system] Successfully activated service 'org.debian.apt'
Jun 18 09:24:07 sydney AptDaemon: INFO: CommitPackages() was called: dbus.Array([dbus.String('')], signature=dbus.Signature('s')), dbus.Array([dbus.String('')], signature=dbus.Signature('s')), dbus.Array([dbus.String('')], signature=dbus.Signature('s')), dbus.Array([dbus.String('')], signature=dbus.Signature('s')), dbus.Array([dbus.String('libnm-glib-vp
n1'), dbus.String('libnm-glib4'), dbus.String('libnm-util2'), dbus.String('libnm0'), dbus.String('network-manager')], signature=dbus.Signature('s')), dbus.Array([dbus.String('')], signature=dbus.Signature('s'))
Jun 18 09:24:07 sydney org.debian.apt[1079]: /usr/lib/python3/dist-packages/aptdaemon/worker/pkworker.py:35: PyGIWarning: PackageKitGlib was imported without specifying a version first. Use gi.require_version('PackageKitGlib', '1.0') before import to ensure that the right version gets loaded.
Jun 18 09:24:07 sydney org.debian.apt[1079]: from gi.repository import PackageKitGlib as pk
Jun 18 09:24:07 sydney org.debian.apt[1079]: 09:24:07 AptDaemon [INFO]: CommitPackages() was called: dbus.Array([dbus.String('')], signature=dbus.Signature('s')), dbus.Array([dbus.String('')], signature=dbus.Signature('s')), dbus.Array([dbus.String('')], signature=dbus.Signature('s')), dbus.Array([dbus.String('')], signature=dbus.Signature('s')), dbus.A
rray([dbus.String('libnm-glib-vpn1'), dbus.String('libnm-glib4'), dbus.String('libnm-util2'), dbus.String('libnm0'), dbus.String('network-manager')], signature=dbus.Signature('s')), dbus.Array([dbus.String('')], signature=dbus.Signature('s'))
Jun 18 09:24:07 sydney AptDaemon.Trans: INFO: Queuing transaction /org/debian/apt/transaction/31030c254a96421dab61bc4517ef8c37
Jun 18 09:24:07 sydney org.debian.apt[1079]: 09:24:07 AptDaemon.Trans [INFO]: Queuing transaction /org/debian/apt/transaction/31030c254a96421dab61bc4517ef8c37
Jun 18 09:24:07 sydney AptDaemon.Worker: INFO: Simulating trans: /org/debian/apt/transaction/31030c254a96421dab61bc4517ef8c37
Jun 18 09:24:07 sydney org.debian.apt[1079]: 09:24:07 AptDaemon.Worker [INFO]: Simulating trans: /org/debian/apt/transaction/31030c254a96421dab61bc4517ef8c37
Jun 18 09:24:08 sydney AptDaemon.Worker: INFO: Committing packages: dbus.Array([], signature=dbus.Signature('s')), dbus.Array([], signature=dbus.Signature('s')), dbus.Array([], signature=dbus.Signature('s')), dbus.Array([], signature=dbus.Signature('s')), dbus.Array([dbus.String('libnm-glib-vpn1'), dbus.String('libnm-glib4'), dbus.String('libnm-util2'),
 dbus.String('libnm0'), dbus.String('network-manager')], signature=dbus.Signature('s')), dbus.Array([], signature=dbus.Signature('s'))
Jun 18 09:24:08 sydney org.debian.apt[1079]: 09:24:08 AptDaemon.Worker [INFO]: Committing packages: dbus.Array([], signature=dbus.Signature('s')), dbus.Array([], signature=dbus.Signature('s')), dbus.Array([], signature=dbus.Signature('s')), dbus.Array([], signature=dbus.Signature('s')), dbus.Array([dbus.String('libnm-glib-vpn1'), dbus.String('libnm-glib
4'), dbus.String('libnm-util2'), dbus.String('libnm0'), dbus.String('network-manager')], signature=dbus.Signature('s')), dbus.Array([], signature=dbus.Signature('s'))
Jun 18 09:24:08 sydney AptDaemon.Worker: INFO: Processing transaction /org/debian/apt/transaction/31030c254a96421dab61bc4517ef8c37
Jun 18 09:24:08 sydney org.debian.apt[1079]: 09:24:08 AptDaemon.Worker [INFO]: Processing transaction /org/debian/apt/transaction/31030c254a96421dab61bc4517ef8c37
Jun 18 09:24:09 sydney update-notifier.desktop[24929]: debconf: DbDriver "passwords" warning: could not open /var/cache/debconf/passwords.dat: Permission denied
Jun 18 09:24:10 sydney update-notifier.desktop[24929]: debconf: DbDriver "passwords" warning: could not open /var/cache/debconf/passwords.dat: Permission denied
Jun 18 09:24:11 sydney dbus-daemon[1079]: Unknown group "power" in message bus configuration file
Jun 18 09:24:11 sydney dbus[1079]: [system] Unable to reload configuration: (null)
Jun 18 09:24:11 sydney dbus-daemon[1079]: Unable to reload configuration: (null)
Jun 18 09:24:11 sydney dbus-daemon[1079]: Unknown group "power" in message bus configuration file
Jun 18 09:24:11 sydney systemd[32207]: telepathy-mission-control-5.service: Main process exited, code=exited, status=1/FAILURE
Jun 18 09:24:11 sydney kernel: [214417.248073] dbus-daemon[1079]: segfault at 0 ip 000055ab7770b810 sp 00007ffed925ea88 error 6 in dbus-daemon[55ab776ef000+35000]
Jun 18 09:24:11 sydney systemd[32207]: telepathy-mission-control-5.service: Unit entered failed state.
Jun 18 09:24:11 sydney systemd[32207]: telepathy-mission-control-5.service: Failed with result 'exit-code'.
Jun 18 09:24:11 sydney kernel: [214417.406021] traps: unity-greeter-s[1676] trap int3 ip:7f40a2202de1 sp:7ffe762686c0 error:0
Jun 18 09:24:11 sydney kernel: [214417.406027] in libglib-2.0.so.0.5200.0[7f40a21b3000+111000]
Jun 18 09:24:11 sydney compiz[24602]: [25104:25151:0618/092411.683826:FATAL:bus.cc(1197)] D-Bus connection was disconnected. Aborting.
Jun 18 09:24:11 sydney compiz[24602]: #0 0x7ff45fc2d9c7 base::debug::StackTrace::StackTrace()
Jun 18 09:24:12 sydney compiz[24602]: #1 0x7ff45fc4c2dc logging::LogMessage::~LogMessage()
Jun 18 09:24:12 sydney compiz[24602]: #2 0x7ff4569972ae dbus::Bus::OnConnectionDisconnectedFilter()
Jun 18 09:24:12 sydney compiz[24602]: #3 0x7ff4441272a1 dbus_connection_dispatch
Jun 18 09:24:12 sydney compiz[24602]: #4 0x7ff456997ee9 dbus::Bus::ProcessAllIncomingDataIfAny()
Jun 18 09:24:12 sydney compiz[24602]: #5 0x7ff45fc2e492 base::debug::TaskAnnotator::RunTask()
Jun 18 09:24:12 sydney compiz[24602]: #6 0x7ff45fc54dcd base::MessageLoop::RunTask()
Jun 18 09:24:12 sydney compiz[24602]: #7 0x7ff45fc55878 base::MessageLoop::DoWork()
Jun 18 09:24:12 sydney compiz[24602]: #8 0x7ff45fc57af9 base::MessagePumpLibevent::Run()
Jun 18 09:24:12 sydney compiz[24602]: #9 0x7ff45fc54af9 base::MessageLoop::RunHandler()
Jun 18 09:24:12 sydney compiz[24602]: #10 0x7ff45fc81140 base::RunLoop::Run()
Jun 18 09:24:12 sydney compiz[24602]: #11 0x7ff45fcb54f7 base::Thread::ThreadMain()
Jun 18 09:24:12 sydney compiz[24602]: #12 0x7ff45fcafad3 <unknown>
Jun 18 09:24:12 sydney compiz[24602]: #13 0x7ff45ff436da start_thread
Jun 18 09:24:12 sydney compiz[24602]: #14 0x7ff44ad7617f clone
Jun 18 09:24:12 sydney compiz[24602]: Received signal 6
Jun 18 09:24:12 sydney compiz[24602]: #0 0x7ff45fc2d9c7 base::debug::StackTrace::StackTrace()
Jun 18 09:24:12 sydney compiz[24602]: #1 0x7ff45fc2d53f <unknown>
Jun 18 09:24:12 sydney compiz[24602]: #2 0x7ff45ff4d670 <unknown>
Jun 18 09:24:12 sydney compiz[24602]: #3 0x7ff44aca377f gsignal
Jun 18 09:24:12 sydney compiz[24602]: #4 0x7ff44aca537a abort
Jun 18 09:24:12 sydney compiz[24602]: #5 0x7ff45fc2b6d2 base::debug::BreakDebugger()
Jun 18 09:24:12 sydney compiz[24602]: #6 0x7ff45fc4c5da logging::LogMessage::~LogMessage()
Jun 18 09:24:12 sydney compiz[24602]: #7 0x7ff4569972ae dbus::Bus::OnConnectionDisconnectedFilter()
Jun 18 09:24:12 sydney compiz[24602]: #8 0x7ff4441272a1 dbus_connection_dispatch
Jun 18 09:24:12 sydney compiz[24602]: #9 0x7ff456997ee9 dbus::Bus::ProcessAllIncomingDataIfAny()
Jun 18 09:24:12 sydney compiz[24602]: #10 0x7ff45fc2e492 base::debug::TaskAnnotator::RunTask()
Jun 18 09:24:12 sydney compiz[24602]: #11 0x7ff45fc54dcd base::MessageLoop::RunTask()
Jun 18 09:24:12 sydney compiz[24602]: #12 0x7ff45fc55878 base::MessageLoop::DoWork()
Jun 18 09:24:12 sydney compiz[24602]: #13 0x7ff45fc57af9 base::MessagePumpLibevent::Run()
Jun 18 09:24:12 sydney compiz[24602]: #14 0x7ff45fc54af9 base::MessageLoop::RunHandler()
Jun 18 09:24:12 sydney compiz[24602]: #15 0x7ff45fc81140 base::RunLoop::Run()
Jun 18 09:24:12 sydney compiz[24602]: #16 0x7ff45fcb54f7 base::Thread::ThreadMain()
Jun 18 09:24:12 sydney compiz[24602]: #17 0x7ff45fcafad3 <unknown>
Jun 18 09:24:12 sydney compiz[24602]: #18 0x7ff45ff436da start_thread
Jun 18 09:24:12 sydney compiz[24602]: #19 0x7ff44ad7617f clone
Jun 18 09:24:12 sydney compiz[24602]: r8: 0000000000000000 r9: 00007ff41effbc30 r10: 0000000000000008 r11: 0000000000000246
Jun 18 09:24:12 sydney compiz[24602]: r12: 00007ff41effc2f0 r13: 0000555cc8485338 r14: 00007ff41effc300 r15: 00007ff44b6c4060
Jun 18 09:24:12 sydney compiz[24602]: di: 0000000000000002 si: 00007ff41effbc30 bp: 0000555cc83c5a20 bx: 0000000000000000
Jun 18 09:24:12 sydney compiz[24602]: dx: 0000000000000000 ax: 0000000000000000 cx: 00007ff44aca377f sp: 00007ff41effbca8
Jun 18 09:24:12 sydney NetworkManager[1104]: <warn> [1497795851.6845] bus-manager: disconnected by the system bus
Jun 18 09:24:12 sydney gnome-session-binary[24495]: GLib-GObject-CRITICAL: g_object_unref: assertion 'G_IS_OBJECT (object)' failed
Jun 18 09:24:12 sydney gnome-session[24495]: gnome-session-binary[24495]: GLib-GObject-CRITICAL: g_object_unref: assertion 'G_IS_OBJECT (object)' failed
Jun 18 09:24:12 sydney gnome-session[24495]: gnome-session-binary[24495]: GLib-GObject-CRITICAL: g_object_unref: assertion 'G_IS_OBJECT (object)' failed
Jun 18 09:24:12 sydney lightdm[1427]: Failed to get D-Bus connection
Jun 18 09:24:12 sydney compiz[24602]: ip: 00007ff44aca377f efl: 0000000000000246 cgf: 002b000000000033 erf: 0000000000000000
Jun 18 09:24:12 sydney compiz[24602]: trp: 0000000000000000 msk: 0000000000000000 cr2: 0000000000000000
Jun 18 09:24:12 sydney compiz[24602]: [end of stack trace]
Jun 18 09:24:12 sydney compiz[24602]: Calling _exit(1). Core file will not be generated.
Jun 18 09:24:12 sydney [24702]: Owner of volume monitor org.gtk.vfs.UDisks2VolumeMonitor disconnected from the bus; removing drives/volumes/mounts
Jun 18 09:24:12 sydney gnome-session-binary[24495]: GLib-GObject-CRITICAL: g_object_unref: assertion 'G_IS_OBJECT (object)' failed
Jun 18 09:24:12 sydney compiz[24602]: Catching signal : Terminated
Jun 18 09:24:12 sydney unity-files-dae[17381]: Owner of volume monitor org.gtk.vfs.UDisks2VolumeMonitor disconnected from the bus; removing drives/volumes/mounts
Jun 18 09:24:12 sydney avahi-daemon[1103]: Disconnected from D-Bus, exiting.
Jun 18 09:24:12 sydney sh[4409]: + [ /org/freedesktop/DisplayManager/Session14 = /org/freedesktop/DisplayManager/Session14 ]
Jun 18 09:24:12 sydney sh[4409]: + /usr/bin/dbus-send --type=method_call --address= /com/ubuntu/Upstart com.ubuntu.Upstart0_6.EndSession
Jun 18 09:24:12 sydney compiz[24602]: /usr/bin/compiz (core) - Info: Stopping plugin: unityshell
Jun 18 09:24:12 sydney compiz[24602]: ERROR 2017-06-18 09:24:11 unity.session.gnome GnomeSessionManager.cpp:607 Impossible to get the user path: The connection is closed
--------------------

The referenced missing 'power' group comes from /etc/dbus-1/system.d/org.freedesktop.thermald.conf (from the package thermald).

[1] I'm not sure if it's relevant, but the packages were: libnm-glib4:amd64 (1.4.4-1ubuntu3, 1.4.4-1ubuntu3.1), libnm-glib-vpn1:amd64 (1.4.4-1ubuntu3, 1.4.4-1ubuntu3.1), libnm0:amd64 (1.4.4-1ubuntu3, 1.4.4-1ubuntu3.1), network-manager:amd64 (1.4.4-1ubuntu3, 1.4.4-1ubuntu3.1), libnm-util2:amd64 (1.4.4-1ubuntu3, 1.4.4-1ubuntu3.1)

ProblemType: Bug
DistroRelease: Ubuntu 17.04
Package: dbus 1.10.10-1ubuntu2
ProcVersionSignature: Ubuntu 4.10.0-22.24-generic 4.10.15
Uname: Linux 4.10.0-22-generic x86_64
ApportVersion: 2.20.4-0ubuntu4.1
Architecture: amd64
CurrentDesktop: Unity:Unity7
Date: Sun Jun 18 09:29:27 2017
InstallationDate: Installed on 2014-11-29 (931 days ago)
InstallationMedia: Ubuntu 14.10 "Utopic Unicorn" - Release amd64 (20141022.1)
SourcePackage: dbus
UpgradeStatus: Upgraded to zesty on 2017-04-14 (65 days ago)