I think this is an issue with the lightdm(-guest-session) apparmor
profiles.
In dmesg:
laney@yakkety-vm:~$ dmesg | grep DENIED
[ 142.273990] audit: type=1400 audit(1474905574.718:125): apparmor="DENIED"
operation="open" profile="/usr/lib/lightdm/lightdm-guest-session"
name="/proc/sys/kernel/osrelease" pid=2167 comm="pkill" requested_mask="r"
denied_mask="r" fsuid=998 ouid=0
[ 142.274396] audit: type=1400 audit(1474905574.718:126): apparmor="DENIED"
operation="open" profile="/usr/lib/lightdm/lightdm-guest-session"
name="/proc/1/cmdline" pid=2167 comm="pkill" requested_mask="r" denied_mask="r"
fsuid=998 ouid=0
[ 142.274428] audit: type=1400 audit(1474905574.718:127): apparmor="DENIED"
operation="open" profile="/usr/lib/lightdm/lightdm-guest-session"
name="/proc/2/cmdline" pid=2167 comm="pkill" requested_mask="r" denied_mask="r"
fsuid=998 ouid=0
[ 142.274457] audit: type=1400 audit(1474905574.718:128): apparmor="DENIED"
operation="open" profile="/usr/lib/lightdm/lightdm-guest-session"
name="/proc/3/cmdline" pid=2167 comm="pkill" requested_mask="r" denied_mask="r"
fsuid=998 ouid=0
[ 142.274484] audit: type=1400 audit(1474905574.718:129): apparmor="DENIED"
operation="open" profile="/usr/lib/lightdm/lightdm-guest-session"
name="/proc/4/cmdline" pid=2167 comm="pkill" requested_mask="r" denied_mask="r"
fsuid=998 ouid=0
[ 142.274513] audit: type=1400 audit(1474905574.718:130): apparmor="DENIED"
operation="open" profile="/usr/lib/lightdm/lightdm-guest-session"
name="/proc/5/cmdline" pid=2167 comm="pkill" requested_mask="r" denied_mask="r"
fsuid=998 ouid=0
[ 142.274542] audit: type=1400 audit(1474905574.718:131): apparmor="DENIED"
operation="open" profile="/usr/lib/lightdm/lightdm-guest-session"
name="/proc/6/cmdline" pid=2167 comm="pkill" requested_mask="r" denied_mask="r"
fsuid=998 ouid=0
[ 142.274569] audit: type=1400 audit(1474905574.718:132): apparmor="DENIED"
operation="open" profile="/usr/lib/lightdm/lightdm-guest-session"
name="/proc/7/cmdline" pid=2167 comm="pkill" requested_mask="r" denied_mask="r"
fsuid=998 ouid=0
[ 142.274598] audit: type=1400 audit(1474905574.718:133): apparmor="DENIED"
operation="open" profile="/usr/lib/lightdm/lightdm-guest-session"
name="/proc/8/cmdline" pid=2167 comm="pkill" requested_mask="r" denied_mask="r"
fsuid=998 ouid=0
[ 142.274626] audit: type=1400 audit(1474905574.718:134): apparmor="DENIED"
operation="open" profile="/usr/lib/lightdm/lightdm-guest-session"
name="/proc/9/cmdline" pid=2167 comm="pkill" requested_mask="r" denied_mask="r"
fsuid=998 ouid=0
[ 147.434462] audit: type=1400 audit(1474905579.878:282): apparmor="DENIED"
operation="connect" profile="/usr/lib/lightdm/lightdm-guest-session" pid=2843
comm="initctl" family="unix" sock_type="stream" protocol=0 requested_mask="send
receive accept" denied_mask="send accept"
addr="@/com/ubuntu/upstart-session/998/2526" peer_addr=none peer="unconfined"
[ 147.450970] audit: type=1400 audit(1474905579.894:283): apparmor="DENIED"
operation="connect" profile="/usr/lib/lightdm/lightdm-guest-session" pid=2855
comm="initctl" family="unix" sock_type="stream" protocol=0 requested_mask="send
receive accept" denied_mask="send accept"
addr="@/com/ubuntu/upstart-session/998/2526" peer_addr=none peer="unconfined"
[ 147.494563] audit: type=1400 audit(1474905579.938:284): apparmor="DENIED"
operation="connect" profile="/usr/lib/lightdm/lightdm-guest-session" pid=2871
comm="initctl" family="unix" sock_type="stream" protocol=0 requested_mask="send
receive accept" denied_mask="send accept"
addr="@/com/ubuntu/upstart-session/998/2526" peer_addr=none peer="unconfined"
[ 147.511922] audit: type=1400 audit(1474905579.954:285): apparmor="DENIED"
operation="open" profile="/usr/lib/lightdm/lightdm-guest-session"
name="/proc/sys/kernel/osrelease" pid=2879 comm="pkill" requested_mask="r"
denied_mask="r" fsuid=998 ouid=0
[ 147.512279] audit: type=1400 audit(1474905579.958:286): apparmor="DENIED"
operation="open" profile="/usr/lib/lightdm/lightdm-guest-session"
name="/proc/1/cmdline" pid=2879 comm="pkill" requested_mask="r" denied_mask="r"
fsuid=998 ouid=0
[ 147.512303] audit: type=1400 audit(1474905579.958:287): apparmor="DENIED"
operation="open" profile="/usr/lib/lightdm/lightdm-guest-session"
name="/proc/2/cmdline" pid=2879 comm="pkill" requested_mask="r" denied_mask="r"
fsuid=998 ouid=0
[ 147.512322] audit: type=1400 audit(1474905579.958:288): apparmor="DENIED"
operation="open" profile="/usr/lib/lightdm/lightdm-guest-session"
name="/proc/3/cmdline" pid=2879 comm="pkill" requested_mask="r" denied_mask="r"
fsuid=998 ouid=0
[ 147.512340] audit: type=1400 audit(1474905579.958:289): apparmor="DENIED"
operation="open" profile="/usr/lib/lightdm/lightdm-guest-session"
name="/proc/4/cmdline" pid=2879 comm="pkill" requested_mask="r" denied_mask="r"
fsuid=998 ouid=0
[ 147.512356] audit: type=1400 audit(1474905579.958:290): apparmor="DENIED"
operation="open" profile="/usr/lib/lightdm/lightdm-guest-session"
name="/proc/5/cmdline" pid=2879 comm="pkill" requested_mask="r" denied_mask="r"
fsuid=998 ouid=0
[ 147.512373] audit: type=1400 audit(1474905579.958:291): apparmor="DENIED"
operation="open" profile="/usr/lib/lightdm/lightdm-guest-session"
name="/proc/6/cmdline" pid=2879 comm="pkill" requested_mask="r" denied_mask="r"
fsuid=998 ouid=0
In the journal:
Sep 26 16:59:39 yakkety-vm systemd[2518]: Starting Unity Shell v7...
Sep 26 16:59:39 yakkety-vm kernel: audit_printk_skb: 441 callbacks suppressed
Sep 26 16:59:39 yakkety-vm kernel: audit: type=1400 audit(1474905579.878:282):
apparmor="DENIED" operation="connect"
profile="/usr/lib/lightdm/lightdm-guest-session" pid=2843 comm="initctl"
family="
Sep 26 16:59:39 yakkety-vm systemd[2518]: Started GNOME Session Manager.
Sep 26 16:59:39 yakkety-vm sh[2846]: + [ ubuntu != gnome-classic ]
Sep 26 16:59:39 yakkety-vm sh[2846]: + [ ubuntu = gnome-flashback-metacity ]
Sep 26 16:59:39 yakkety-vm sh[2846]: + exec gnome-session --session=ubuntu
Sep 26 16:59:39 yakkety-vm audit[2855]: AVC apparmor="DENIED"
operation="connect" profile="/usr/lib/lightdm/lightdm-guest-session" pid=2855
comm="initctl" family="unix" sock_type="stream" protocol=0
Sep 26 16:59:39 yakkety-vm systemd-prestart-check[2845]: initctl: Unable to
connect to Upstart: Failed to connect to socket
/com/ubuntu/upstart-session/998/2526: Permission denied
Sep 26 16:59:39 yakkety-vm kernel: audit: type=1400 audit(1474905579.894:283):
apparmor="DENIED" operation="connect"
profile="/usr/lib/lightdm/lightdm-guest-session" pid=2855 comm="initctl"
family="
Sep 26 16:59:39 yakkety-vm compiz-profile-selector[2861]: OpenGL vendor string:
VMware, Inc.
Sep 26 16:59:39 yakkety-vm compiz-profile-selector[2861]: OpenGL renderer
string: Gallium 0.4 on llvmpipe (LLVM 3.8, 256 bits)
Sep 26 16:59:39 yakkety-vm compiz-profile-selector[2861]: OpenGL version
string: 3.0 Mesa 12.0.1
Sep 26 16:59:39 yakkety-vm compiz-profile-selector[2861]: Not software
rendered: no
Sep 26 16:59:39 yakkety-vm compiz-profile-selector[2861]: Not blacklisted:
yes
Sep 26 16:59:39 yakkety-vm compiz-profile-selector[2861]: GLX fbconfig:
yes
Sep 26 16:59:39 yakkety-vm compiz-profile-selector[2861]: GLX texture from
pixmap: yes
Sep 26 16:59:39 yakkety-vm compiz-profile-selector[2861]: GL npot or rect
textures: yes
Sep 26 16:59:39 yakkety-vm compiz-profile-selector[2861]: GL vertex program:
yes
Sep 26 16:59:39 yakkety-vm compiz-profile-selector[2861]: GL fragment program:
yes
Sep 26 16:59:39 yakkety-vm compiz-profile-selector[2861]: GL vertex buffer
object: yes
Sep 26 16:59:39 yakkety-vm compiz-profile-selector[2861]: GL framebuffer
object: yes
Sep 26 16:59:39 yakkety-vm compiz-profile-selector[2861]: GL version is 1.4+:
yes
Sep 26 16:59:39 yakkety-vm compiz-profile-selector[2861]: Unity 3D supported:
no
Sep 26 16:59:39 yakkety-vm compiz-profile-selector[2861]: Using compiz profile
'ubuntu-lowgfx'
Sep 26 16:59:39 yakkety-vm audit[2871]: AVC apparmor="DENIED"
operation="connect" profile="/usr/lib/lightdm/lightdm-guest-session" pid=2871
comm="initctl" family="unix" sock_type="stream" protocol=0
Sep 26 16:59:39 yakkety-vm compiz-profile-selector[2861]: initctl: Unable to
connect to Upstart: Failed to connect to socket
/com/ubuntu/upstart-session/998/2526: Permission denied
Sep 26 16:59:39 yakkety-vm systemd[2518]: unity7.service: Control process
exited, code=exited status=1
Sep 26 16:59:39 yakkety-vm systemd[2518]: Failed to start Unity Shell v7.
Sep 26 16:59:39 yakkety-vm systemd[2518]: Dependency failed for User systemd
services for the Ubuntu graphical session.
Sep 26 16:59:39 yakkety-vm systemd[2518]: ubuntu-session.target: Job
ubuntu-session.target/start failed with result 'dependency'.
Sep 26 16:59:39 yakkety-vm systemd[2518]: unity7.service: Unit entered failed
state.
Sep 26 16:59:39 yakkety-vm kernel: audit: type=1400 audit(1474905579.938:284):
apparmor="DENIED" operation="connect"
profile="/usr/lib/lightdm/lightdm-guest-session" pid=2871 comm="initctl"
family="
Sep 26 16:59:39 yakkety-vm systemd[2518]: unity7.service: Failed with result
'exit-code'.
** Also affects: apparmor (Ubuntu)
Importance: Undecided
Status: New
** Tags added: rls-y-incoming
** Changed in: gnome-session (Ubuntu)
Status: Confirmed => Incomplete
** Changed in: lightdm (Ubuntu)
Status: Confirmed => Incomplete
** Changed in: lightdm (Ubuntu)
Status: Incomplete => Triaged
** Changed in: lightdm (Ubuntu)
Importance: Undecided => Critical
** Changed in: apparmor (Ubuntu)
Importance: Undecided => Critical
** Changed in: apparmor (Ubuntu)
Status: New => Triaged
** Changed in: unity-greeter (Ubuntu)
Status: Confirmed => Incomplete
--
You received this bug notification because you are a member of LightDM
Gtk+ Greeter Development Team, which is subscribed to lightdm-gtk-
greeter in Ubuntu.
https://bugs.launchpad.net/bugs/1627304
Title:
User locking problems - guest login crashing
Status in apparmor package in Ubuntu:
Incomplete
Status in gnome-session package in Ubuntu:
Incomplete
Status in lightdm package in Ubuntu:
Triaged
Status in lightdm-gtk-greeter package in Ubuntu:
Incomplete
Status in unity-greeter package in Ubuntu:
Incomplete
Status in xubuntu-default-settings package in Ubuntu:
Incomplete
Bug description:
Vanilla Ubuntu install.
Lock user - login to guest account, desktop crashes. Ctrl+Alt+F7
allows you to resume user after unlocking.
Add new user - am able to switch between locked users properly.
Can logout of one user and be able to resume other locked session.
ProblemType: Bug
DistroRelease: Ubuntu 16.10
Package: lightdm 1.19.4-0ubuntu1
ProcVersionSignature: Ubuntu 4.8.0-14.15-generic 4.8.0-rc7
Uname: Linux 4.8.0-14-generic x86_64
ApportVersion: 2.20.3-0ubuntu7
Architecture: amd64
CurrentDesktop: Unity
Date: Sat Sep 24 13:38:09 2016
InstallationDate: Installed on 2016-09-24 (0 days ago)
InstallationMedia: Ubuntu 16.10 "Yakkety Yak" - Alpha amd64 (20160922)
SourcePackage: lightdm
UpgradeStatus: No upgrade log present (probably fresh install)
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/apparmor/+bug/1627304/+subscriptions
--
Mailing list: https://launchpad.net/~lightdm-gtk-greeter-team
Post to : lightdm-gtk-greeter-team@lists.launchpad.net
Unsubscribe : https://launchpad.net/~lightdm-gtk-greeter-team
More help : https://help.launchpad.net/ListHelp
