Upstream github issue: https://github.com/canonical/lightdm/issues/185
** Bug watch added: github.com/canonical/lightdm/issues #185 https://github.com/canonical/lightdm/issues/185 ** Changed in: lightdm (Ubuntu) Status: New => Triaged ** Changed in: lightdm (Ubuntu) Importance: Undecided => Medium -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to lightdm in Ubuntu. https://bugs.launchpad.net/bugs/1921655 Title: lightdm-guest-session ICEauthority error Status in Ubuntu MATE: New Status in lightdm package in Ubuntu: Triaged Bug description: Hello I ran into trouble to start the lightdm-guest-session in linux mint (cinnamon). ## How to reproduce: - boot linux mint (20.02) or ubuntu mate (20.04) I haven't tested other distros but I think others are also affected. - enable guest user session - try to login as guest user ## Error logs: ### Error Message: ` Could not update file ICEauthority file /run/user/XXX/ICEauthority` ### aa-notify: ``` Profile: /usr/lib/lightdm/lightdm-guest-session Operation: open Name: /proc/8125/uid_map Denied: w Logfile: /var/log/kern.log Profile: /usr/lib/lightdm/lightdm-guest-session Operation: open Name: /proc/8125/setgroups Denied: w Logfile: /var/log/kern.log Profile: /usr/lib/lightdm/lightdm-guest-session Operation: open Name: /proc/8125/gid_map Denied: w Logfile: /var/log/kern.log Profile: /usr/lib/lightdm/lightdm-guest-session Operation: open Name: /proc/8624/fd/ Denied: r Logfile: /var/log/kern.log ``` ### dmesg: ``` [ 218.831289] audit: type=1400 audit(1616864450.287:76): apparmor="DENIED" operation="sendmsg" profile="/usr/lib/lightdm/lightdm-guest-session" name="/run/systemd/journal/dev-log" pid=3916 comm="cinnamon-sessio" requested_mask="w" denied_mask="w" fsuid=999 ouid=0 [ 1157.263045] audit: type=1400 audit(1616865388.720:1084): apparmor="DENIED" operation="open" profile="/usr/lib/lightdm/lightdm-guest-session" name="/proc/9899/fd/" pid=9899 comm="gpg-agent" requested_mask="r" denied_mask="r" fsuid=999 #ouid=0 [ 1157.899223] audit: type=1400 audit(1616865389.356:1085): apparmor="DENIED" operation="open" profile="/usr/lib/lightdm/lightdm-guest-session" name="/proc/1/cgroup" pid=9840 comm="cinnamon-sessio" requested_mask="r" denied_mask="r" fsuid=999 ouid=0 [ 1157.899445] audit: type=1400 audit(1616865389.360:1086): apparmor="DENIED" operation="sendmsg" profile="/usr/lib/lightdm/lightdm-guest-session" name="/run/systemd/journal/dev-log" pid=9840 comm="cinnamon-sessio" requested_mask="w" denied_mask="w" fsuid=999 ouid=0 [ 1157.903410] audit: type=1400 audit(1616865389.364:1087): apparmor="DENIED" operation="link" profile="/usr/lib/lightdm/lightdm-guest-session" name="/run/user/999/ICEauthority-l" pid=9840 comm="cinnamon-sessio" requested_mask="l" denied_mask="l" fsuid=999 ouid=999 target="/run/user/999/ICEauthority-c" ``` ## Solutions: ### bad but common work around Solutions I found in different forums were to move lightdm-guest-session into complain mode like this: `aa-complain /usr/lib/lightdm/lightdm-guest-session` ### maybe better sollution: My fix would be to add this to `/etc/apparmor.d/lightdm-guest-session`: ``` ... /usr/lib/lightdm/lightdm-guest-session { ... owner /run/user/[0-9]*/ICEauthority-? l,` ... } ``` I honestly have no clue about apparmor and I'm unsure where to post this but I hope this maybe helps some other people in the future. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-mate/+bug/1921655/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp