Activating pam_kwallet5.so in lightdm pam configuration restarts user sessions

[Christoph]

Hello,

I had a problem with lightdm: After logging out from a user session, the login screen did not appear again, but instead the session restarted automatically. This happened several times one after another, until finally the third or fourth logout attempts was successful. While investigating this, I discovered a difference from another computer with the same lightdm upstream version, but without the problem: On the Ubuntu machine, lightdm had one child process owned by root and two child processes owned by the logged-in user, while on the other machine lightdm had only the child process owned by root.

Result of my investigation was: All this could be solved by either commenting out the pam_kwallet5.so module from /etc/pam.d/lightdm or downgrading libpam-kwallet5 from 4:5.12.4-0ubuntu1.3 to 4:5.12.4-0ubuntu1.

I am using Ubuntu version 18.04 and lightm version 1.26.0-0ubuntu1.

Regards
  Christoph

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: libpam-kwallet5 4:5.12.4-0ubuntu1
ProcVersionSignature: Ubuntu 4.15.0-33.36-generic 4.15.18
Uname: Linux 4.15.0-33-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.2
Architecture: amd64
CurrentDesktop: GNOME
Date: Fri Aug 31 11:22:59 2018
InstallationDate: Installed on 2018-06-06 (85 days ago)
InstallationMedia: Ubuntu 18.04 LTS "Bionic Beaver" - Release amd64 (20180426)
SourcePackage: kwallet-pam
UpgradeStatus: No upgrade log present (probably fresh install)

[Christoph (christoph-pleger-cs)]

Depending on the selected user session type, the logout problem also occurs with pam_kwallet.so and pam_gnome_keyring.so (strange, how can the user session type affect what the pam modules and/or lightdm do). Maybe this is not a bug in the pam modules, but in lightdm?

[Christoph (christoph-pleger-cs)]

Well, somehow today I had different results from yesterday: All user session types had the same result and only pam_kwallet.so and pam_kwallet5.so caused problems. I guess that yesterday I mixed up several things when trying different lightdm versions and different pam configurations.

[Scarlett Gately Moore (scarlettmoore)]

This bug is very old, if it is still an issue please update the bug with information from a supported release.