login screen freezes when switching users

[Jurgen Schellaert]

Switching users causes the login screen to lock up and the mouse and keyboard to become unresponsive.

The order is this:
1) I select "switch user..." from the top bar
2) the login screen pops up and displays the list of users
2) I select my user
4) I enter the password
5) the screen turns black for 2-3 seconds (this is much longer than usual)
6) the login screen pops up again, this time with the text "password" in the input box; the gear in the bottom right corner to select the type of session is missing; the mouse and keyboard are unresponsive
7) I need to reboot

I have tried disabling Wayland (uncommented WaylandEnable=false in /etc/gdm3/custom.conf) but that does not make any difference.

I do not know whether this may be related, but I have had to disabled the nvidia systemd services because my system failed to suspend until I did (nvidia driver 470).

ProblemType: Bug
DistroRelease: Ubuntu 21.10
Package: gdm3 41~rc-0ubuntu2
ProcVersionSignature: Ubuntu 5.13.0-22.22-generic 5.13.19
Uname: Linux 5.13.0-22-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.20.11-0ubuntu71
Architecture: amd64
CasperMD5CheckResult: pass
CurrentDesktop: ubuntu:GNOME
Date: Sun Dec 12 12:11:57 2021
InstallationDate: Installed on 2021-10-12 (61 days ago)
InstallationMedia: Ubuntu 21.10 "Impish Indri" - Beta amd64 (20210922)
SourcePackage: gdm3
UpgradeStatus: No upgrade log present (probably fresh install)

[Daniel van Vugt (vanvugt)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. It sounds like some part of the system has crashed. To help us find the cause of the crash please follow these steps:

1. Look in /var/crash for crash files and if found run:
    ubuntu-bug YOURFILE.crash
Then tell us the ID of the newly-created bug.

2. If step 1 failed then look at https://errors.ubuntu.com/user/ID where ID is the content of file /var/lib/whoopsie/whoopsie-id on the machine. Do you find any links to recent problems on that page? If so then please send the links to us.

3. If step 2 also failed then apply the workaround from bug 994921, reboot, reproduce the crash, and retry step 1.

Please take care to avoid attaching .crash files to bugs as we are unable to process them as file attachments. It would also be a security risk for yourself.

[Jurgen Schellaert (jurgen-schellaert-j)]

Using method 2, I have found one (recent) link that refers to an issue affecting gdm3:
https://errors.ubuntu.com/oops/10ce3186-5b3e-11ec-88a3-fa163e983629

I hope that this sort of link is what you were asking for; I do not seem to have permission to access its contents so I cannot tell.

[Daniel van Vugt (vanvugt)]

That gdm3 crash report suggests the failure was

Dec 12 12:24:24 Dapple gdm-launch-environment][27459]: GLib-GObject: g_object_unref: assertion 'G_IS_OBJECT (object)' failed
Dec 12 12:24:24 Dapple systemd[1]: gdm.service: Main process exited, code=dumped, status=11/SEGV

Also your Xorg server crashed with bug 1543192 (which I think is usually associated with Nvidia). That certainly would not help but it's a different bug.

The gdm3 issue might also be related to bug 1945061.

[Launchpad Janitor (janitor)]

[Expired for gdm3 (Ubuntu) because there has been no activity for 60 days.]