gdm3 hangs, entering password not possible

[spi]

Whether I am using autofs or systemd automount units to mount network shares (mainly cifs), gdm3 hangs regularly as soon my notebook returns from suspend mode and the user enters their password.

With automount being disabled gdm3 doesn't hang.

1) lsb_release -rd
Description: Ubuntu 18.04.4 LTS
Release: 18.04

2) gdm3:
  Installiert: 3.28.3-0ubuntu18.04.4
gnome-shell:
  Installiert: 3.28.4-0ubuntu18.04.3

3) I'd expect to gdm3 to login the user after authenticating the user.

4) gdm3 hangs after the user typed in their password.

Steps to reproduce - as an example a samba network share gets mounted in /shares/transfer:

a) The notebook is connected to network via ethernet.
b) Network share gets mounted by automounter (eg. ls /shares/transfer).
c) As soon the share is mounted suspend the notebook.
d) Disconnect ethernet (eg. undocking the notebook).
e) Power on the notebook (in undocked state with no ethernet connected).
f) Whether the notebook has a wifi connection or not, after typing in the password, gdm3 hangs. tty logins still possible, hanging automounter connection is to see.

My current workaround:
I am using a systemd unit to unmount all automatically mounted network shares. Additional NetworkManager dispatcher script kills network connection to file server in case network device changes with automounts being active.

[Sebastien Bacher (seb128)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. Please execute the following command, as it will automatically gather debugging information, in a terminal:

  apport-collect 1874835

When reporting bugs in the future please use apport by using 'ubuntu-bug' and the name of the package affected. You can learn more about this functionality at https://wiki.ubuntu.com/ReportingBugs.

[spi (spi-gmxpro)]

I'd like to but there is an issue with apport-collect.

apport-collect 1874835 throws an error "ERROR: The python3-launchpadlib package is not installed. This functionality is not available." But it is installed:

apport 2.20.9-0ubuntu7.14
apport-gtk 2.20.9-0ubuntu7.14
apport-symptoms 0.20
python3-apport 2.20.9-0ubuntu7.14
python3-launchpadlib 1.10.6-1
python3-problem-report 2.20.9-0ubuntu7.14

"python3 -c 'import apport'" shows no error.

Am I missing something?

[spi (spi-gmxpro)]

For whatever reason 'apport-collect 1874835' doesn't work. Used 'python3 /usr/bin/apport-cli gdm3' instead. Report is attached.

[spi (spi-gmxpro)]

The apport report is attaches. Status still shows as incomplete. Is there anything else I can do to troubleshoot or provide logs?

[Launchpad Janitor (janitor)]

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

[spi (spi-gmxpro)]

Is there anything else I can provide to dig into this issue?

As this is really an annoying bug I disabled autofs completely and am trying systemd automounter instead again. Without further support by systemd units and NetworkManager dispatcher scripts, gdm3 hangs after suspend/resume when

- notebook on ethernet connection, network share automounted by systemd, notebook suspended, resumed without ethernet but wifi connection

and

- notebook on ethernet connection, network share automounted by systemd, notebook suspended, resumed without any network connection

Currently I am trying after-suspend.service and before-suspend.service units to unmount and remount shares (by stopping and starting the appropriate automount-systemd-services). As this is also needed when unplugging the notebook from ethernet without suspending/resuming it I also use a NetworkManager dispatcher script to stop/start the systemd automount-scripts when changes in the network setup are detected.

[Sebastien Bacher (seb128)]

It could help adding your 'journalctl -b <n>' from a session having the issue (n = 0 if you didn't restart the machine yet, 1 if you restarted once, etc)

You could also try reporting upstream directly to the concerned project on https://gitlab.gnome.org/GNOME/gdm/issues/

[spi (spi-gmxpro)]

Ok, filed a ticket upstream: https://gitlab.gnome.org/GNOME/gdm/-/issues/618

[spi (spi-gmxpro)]

I am still having this issue with another device on Ubuntu 20.04. From time to time the login screen freezes.

Usually my notebook is docked via USB-C to an external monitor and Ethernet-NIC, wifi stays on. My gdm3 login screen locks now and then when I undock my notebook and close the lid (or other way round). After opening the lid I neither can type in a password nor does fingerprint unlocking work.

I suspect network share automounter. Prior 20.04 I used autofs and these freezes happend very often. I changed the automount-scripts to detect my file server and things got better. With 20.04 I am using systemd to automount and things got even better. But still from time to time the login window just freezes. When I am still at home connected to my home wifi sometimes the login screen unfreezes after a couple of minutes - it looks like it needs some time for a timeout to hit.

If the freeze doesn't go away I switch to a terminal console and issue

  export DISPLAY=:0.0
  killall -3 gnome-shell

But very often that doesn't help anymore so I need to power down the notebook.

[spi (spi-gmxpro)]

After additional investigation I am not sure anymore that this is bound to systemd automount.
When gdm3 login screen freezes I can't enter a password - it is just frozen and doesn't accept any input anymore.

Is there any way to investigate that further? Logs, configs whatever?

[spi (spi-gmxpro)]

There are similar reports from other users as well, like
https://askubuntu.com/questions/1239073/ubuntu-20-04-lts-screen-freezes-after-login-when-waking-laptop-up-from-suspend/1423381#1423381
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1785964

I'd dig into that but do not know how to investigate it.