GDM fails to log me in

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Hi everyone,
I have a Fedora stick running F43 Workstation with the GNOME desktop. I have installed the GNOME, GNOME Classic and Phosh sessions. Now, after about a month or so I booted from that stick. At first, systemctl was stuck on dev-sda2 mount, but that was fixed. A reboot and it worked. So I was now on the GDM3 login screen. I selected myself, and enter my passcode. When I press Enter to log me in, a mouse showed up, and then the screen went black until I was brought back to GDM. Luckily, I could access a TTY and view what systemctl had to say about this:

â—Ź gdm.service - GNOME Display Manager
     Loaded: loaded (/usr/lib/systemd/system/gdm.service; enabled; preset: enabled)
    Drop-In: /usr/lib/systemd/system/service.d
             └─10-timeout-abort.conf
     Active: active (running) since Fri 2026-02-27 01:00:19 CET; 1 month 9 days ago
 Invocation: 4e37afe82d69434c882cd586b12a3a2f
   Main PID: 1226 (gdm)
      Tasks: 9 (limit: 18864)
     Memory: 10.8M (peak: 28.9M)
        CPU: 1.831s
     CGroup: /system.slice/gdm.service
             ├─1226 /usr/bin/gdm
             └─5200 "gdm-session-worker [pam/gdm-password]"

Apr 07 18:07:55 fedora-linux-laptop gdm-password][56956]: pam_unix(gdm-password:auth): authentication failure; logname= uid=0 euid=0 tty=/dev/tty1 ruser= rh>
Apr 07 18:07:55 fedora-linux-laptop gdm-password][56956]: gkr-pam: unable to locate daemon control file
Apr 07 18:07:55 fedora-linux-laptop gdm-password][56956]: gkr-pam: stashed password to try later in open session
Apr 07 18:08:02 fedora-linux-laptop gdm-password][57015]: gkr-pam: unable to locate daemon control file
Apr 07 18:08:02 fedora-linux-laptop gdm-password][57015]: gkr-pam: stashed password to try later in open session
Apr 07 18:08:46 fedora-linux-laptop gdm-password][57252]: pam_unix(gdm-password:auth): authentication failure; logname= uid=0 euid=0 tty=/dev/tty1 ruser= rh>
Apr 07 18:08:46 fedora-linux-laptop gdm-password][57252]: gkr-pam: unable to locate daemon control file
Apr 07 18:08:46 fedora-linux-laptop gdm-password][57252]: gkr-pam: stashed password to try later in open session
Apr 07 18:08:52 fedora-linux-laptop gdm-password][57261]: gkr-pam: unable to locate daemon control file
Apr 07 18:08:52 fedora-linux-laptop gdm-password][57261]: gkr-pam: stashed password to try later in open session
lines 1-24/24 (END)

I’ve tried to restart the GDM process multiple times and changed the PAM config multiple times, but that didn’t help.
Is there any other known solution?
My system is up to date and I’ve tried reinstalling GDM, gnome-session (yes, that also doesn’t work:

** Message: 19:09:58.716: Starting GNOME session target: gnome-session-tty@gnome.target

** (process:58905): ERROR **: 19:09:58.717: Failed to start unit gnome-session-tty@gnome.target: GDBus.Error:org.freedesktop.systemd1.NoSuchUnit: Unit gnome-session-tty@gnome.target not found.
Trace/Breakpoint ausgelöst(Speicherabzug geschrieben) gnome-session

), Wayland and GNOME Shell multiple times.
Thanks

1 Like
2

Turn GDM off and boot to a console tty. Login there Ă nd start gnome with startx
The easiest way to disable GDM is to rename its binary.

Black screen usually indicates failure of X11 or Wayland to start. Can also be problems with logind.

1 Like
3

Fedora has disabled and removed all their GNOME X11 sessions, so that sadly doesn’t work either.
I think that applies to GNOME in general.

1 Like
4

Ok, so I replaced GDM with LightDM. The result is the same…

1 Like
5

Do you need a greeter? Start the Wayland session from tty after you have logged in.

Check the link part “2.2 Manually” (it starts with xorg but keep reading) :

1 Like
6

Thanks for that, but it still doesn’t want after that.

EDIT: Seems like it worked after gnome-shell --wayland, but I read that’s not recommended and my setup is somehow broken (extensions not loading, defaults to a half broken GNOME Flashback)

2 Likes
7

Take a backup of your home folder and maybe configs (dot files) and do a fresh install?

1 Like
8

Ok, I think I solved it. After the gnome-session and a reboot, for some reason, it works (apart from asking me to unlock keychain after every siginin…, but that’s life :wink:)

3 Likes
9

Because the fault is not in the login manager, it is failing to start the Xserver ( or Wayland whatever)

1 Like
10

Is this same as keyring? Check the arch wiki GNOME/Keyring - ArchWiki There’s

When using a display manager, the keyring works out of the box for most cases. GDM, LightDM, LXDM, and SDDM already have the necessary PAM configuration. For a display manager that does not automatically unlock the keyring edit the appropriate file instead of /etc/pam.d/login as mentioned below.

And the etc/pam.d/login

/etc/pam.d/login

#%PAM-1.0

auth required pam_securetty.so
auth requisite pam_nologin.so
auth include system-local-login
auth optional pam_gnome_keyring.so
account include system-local-login
session include system-local-login
session optional pam_gnome_keyring.so auto_start

I personally don’t like gnome but found a lot of info from Arch wiki.

3 Likes
11

Aha, but I think these are Arch-related? My PAM looks like this:

   1 │ #%PAM-1.0
   2 │ auth       substack     system-auth
   3 │ auth       include      postlogin
   4 │ account    required     pam_nologin.so
   5 │ account    include      system-auth
   6 │ password   include      system-auth
   7 │ # pam_selinux.so close should be the first session rule
   8 │ session    required     pam_selinux.so close
   9 │ session    required     pam_loginuid.so
  10 │ # pam_selinux.so open should only be followed by sessions to be executed in the user context
  11 │ session    required     pam_selinux.so open
  12 │ session    required     pam_namespace.so
  13 │ session    optional     pam_keyinit.so force revoke
  14 │ session    include      system-auth
  15 │ session    include      postlogin
  16 │ -session   optional     pam_ck_connector.so
1 Like
12

Yes, I used Arch wiki because it’s all SystemD. Here’s what Fedora’s wiki says: QA-L10N:gnome-keyring - Fedora Project Wiki Not useful. Here’s some info on Gentoo’s wiki about the black screen on wayland: https://wiki.gentoo.org/wiki/GNOME/GDM#GDM_crashes_when_attempting_to_launch_a_GNOME_Wayland_session

3 Likes