Login always ends in "Authentication failure" after laptop change

Ask Fedora
1

I changed laptop, but keep the same disk and now I can’t login.

My disk contains a dual boot Fedora 43 (main) / Pop OS.
At first my computer didn’t booted at all, but by manually booting Pop Os with grub, we (with a friend) were able to identify and fix the pr (Fedora couldn’t mount efi partition, so we commented it from fstab).

Now Fedora boots but I can’t log in. I can still login to Pop Os (although I still need to manually boot via grub).

I’ve already tried to:

  • login from the login manger (checking that the password was well written)
  • login from the tty (both as my user and root, after giving root a password)
  • change my passwords (by chroot-ing from Pop Os, using passwd, and checking the contents of /etc/shadows)
  • type my password (in su) while being chroot-ed
  • change my shell to /bin/bash
  • mount the /boot/efi partition from the chroot (with /proc, /sys and /dev mounted) and authentify (via su)

Every single attempt failed without giving more information than “Authentication failure”.

I don’t know if the problem is only software-based or if it has his roots in a hardware problem. I changed from a ~10yo HP Pavillon to a ~5yo Dell Inspiron, maybe a security chip is causing problems (when repairing it, I noticed a chip linked to the fingerprint reader). I must precise that secure boot is disabled, and that the previous owner of my computer was also a Fedora user, and that he tried and failed to make the fingerprint reader work. This could perfectly be a false lead.

I’m really looking forward for your help, because I don’t have any ideas left of how to fix this

2

In general, with previously used systems it is best to start with a fresh install so you can be confident that your system configuration matches what most other users will have.

3

Have you looked in the journal around the login failures ?

One way to do that is to edit the grub (fedora) entry and add on the linux line:

  • systemd.debug_shell
    This will gives you a root shell on tty9 (Ctrl-Alt-F9) without needing a password.

Boot and reproduce the login failure with your user name.
From tty9, execute for example: journalctl -b | grep -9 YOUR_USER_NAME

PS: Do not attempt any upgrade until /boot/efi is properly mounted because some
packages may need it.