[SOLVED] Logins fail once multi-user.target is reached

akraut · 2023-04-03 18:59:07

Hey folks,
Something unknown happened during my last `pacman -Syu` which locked me out of my system. Unfortunately, my screen timed out and locked in the middle. I was then no longer able to unlock it. It kept saying my password was incorrect and wouldn't read my fingerprint. I can boot up in rescue mode and have been digging it, but making no progress. This smells like a pam issue, but after resetting everything in /etc/pam.d to defaults by reinstalling and overwriting, I'm still no closer to a working login.

Symptoms:

Failed logins (with known-good passwords and known-unlocked accounts for both root and user accounts) at a text console and via GDM.
GDM no longer has a user-picker; it just prompts for a username.
Root password works for rescue console, but doesn't work once multi-user.target is reached.

Stuff I've tried:

Resetting system-* pam configs to default-installed. (The only changes I had made there were to add pam_fprintd_grosshack.so to system-auth's auth section.)
Moving pam_systemd_home.so out of /usr/lib/security

Logs and things:

Journalctl sample of a session where logins fail on tty console: https://0x0.st/HHnU.txt
Pacman reporting on changed files in /etc/pam.d/*: http://0x0.st/HHU-.txt (This was before I reinstalled pambase.)

Any ideas where things went sideways?

Update: Solved. Zero-byte-size /etc/shells was restored to defaults.

Last edited by akraut (2023-04-04 05:22:36)

seth · 2023-04-03 19:26:25

There's no pam error recorded (homed doesn't count), only

Apr 03 11:11:30 framework-c001e57 login[756]: FAILED LOGIN 1 FROM tty1 FOR akraut, Authentication failure
Apr 03 11:11:36 framework-c001e57 login[756]: FAILED LOGIN 2 FROM tty1 FOR root, Authentication failure

Is /etc/pam.d/system-auth back to the default one?

Other than that you're using NM and systemd-networkd concurrently what *can* cause such issues and *will* generally cause others.
Pick one, disable the other.

Edit, also

Apr 03 11:11:05 framework-c001e57 avahi-daemon[702]: *** WARNING: Detected another IPv4 mDNS stack running on this host. This makes mDNS unreliable and is thus not recommended. ***
Apr 03 11:11:05 framework-c001e57 avahi-daemon[702]: *** WARNING: Detected another IPv6 mDNS stack running on this host. This makes mDNS unreliable and is thus not recommended. ***
…
Apr 03 11:11:14 framework-c001e57 avahi-daemon[702]: Host name conflict, retrying with framework-c001e57-2

The hostname conflict might be down to IPv4/6, but the systemd-resolved mdns stack seems active as well.

Last edited by seth (2023-04-03 19:35:11)

akraut · 2023-04-03 22:59:46

/etc/pam.d/system-auth is currently the default one. I've disabled systemd-networkd and systemd-resolved, but still no joy. I still get no errors (or the same only errors about homed) from pam.

akraut · 2023-04-04 05:21:59

OMG. Now that I've thoroughly pulled my hair out... I reinstalled the default /etc/shells which I found was blank.

I literally sat, staring at the ls in /etc to figure out what had changed and that 0 filesize stared back for quite a while before I noticed it. I'm still at a loss at how that file got truncated. Maybe I fubar'd a pacdiff?

Thanks for the help!

Arch Linux

#1 2023-04-03 18:59:07

[SOLVED] Logins fail once multi-user.target is reached

#2 2023-04-03 19:26:25

Re: [SOLVED] Logins fail once multi-user.target is reached

#3 2023-04-03 22:59:46

Re: [SOLVED] Logins fail once multi-user.target is reached

#4 2023-04-04 05:21:59

Re: [SOLVED] Logins fail once multi-user.target is reached

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