Unable to login on virtual terminals: Entering username "auto-enters" blank passwords; gretty crashing

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frucade
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Unable to login on virtual terminals: Entering username "auto-enters" blank passwords; gretty crashing

Post by frucade »

After upgrading to LM19.1 I can no longer login via a virtual terminal. After pressing [Ctrl]-[Alt]-[F2] and entering my username "ben" it immediately enters a blank password, then repeats 4 times to display "Login incorrect" with an emtpy username, then finally claring & restarting gretty.

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$ journalctl -f
Feb 05 13:39:28 n223 login[16070]: pam_unix(login:auth): conversation failed
Feb 05 13:39:28 n223 login[16070]: pam_unix(login:auth): auth could not identify password for [ben]
Feb 05 13:39:32 n223 login[16070]: FAILED LOGIN (1) on '/dev/tty2' FOR 'ben', Authentication failure
Feb 05 13:39:32 n223 login[16070]: pam_securetty(login:auth): cannot determine username
Feb 05 13:39:36 n223 login[16070]: FAILED LOGIN (2) on '/dev/tty2' FOR 'UNKNOWN', Error in service module
Feb 05 13:39:36 n223 login[16070]: pam_securetty(login:auth): cannot determine username
Feb 05 13:39:39 n223 login[16070]: FAILED LOGIN (3) on '/dev/tty2' FOR 'UNKNOWN', Error in service module
Feb 05 13:40:28 n223 systemd[1]: getty@tty2.service: Service has no hold-off time, scheduling restart.
Feb 05 13:40:28 n223 systemd[1]: getty@tty2.service: Scheduled restart job, restart counter is at 6.
Feb 05 13:40:28 n223 systemd[1]: Stopped Getty on tty2.
Feb 05 13:40:28 n223 systemd[1]: Started Getty on tty2.
systemd config:

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$  systemctl cat --no-pager getty@tty2.service
#  SPDX-License-Identifier: LGPL-2.1+
#
#  This file is part of systemd.
#
#  systemd is free software; you can redistribute it and/or modify it
#  under the terms of the GNU Lesser General Public License as published by
#  the Free Software Foundation; either version 2.1 of the License, or
#  (at your option) any later version.

[Unit]
Description=Getty on %I
Documentation=man:agetty(8) man:systemd-getty-generator(8)
Documentation=http://0pointer.de/blog/projects/serial-console.html
After=systemd-user-sessions.service plymouth-quit-wait.service getty-pre.target
After=rc-local.service

# If additional gettys are spawned during boot then we should make
# sure that this is synchronized before getty.target, even though
# getty.target didn't actually pull it in.
Before=getty.target
IgnoreOnIsolate=yes

# IgnoreOnIsolate causes issues with sulogin, if someone isolates
# rescue.target or starts rescue.service from multi-user.target or
# graphical.target.
Conflicts=rescue.service
Before=rescue.service

# On systems without virtual consoles, don't start any getty. Note
# that serial gettys are covered by serial-getty@.service, not this
# unit.
ConditionPathExists=/dev/tty0

[Service]
# the VT is cleared by TTYVTDisallocate
# The '-o' option value tells agetty to replace 'login' arguments with an
# option to preserve environment (-p), followed by '--' for safety, and then
# the entered username.
ExecStart=-/sbin/agetty -o '-p -- \\u' --noclear %I $TERM
Type=idle
Restart=always
RestartSec=0
UtmpIdentifier=%I
TTYPath=/dev/%I
TTYReset=yes
TTYVHangup=yes
TTYVTDisallocate=yes
KillMode=process
IgnoreSIGPIPE=no
SendSIGHUP=yes

# Unset locale for the console getty since the console has problems
# displaying some internationalized messages.
UnsetEnvironment=LANG LANGUAGE LC_CTYPE LC_NUMERIC LC_TIME LC_COLLATE LC_MONETARY LC_MESSAGES LC_PAPER LC_NAME LC_ADDRESS LC_TELEPHONE LC_MEASUREMENT LC_IDENTIFICATION

[Install]
WantedBy=getty.target
DefaultInstance=tty1

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$ cat /etc/shells 
# /etc/shells: valid login shells
/bin/sh
/bin/dash
/bin/bash
/bin/rbash
/usr/local/bin/fish
/usr/bin/screen
/usr/bin/fish
/bin/csh

Code: Select all

$ cat /etc/passwd | grep ben
ben:x:1000:1000:ben,,,:/home/ben:/usr/bin/fish
Any ideas how to fix that?
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karlchen
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Re: Unable to login on virtual terminals: Entering username "auto-enters" blank passwords; gretty crashing

Post by karlchen »

Hello, frucade.

Your problem report reminds me of this recent thread:
Can't login to virtual terminals

This thread in turn is very likely about the same problem which had been reported end of January here:
Login via virtual console no longer works after latest kernel update

The issue seems to have been introduced when kernel K.4.15.0-43 (login on console tty's still working) was updated to K.4.15.0-44 (login on console tty's failing on some systems). The next kernel bugfix update K4.15.0-45 addressed two other problems, but not this one.

So in case your system runs on kernel 4.15.0-44 or 4.15.0-45, you might try returning to kernel 4.15.0-43 and see if you can log into the console tty's again.
Provided you can, you may be better off sticking to kernel K4.15.0-43 for the moment, till the issue will have been fixed some day.

You might also consider filing a bug report on Launchpad about the problem, thus bringing the problem to the Ubuntu developers' attention.

Best regards,
Karl
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frucade
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Re: Unable to login on virtual terminals: Entering username "auto-enters" blank passwords; gretty crashing

Post by frucade »

Wow!

Many thanks, karlchen. A little frustrating: I searched the forums prior to posting, but unfortunately did not hit the right search terms. So human brain seems to be still quite superiour.

Furthermore: You link exactly pinpoints the issue. The only difference is that I'm running the HWE-kernel 4.18.0-14-generic.

After downgrading to 4.18.0-13 and/or 4.15.0-43 my TTYs started to work again! I'll do a few searches on the issue to ensure that this bug has got the attention of the Ubuntu upstream.

Thank you very much! As you can see from my outputs I deeply assumed a misconfigured system, not a kernel issue. So your pointer helped me very much!
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Re: Unable to login on virtual terminals: Entering username "auto-enters" blank passwords; gretty crashing

Post by elviolmp »

I have followed the orientation to do the downgrade of version of kernel from 4.15.0-45 to 4.15.0-43 and now its working fine.
I will wait for new updates of the kernel.
Linux Mint 20 Cinnamon 64bits with AMD AM4 3600
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karlchen
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Re: Unable to login on virtual terminals: Entering username "auto-enters" blank passwords; gretty crashing

Post by karlchen »

Hello, elvioImp.

Do you have installed the software package gpm by any chance and enabled the service gpm.service, too? This might be one reason why logging in on the console monitors no longer works.
Seems gpm and kernels 4.15.0-44/45 and 4.4.0-142 do not get along with each other, whereas gpm and the previous kernel version 4.15.0-53 and 4.4.0-141 still did. Cf. Bug #1814261 gpm prevents loging to the console: spurious “Enter” events seems inserted.
On my Mint systems, gpm is not present (does not come pre-installed with Mint) and both kernels, K4.15.0-45 and K4.4.0-142, do not prevent me from logging in on the 6 console monitors.

Best regards,
Karl
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Haß gleicht einer Krankheit, dem Miserere, wo man vorne herausgibt, was eigentlich hinten wegsollte. (Goethe)
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Re: Unable to login on virtual terminals: Entering username "auto-enters" blank passwords; gretty crashing

Post by elviolmp »

karlchen wrote:
Thu Feb 07, 2019 12:35 pm
Hello, elvioImp.

Do you have installed the software package gpm by any chance and enabled the service gpm.service, too? This might be one reason why logging in on the console monitors no longer works.
Seems gpm and kernels 4.15.0-44/45 and 4.4.0-142 do not get along with each other, whereas gpm and the previous kernel version 4.15.0-53 and 4.4.0-141 still did. Cf. Bug #1814261 gpm prevents loging to the console: spurious “Enter” events seems inserted.
On my Mint systems, gpm is not present (does not come pre-installed with Mint) and both kernels, K4.15.0-45 and K4.4.0-142, do not prevent me from logging in on the 6 console monitors.

Best regards,
Karl
On my work computer, authenticating on a windows server domain, with the 4.15.0.45 kernel, I checked that I do not have gpm service installed.

Code: Select all

$systemctl list-units --type service --all | grep gpm
Nothing listed!

I have found the topics below about this case:
https://bugs.launchpad.net/ubuntu/+sour ... ug/1812095
https://bugs.launchpad.net/ubuntu/+sour ... ug/1813683


Thank you for the comments!
Elvio.
Linux Mint 20 Cinnamon 64bits with AMD AM4 3600
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karlchen
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Re: Unable to login on virtual terminals: Entering username "auto-enters" blank passwords; gretty crashing

Post by karlchen »

Hello, Elvio.

Thank you for this important information. So the bug does not only affect system where gpm is in use, but actually the scope is much wider. As I learnt from the 2 Launchpad bug reports to which you linked, the relevant bug report seems to be this one:
Bug #1813873 Userspace break as a result of missing patch backport

Hoping the Ubuntu guys will complete the incompletely bugfixed kernels really soon.

Best regards,
Karl
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Haß gleicht einer Krankheit, dem Miserere, wo man vorne herausgibt, was eigentlich hinten wegsollte. (Goethe)
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Re: Unable to login on virtual terminals: Entering username "auto-enters" blank passwords; gretty crashing

Post by BG405 »

Very interesting .. and a very serious bug IMHO. Not being able to log in to a TTY would have made it rather more difficult for me to fix various issues including a borked DE. I wonder if chroot still works OK in these cases?

Could auto-login have anything to do with this?
Dell Inspiron 1525 - LM17.3 CE 64-------------------Lenovo T440 8GB - Manjaro KDE with Mint VMs
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Acer Aspire E11 ES1-111M - LM18.2 KDE 64 ----Two ROMS don't make a WRITE ...
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Re: Unable to login on virtual terminals: Entering username "auto-enters" blank passwords; gretty crashing

Post by elviolmp »

BG405 wrote:
Fri Feb 08, 2019 11:07 am
Very interesting .. and a very serious bug IMHO. Not being able to log in to a TTY would have made it rather more difficult for me to fix various issues including a borked DE. I wonder if chroot still works OK in these cases?

Could auto-login have anything to do with this?
I wonder if chroot still works OK in these cases?
After downgrading the Kernel, on my production PC, I decided not to tamper implicate my tasks..

Could auto-login have anything to do with this?
I have not tested this alternative.
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Re: Unable to login on virtual terminals: Entering username "auto-enters" blank passwords; gretty crashing

Post by gm10 »

Ubuntu has recently fixed this in the 4.18 series. The fix for the 4.15 series is still in testing, will still be a week or two before you get that.

Code: Select all

linux (4.18.0-15.16) cosmic; urgency=medium

  * Ubuntu boot failure. 4.18.0-14 boot stalls. (does not boot) (LP: #1814555)
    - Revert "drm/i915/ringbuffer: Delay after EMIT_INVALIDATE for gen4/gen5"

  * Userspace break as a result of missing patch backport (LP: #1813873)
    - tty: Don't hold ldisc lock in tty_reopen() if ldisc present

 -- Stefan Bader <email address hidden> Thu, 07 Feb 2019 11:24:34 +0100
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Re: Unable to login on virtual terminals: Entering username "auto-enters" blank passwords; gretty crashing

Post by vwmoab »

This issue stil exists after todays kernel patch....as soon as i install Teamviewer after the patch the auto enter x 4 is there again.
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Re: Unable to login on virtual terminals: Entering username "auto-enters" blank passwords; gretty crashing

Post by gm10 »

vwmoab wrote:
Tue Mar 05, 2019 2:14 pm
This issue stil exists after todays kernel patch....as soon as i install Teamviewer after the patch the auto enter x 4 is there again.
Did you reboot yet? The fix is supposed to be in that kernel. Otherwise I suppose the fix wasn't a good one, but so far nobody had reported an issue with the fix: https://bugs.launchpad.net/ubuntu/+sour ... ug/1813873
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Re: Unable to login on virtual terminals: Entering username "auto-enters" blank passwords; gretty crashing

Post by vwmoab »

my bad!...i am so used to not having to reboot linux all the time....should have known a kernel patch would have required a reboot

all is working well now..sure glad thats fixed!
Thanks to all who made it so!!
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Re: Unable to login on virtual terminals: Entering username "auto-enters" blank passwords; gretty crashing

Post by elviolmp »

karlchen wrote:
Thu Feb 07, 2019 1:19 pm
Hello, Elvio.

Thank you for this important information. So the bug does not only affect system where gpm is in use, but actually the scope is much wider. As I learnt from the 2 Launchpad bug reports to which you linked, the relevant bug report seems to be this one:
Bug #1813873 Userspace break as a result of missing patch backport

Hoping the Ubuntu guys will complete the incompletely bugfixed kernels really soon.

Best regards,
Karl
Ok... kernel 4.15.0-46-generic - updated and solved problema!
:D
thank you very much.
Linux Mint 20 Cinnamon 64bits with AMD AM4 3600
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