Hi Community,
when updating the kernel from 4.15.0-43 to 4.15.0-45, a fatal error occurs when logging in to the text console (multi-user target, Runlevel 3). After entering the login name (eg root) plus enter key, the cursor immediately moves on from the input prompt for the password, i. it sent an empty password for login. This is wrong and not correct.

The bug also occurs with kernel 4.18.0-14, which I have installed as a trial, affecting at least two kernel versions of it 4.15.0-45 and 4.18.0-14. The error does not occur if you want to log in as root after starting the KDE desktop with the console. So the last working kernel is 4.15.0-42.

The error does not occur if you want to log in as root after starting the KDE desktop with the console. Is the error already known neon or is there a bug report about it? What can you do that the login with the above mentioned kernel versions in the text console works again?
Distribution: KDE neon User Edition 5.14

Kernel : 4.15.0-45-generic
Plasma : 5.14.5
Qt : 5.11.2
KF : 5.54.0
Kwin : 5.14.5

regards
Michael

After logging in at the text-terminal's
command-line (before starting the graphical desktop),

try this:

$ ps $$
PID TTY STAT TIME COMMAND
16843 pts/3 Ss 0:00 -bash

If You get something with "sulogin" instead of
"bash", then You didn't reach "multi-user.target".

Report back.

Also, while still there, You could
enter (part between arrows):

==> systemctl | grep 'target .*' <==

and post the result.

NoNameNoBlame wrote:After logging in at the text-terminal's
command-line (before starting the graphical desktop),

In the "Grub" I temporarily entered the multi-user target (systemd.unit = multi-user.target) at the end of the line where the corresponding Linux kernel is entered.

I can not log in on the text console, because no password input is possible (see screenshot).
Screenshot: https://workupload.com/file/GvxBJue6

NoNameNoBlame wrote:try this:

$ ps $$
PID TTY STAT TIME COMMAND
16843 pts/3 Ss 0:00 -bash

If You get something with "sulogin" instead of
"bash", then You didn't reach "multi-user.target".

Report back.

Also, while still there, You could
enter (part between arrows):

==> systemctl | grep 'target .*' <==

and post the result.

As I said I can not log in, neither as root nor as a user in the text console (tty). The output of the command I created in the KDE console as root.

Code: Select all

# systemctl | grep 'target .*'
basic.target                                                                                               loaded active active    Basic System                                                                 
cryptsetup.target                                                                                          loaded active active    Local Encrypted Volumes                                                     
getty.target                                                                                               loaded active active    Login Prompts                                                               
graphical.target                                                                                           loaded active active    Graphical Interface                                                         
local-fs-pre.target                                                                                        loaded active active    Local File Systems (Pre)                                                     
local-fs.target                                                                                            loaded active active    Local File Systems                                                           
multi-user.target                                                                                          loaded active active    Multi-User System                                                           
network-online.target                                                                                      loaded active active    Network is Online                                                           
network.target                                                                                             loaded active active    Network                                                                     
nfs-client.target                                                                                          loaded active active    NFS client services                                                         
nss-lookup.target                                                                                          loaded active active    Host and Network Name Lookups                                               
nss-user-lookup.target                                                                                     loaded active active    User and Group Name Lookups                                                 
paths.target                                                                                               loaded active active    Paths                                                                       
remote-fs-pre.target                                                                                       loaded active active    Remote File Systems (Pre)                                                   
remote-fs.target                                                                                           loaded active active    Remote File Systems                                                         
rpcbind.target                                                                                             loaded active active    RPC Port Mapper                                                             
slices.target                                                                                              loaded active active    Slices                                                                       
sockets.target                                                                                             loaded active active    Sockets                                                                     
sound.target                                                                                               loaded active active    Sound Card                                                                   
swap.target                                                                                                loaded active active    Swap                                                                         
sysinit.target                                                                                             loaded active active    System Initialization                                                       
time-sync.target                                                                                           loaded active active    System Time Synchronized                                                     
timers.target


EDIT: my default target

Code: Select all

# systemctl get-default
graphical.target


Viewing Your picture requires JavaScript.
I won't allow it.

The WebSite states:

IV. Legal notice

Every visitor to the website can be traced via the Provider and can thus be …

Whatever that may mean. Don't want to be tracked.

---

You wrote:

the cursor immediately moves on from the input prompt for the password, i. it sent an empty password for login.

I ask:

Where does the text-cursor move to?
Asking for account-name, again? Something else?

Is there some output in the logs ("journalctl -b")?
Search for "login" or "tty" or for the useraccount-name
You did enter ("root"/<whatever>).

Did You try to simply enter nothing at all, just
pressing ENTER once or twice?

Hi NoNameNoBlame,

I ask:

Where does the text-cursor move to?
Asking for account-name, again? Something else?

The cursor moves to enter the password, but jumps immediately. The error message "Login incorrect" appears four times. Then the erroneous login messages are cleared on the screen and it starts all over again.

Is there some output in the logs ("journalctl -b")?
Search for "login" or "tty" or for the useraccount-name
You did enter ("root"/<whatever>).

Here the output from journalctl.

Code: Select all

# journalctl -b|egrep -i '(tty|login)'
Feb 03 12:47:13 neonlight login[9343]: pam_unix(login:auth): conversation failed
Feb 03 12:47:13 neonlight login[9343]: pam_unix(login:auth): auth could not identify password for [root]
Feb 03 12:47:16 neonlight login[9343]: FAILED LOGIN (1) on '/dev/tty2' FOR 'root', Authentication failure
Feb 03 12:47:17 neonlight login[9343]: pam_securetty(login:auth): cannot determine username
Feb 03 12:47:21 neonlight login[9343]: FAILED LOGIN (2) on '/dev/tty2' FOR 'UNKNOWN', Error in service module
Feb 03 12:47:21 neonlight login[9343]: pam_securetty(login:auth): cannot determine username
Feb 03 12:47:24 neonlight login[9343]: FAILED LOGIN (3) on '/dev/tty2' FOR 'UNKNOWN', Error in service module
Feb 03 12:47:25 neonlight login[9343]: pam_securetty(login:auth): cannot determine username
Feb 03 12:47:27 neonlight login[9343]: FAILED LOGIN (4) on '/dev/tty2' FOR 'UNKNOWN', Error in service module
Feb 03 12:47:29 neonlight login[9343]: pam_securetty(login:auth): cannot determine username
Feb 03 12:47:33 neonlight login[9343]: FAILED LOGIN (5) on '/dev/tty2' FOR 'UNKNOWN', Error in service module
Feb 03 12:47:33 neonlight login[9343]: TOO MANY LOGIN TRIES (5) on '/dev/tty2' FOR 'UNKNOWN'
Feb 03 12:47:33 neonlight login[9343]: pam_mail(login:session): cannot determine username
Feb 03 12:47:33 neonlight login[9343]: pam_unix(login:session): close_session - error recovering username
Feb 03 12:47:33 neonlight systemd[1]: getty@tty2.service: Service has no hold-off time, scheduling restart.
Feb 03 12:47:33 neonlight systemd[1]: getty@tty2.service: Scheduled restart job, restart counter is at 4.
Feb 03 12:47:33 neonlight systemd[1]: Stopped Getty on tty2.
Feb 03 12:47:33 neonlight systemd[1]: Started Getty on tty2.


Did You try to simply enter nothing at all, just
pressing ENTER once or twice?

It does not matter if I try something or nothing at all. The result is always the same "Login incorrect". The input cursor jumps immediately without waiting for my input.

Do this:

$ sudo cat /etc/shadow | grep root
root:!:17045:0:99999:7:::

If there is an exclamation point ('!'),
then Your "root"-account is intentionally
configured to not be able to be used for login.


It could only be used by emergency.target
(and/or maybe rescue.target - can't remember)

And then it wouldn't require a password,

because Mister Poettering of systemd-fame
decided to do it like this,
because <only the Gods know> or <not even the Gods know>.

NoNameNoBlame wrote:Do this:

$ sudo cat /etc/shadow | grep root
root:!:17045:0:99999:7:::

If there is an exclamation point ('!'),
then Your "root"-account is intentionally
configured to not be able to be used for login.

no there is no exclamation mark on the root account. It is neither a login with root nor with a user possible (both with the same error).

It could only be used by emergency.target
(and/or maybe rescue.target - can't remember)

And then it wouldn't require a password,

because Mister Poettering of systemd-fame
decided to do it like this,
because <only the Gods know> or <not even the Gods know>.

File-Permissions?

Code: Select all

$ TZ=UTC ls -l /etc/{shadow,passwd}
1 -rw-r--r-- 1 root root   1 2019-01-03T02:34:03+0000 /etc/passwd
1 -rw-r----- 1 root shadow 1 2019-01-03T02:34:03+0000 /etc/shadow


Edit:

Lock-files (*.lck)?

$ TZ=UTC ls /etc/{shadow,passwd}*[Ll]*

If nothing else helps, You could
add "debug" to these.

But if You do,
before rebooting, test it by logging in!!!
Use "su"-command. Afterwards: "journalctl -b", again.

Else: If typo, then worse than before.

Code: Select all

$ cat /etc/pam.d/login | grep -C1 ^auth
# to disable any delay, you should add the nodelay option to pam_unix)
auth       optional   pam_faildelay.so  delay=3000000

--
# communicated over insecure lines.
auth [success=ok new_authtok_reqd=ok ignore=ignore user_unknown=bad default=die] pam_securetty.so

--
# (Replaces the `NOLOGINS_FILE' option from login.defs)
auth       requisite  pam_nologin.so

--
# (Replaces the `CONSOLE_GROUPS' option in login.defs)
auth       optional   pam_group.so



You wrote:
error message "Login incorrect" appears four times.

Your journal-log:
systemd[1]: getty@tty2.service: Scheduled restart job, restart counter is at 4.

I say:
Both "4 times": Coincidence? Hardly.
Therefore:

Raise log-verbosity of "getty@.service"-TemplateUnit.

Hi NoNameNoBlame,

I am not alone with this bug
See here https://bugs.launchpad.net/ubuntu/+sour ... ug/1812095
....and here https://bugs.launchpad.net/ubuntu/+sour ... ug/1813683

This is probably a known bug in the kernel.

I agree 100%.

We have to wait for Ubuntu-Fix.

Thanks NoNameNoBlame for your help

Do you have a grub menu and a selection of an older version of the kernel? If you do not, think it is a solution boot the system is in recovery mode, login as root and install some mainline kernel eg. 4.19 or 4.20

I can confirm I'm getting the same issue.
Logging in with Plasma's user interface is working just fine.
However, whenever I switch to another terminal-only screens (Ctrl+Alt+F2 and so on), after pressing ENTER after typing in my username in the username prompt, it will somehow keep on sending more ENTER to the input on a loop, so I can't type in my password since it will forcefully submit the empty password prompt.
After it fails to login, it will of course show another login prompt to try again, but this time I won't even be able to input my username since it will forcefully submit the empty username prompt. And as we know it, empty username will fail too.
So yeah, it will keep on doing that until the maximum 4 tries, after which the screen will just "reset", and I will end up with the same issue all over again if I try to login.

EDIT: Someone mentioned being unwilling to view the screenshot from one of the previous replies.
Here it is re-uploaded somewhere else:

Pretty much the same thing I'm seeing.

EDIT 2: Trying to login as root or not appears to be irrelevant, as I'm getting the issue when trying to login to my own non-root account.