Upgraded kernel to linux-image-4.18.0-14.15-generic 4.18.20, and discovered I can no longer log into a local console

[PhotonQyv]

When I attempt to log into a local (Getty) console, having entered my username, the password prompt appears but then the cursor moves to the next line as I'm typing the password, and the log in times out with a 'Login incorrect' message, then the console prompt loops, displaying '[machine-name] login', followed by 'Login incorrect', until systemd restarts the service for that console.

With the previous kernel, i.e. 4.18.0-13.14-generic the login process works fine.

This wouldn't normally bother me, as I don't tend to use the local consoles for much, I just noticed it when I wanted to use one to check that something else was working correctly.

I've currently set my GRUB config to boot the old 4.18.0-13.14-generic kernel, as a work-around.

ProblemType: Bug
DistroRelease: Ubuntu 18.10
Package: linux-image-4.18.0-14-generic 4.18.0-14.15
ProcVersionSignature: Ubuntu 4.18.0-14.15-generic 4.18.20
Uname: Linux 4.18.0-14-generic x86_64
ApportVersion: 2.20.10-0ubuntu13.1
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC1: qyv 3428 F.... pulseaudio
 /dev/snd/controlC0: qyv 3428 F.... pulseaudio
CurrentDesktop: KDE
Date: Mon Jan 21 14:37:03 2019
HibernationDevice: RESUME=/swapfile
InstallationDate: Installed on 2018-04-10 (286 days ago)
InstallationMedia: Kubuntu 18.04 LTS "Bionic Beaver" - Beta amd64 (20180404)
MachineType: Hewlett-Packard HP Pavilion g6 Notebook PC
ProcFB: 0 radeondrmfb
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-4.18.0-14-generic root=/dev/mapper/kubuntu--vg-root ro quiet splash vt.handoff=1
RelatedPackageVersions:
 linux-restricted-modules-4.18.0-14-generic N/A
 linux-backports-modules-4.18.0-14-generic N/A
 linux-firmware 1.175.1
RfKill:
 0: phy0: Wireless LAN
  Soft blocked: no
  Hard blocked: no
SourcePackage: linux
UpgradeStatus: Upgraded to cosmic on 2018-10-19 (93 days ago)
dmi.bios.date: 05/13/2013
dmi.bios.vendor: Insyde
dmi.bios.version: F.6A
dmi.board.asset.tag: Base Board Asset Tag
dmi.board.name: 3566
dmi.board.vendor: Hewlett-Packard
dmi.board.version: 21.46
dmi.chassis.type: 10
dmi.chassis.vendor: Hewlett-Packard
dmi.chassis.version: Chassis Version
dmi.modalias: dmi:bvnInsyde:bvrF.6A:bd05/13/2013:svnHewlett-Packard:pnHPPaviliong6NotebookPC:pvr068F130000204710000620100:rvnHewlett-Packard:rn3566:rvr21.46:cvnHewlett-Packard:ct10:cvrChassisVersion:
dmi.product.family: 103C_5335KV G=N L=CON B=HP S=PAV
dmi.product.name: HP Pavilion g6 Notebook PC
dmi.product.sku: B6G97EA#ABU
dmi.product.version: 068F130000204710000620100
dmi.sys.vendor: Hewlett-Packard

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This change was made by a bot.

[Benjamin Schmid (benbuntu)]

I can confirm, that this regression affects 4.18.0-15 as well as 4.15.0-44. After downgrading to 4.18.0-14 terminals start to work again for me.

This is the relevant log output:

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

Related forum entries of me/others having this problem:

https://forums.linuxmint.com/viewtopic.php?f=47&t=287366
https://forums.linuxmint.com/viewtopic.php?f=18&t=286798