Can't unlock Plasma lock screen (kscreenlocker) - "unlocking failed"

MightyPork · 2018-10-07 10:28:02

I'm unable to unlock my desktop on my home PC (with NVidia, if relevant). No matter what I enter, it says "unlocking failed", and I have to unlock using a TTY.
This is *not* that bug where it failed for all passwords after pressing Enter, it's something else - no need to press Enter, it's broken off the bat.

My work PC (Intel gfx) running a practically identical Arch setup doesn't have this problem. All packages are up to date.

extra/kscreenlocker 5.13.5-1 (plasma) [installed]

Here's a test that I hoped would reveal something:

~ $ /usr/lib/kscreenlocker_greet --testing
OpenGL vendor string:                   NVIDIA Corporation
OpenGL renderer string:                 GeForce GTX 960/PCIe/SSE2
OpenGL version string:                  4.6.0 NVIDIA 410.57
OpenGL shading language version string: 4.60 NVIDIA
Driver:                                 NVIDIA
Driver version:                         410.57
GPU class:                              Unknown
OpenGL version:                         4.6
GLSL version:                           4.60
Linux kernel version:                   4.18.12
Requires strict binding:                no
GLSL shaders:                           yes
Texture NPOT support:                   yes
Virtual Machine:                        no
Locked at 1538907919
UdevQt: unable to create udev monitor connection
Connecting to deprecated signal QDBusConnectionInterface::serviceOwnerChanged(QString,QString,QString)
file:///usr/share/plasma/look-and-feel/org.kde.breeze.desktop/contents/components/VirtualKeyboard.qml:20:1: module "QtQuick.VirtualKeyboard" is not installed
file:///usr/share/plasma/look-and-feel/org.kde.breeze.desktop/contents/components/VirtualKeyboard.qml:20:1: module "QtQuick.VirtualKeyboard" is not installed
QXcbClipboard: SelectionRequest too old
QXcbClipboard: SelectionRequest too old

Last edited by MightyPork (2018-10-07 10:30:11)

V1del · 2018-10-07 11:20:37

I've seen issues with that if people use a non image background. Do you use some of the fancier backgrounds like world map or so? Maybe also an incorrect session (though you probably wouldn't be able to unlock via TTY if that was the case) what's your output for

loginctl show-session $XDG_SESSION_ID

MightyPork · 2018-10-07 11:26:07

Background is the default it came with, some kind of abstract graphic, definitely an image.

screen: https://share.ondrovo.com/2018-10-07/Sc … 132226.png

here's the loginctl output

~ $ loginctl show-session $XDG_SESSION_ID
Id=2
User=1000
Name=ondra
Timestamp=Sun 2018-10-07 11:15:03 CEST
TimestampMonotonic=16922930
VTNr=1
Seat=seat0
Display=:0
Remote=no
Service=sddm
Desktop=KDE
Scope=session-2.scope
Leader=1799
Audit=2
Type=x11
Class=user
Active=yes
State=active
IdleHint=no
IdleSinceHint=0
IdleSinceHintMonotonic=0
LockedHint=no

Last edited by MightyPork (2018-10-07 16:28:25)

firekage · 2018-10-07 12:16:09

Sorry for posting in, but im curious - how are you able to unlock it with terminal, as you posted above?

V1del · 2018-10-07 13:16:47

looks alright, are you absolutely certain you've got the correct keyboard layout set (bottom left you can see what is being used) and aren't mistyping your password? Another thing that might be is some incorrect PAM setup, did you properly follow: https://www.archlinux.org/news/glibc-22 … ervention/ ?

FWIW I get the same output from a testing invocation, and everything works fine here.

Oh and maybe only post a link or switch to a thumbnail, that's a bit too big of a image. https://wiki.archlinux.org/index.php/Co … s_and_code

@firekage

loginctl unlock-session $SESSION_ID #Given above output as an example, would be 2

Last edited by V1del (2018-10-07 13:23:15)

MightyPork · 2018-10-07 16:33:43

@V1del keyboard is correct, I verified that by the "show password" button. None of that PAM newspost you linked applies to my setup, I remember looking for the pacnew and there wasn't any.

Someone elsewhere told me they solved this by fixing some bad file rights in systemd-logind (?), but that's all I got from them so I'm not any wiser.

The command I used was

sudo loginctl unlock-sessions

jagot · 2018-11-01 07:48:49

I had the same problem, you can test-drive it by from a terminal running

/usr/lib/kscreenlocker_greet --testing

which upon entering the correct password would print "Authentication failed" to the debug output.

The fix was to set proper SUID for /sbin/unix_chkpwd:

sudo chmod 4755 /sbin/unix_chkpwd

I found the solution here:
https://www.reddit.com/r/kde/comments/8 … =8&depth=9

MightyPork · 2018-11-01 21:03:19

@jagot tried your fix, but it didn't change anything in my case. reboot didn't do the trick either

jagot · 2018-11-02 15:45:18

@MightyPork Then I have no idea, sorry. Did you get "Authentication failed" as output from

/usr/lib/kscreenlocker_greet --testing

both before and after setting the SUID?

Arch Linux

#1 2018-10-07 10:28:02

Can't unlock Plasma lock screen (kscreenlocker) - "unlocking failed"

#2 2018-10-07 11:20:37

Re: Can't unlock Plasma lock screen (kscreenlocker) - "unlocking failed"

#3 2018-10-07 11:26:07

Re: Can't unlock Plasma lock screen (kscreenlocker) - "unlocking failed"

#4 2018-10-07 12:16:09

Re: Can't unlock Plasma lock screen (kscreenlocker) - "unlocking failed"

#5 2018-10-07 13:16:47

Re: Can't unlock Plasma lock screen (kscreenlocker) - "unlocking failed"

#6 2018-10-07 16:33:43

Re: Can't unlock Plasma lock screen (kscreenlocker) - "unlocking failed"

#7 2018-11-01 07:48:49

Re: Can't unlock Plasma lock screen (kscreenlocker) - "unlocking failed"

#8 2018-11-01 21:03:19

Re: Can't unlock Plasma lock screen (kscreenlocker) - "unlocking failed"

#9 2018-11-02 15:45:18

Re: Can't unlock Plasma lock screen (kscreenlocker) - "unlocking failed"

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