Bug 511577

Summary:	On a fresh Debian 13 (Trixie) installation with KDE Plasma 6 (x11), the screen locker (kscreenlocker_greet) periodically fails to unlock.
Product:	[Plasma] plasmashell	Reporter:	Marios Korras Carraca <mbkoras>
Component:	Screen locking	Assignee:	Plasma Bugs List <plasma-bugs-null>
Status:	RESOLVED UNMAINTAINED
Severity:	normal	CC:	mbkoras
Priority:	NOR
Version First Reported In:	6.3.6
Target Milestone:	1.0
Platform:	Debian stable
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description Marios Korras Carraca 2025-11-03 15:17:30 UTC

Each time the session locks, the journal shows:

PAM unable to dlopen(pam_sss.so): /usr/lib/security/pam_sss.so: cannot open shared object file: No such file or directory
PAM adding faulty module: pam_sss.so

Sometimes the lock screen remains frozen or completely unresponsive to password input.
Installing libpam-sss (not-preinstalled in my system) seems to fix the issue.

Steps to Reproduce:

1) Install Debian 13 (Trixie) with KDE Plasma (no libpam-sss installed).

2) Boot normally and log into a Plasma session (x11).

3) Lock the screen

4) Attempt to unlock — sometimes the greeter accepts input but does not respond, or remains frozen.

journalctl -b | grep pam_sss
 PAM unable to dlopen(pam_sss.so): /usr/lib/security/pam_sss.so: cannot open shared object file: No such file or directory
PAM adding faulty module: pam_sss.so

Installing libpam-sss seems to correct (for now) the problem.

Comment 1 Bug Janitor Service 2025-11-03 15:33:41 UTC

Thank you for the bug report!

Debian advises users to not submit bugs upstream (https://www.debian.org/Bugs/Reporting), and Plasma 6.3.6 is no longer eligible for support or maintenance from KDE. It's possible that the issue exists only in Debian at this point.

Could you report the bug to Debian using the report bug utility (https://packages.debian.org/stable/utils/reportbug)? If necessary, the maintainer of the package will forward the bug upstream.
Thanks for understanding!

Thanks again!

Comment 2 Marios Korras Carraca 2025-11-03 17:02:14 UTC

(In reply to Bug Janitor Service from comment #1)
> Thank you for the bug report!
> 
> Debian advises users to not submit bugs upstream
> (https://www.debian.org/Bugs/Reporting), and Plasma 6.3.6 is no longer
> eligible for support or maintenance from KDE. It's possible that the issue
> exists only in Debian at this point.
> 
> Could you report the bug to Debian using the report bug utility
> (https://packages.debian.org/stable/utils/reportbug)? If necessary, the
> maintainer of the package will forward the bug upstream.
> Thanks for understanding!
> 
> Thanks again!

Thank you for the follow-up!

I have reported the issue to Debian as suggested.
It has been filed as bug #1119987:

Best regards
M.K.K