Bug#1119987: kde-plasma-desktop: On Debian 13 the screen locker (kscreenlocker_greet) periodically fails to unlock.
Package: kde-plasma-desktop
Version: 5:162
Severity: normal
X-Debbugs-Cc: mbkoras@gmail.com
Dear Maintainer,
On a fresh Debian 13 (Trixie) installation with KDE Plasma 6 (x11),
the screen locker (kscreenlocker_greet) periodically fails to unlock
when the pam_sss.so module is missing.
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 by default) seems to fixe 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 — the greeter accepts input but does not respond or remains frozen.
--- Expected Behavior ---
The lock screen should always unlock normally with password entry
--- Actual Behavior ---
The greeter sometimes becomes unresponsive and fails to unlock.
--- Workaround ---
Installing `libpam-sss` resolves the problem:
sudo apt install libpam-sss
--- System Information ---
- Plasma: 6.x (from Debian Trixie)
- Session: X11
- GPU: NVIDIA proprietary driver
- Kernel: 6.12.48+deb13-amd64
-- System Information:
Debian Release: 13.1
APT prefers stable-updates
APT policy: (500, 'stable-updates'), (500, 'stable-security'), (500, 'stable')
Architecture: amd64 (x86_64)
Kernel: Linux 6.12.48+deb13-amd64 (SMP w/8 CPU threads; PREEMPT)
Kernel taint flags: TAINT_PROPRIETARY_MODULE, TAINT_OOT_MODULE, TAINT_UNSIGNED_MODULE
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE=en_US:en
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled
Versions of packages kde-plasma-desktop depends on:
ii kde-baseapps 4:24.12.0+5.162
ii plasma-desktop 4:6.3.6-1
ii plasma-workspace 4:6.3.6-2
ii udisks2 2.10.1-12.1+deb13u1
ii upower 1.90.9-1
Versions of packages kde-plasma-desktop recommends:
ii kde-inotify-survey 25.04.0-1
ii kwin-x11 4:6.3.6-1
ii libpam-fprintd 1.94.5-2
ii sddm 0.21.0+git20250502.4fe234b-2
ii webext-plasma-browser-integration 6.3.4-2
ii xserver-xorg 1:7.7+24
Versions of packages kde-plasma-desktop suggests:
ii kdeconnect 25.04.2-1
-- no debconf information
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