Bug 508660 - Nobara Fedora Linux derivative-kscreenlocker_greet hangs computer completely when trying to switch user.
Summary: Nobara Fedora Linux derivative-kscreenlocker_greet hangs computer completely ...
Status: REOPENED
Alias: None
Product: plasmashell
Classification: Plasma
Component: Screen locking (other bugs)
Version First Reported In: 6.4.3
Platform: Other Linux
: NOR normal
Target Milestone: 1.0
Assignee: Plasma Bugs List
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2025-08-23 21:10 UTC by Mik
Modified: 2025-08-28 20:10 UTC (History)
4 users (show)

See Also:
Latest Commit:
Version Fixed/Implemented In:
Sentry Crash Report:


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Description Mik 2025-08-23 21:10:09 UTC
***
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***

SUMMARY


STEPS TO REPRODUCE
1.  lock screen after login.
2. click on switch user
3. hard reset computer to get back into OS.

OBSERVED RESULT
Complete computer hang. Graphical KDS hangs. No ability to CTRL-Fx to get to a cli. Have to hard reset to get back into OS.

EXPECTED RESULT
Switch user should list users allowing the selection of a user to enter their password and to login.

Note: If I login and then logout and then login again, I can lock the screen and click on switch user without isse.

SOFTWARE/OS VERSIONS
(available in the Info Center app, or by running `kinfo` in a terminal window)
kinfo
pci id for fd 16: 10de:25a2, driver (null)
pci id for fd 17: 10de:25a2, driver (null)
Operating System: Nobara Linux 42
KDE Plasma Version: 6.4.3
KDE Frameworks Version: 6.16.0
Qt Version: 6.9.1
Kernel Version: 6.16.2-200.nobara.fc42.x86_64 (64-bit)
Graphics Platform: Wayland
Processors: 12 × AMD Ryzen 5 5600H with Radeon Graphics
Memory: 16 GiB of RAM (15.0 GiB usable)
Graphics Processor 1: AMD Radeon Graphics
Graphics Processor 2: NVIDIA GeForce RTX 3050 Laptop GPU

ADDITIONAL INFORMATION
Submitted to Reddit KDE.
https://www.reddit.com/r/kde/comments/1mycewe/switch_user_hangs_hard_reset_needed/?utm_source=share&utm_medium=web3x&utm_name=web3xcss&utm_term=1&utm_content=share_button
Comment 1 David Edmundson 2025-08-23 21:27:43 UTC
Can you provide output of:
`loginctl list-sessions` after login

files in:
/usr/lib/sddm/sddm.conf.d/*
/etc/sddm/sddm.conf
/etc/sddm/sddm.conf.d/*


Then reset this ticket's status to unconfirmed
Comment 2 Mik 2025-08-23 23:07:40 UTC
sudo loginctl list-sessions
[sudo] password for miklove: 
SESSION  UID USER    SEAT  LEADER CLASS         TTY   IDLE SINCE
      1 1000 miklove -     1743   manager       -     no   -    
      2 1000 miklove seat0 1765   user          tty1  no   -    
      5    0 root    -     14465  manager-early -     no   -    
     c3 1000 miklove -     2832   background    -     no   -    
     c6    0 root    -     13898  user-early    pts/1 no   -    

5 sessions listed.
Comment 3 Mik 2025-08-23 23:10:22 UTC
Status Unconfirmed is not available as a status.
Comment 4 Mik 2025-08-24 06:44:38 UTC
as per my reply in reddit......

I dont seem to be able to edit my original post so just to add a little more info.

I added another user, no initial difference to issue. Only I as a user show up in the locker screen.

It is kscreenlocker_greet that is the screen locker program.

If I logout and login, and then lock, switch user now works but only current user shows up, but at least it doesn't hang the whole computer now if I accidentally click on switch users, and I can login again.

Updated script to wait 15secs, logout, and with autologin enabled, it automatically loges in agan as me, and then locks the screen after another 15seconds.

I dont seem to be able to edit my original post so just to add a little more info.

I added another user, no initial difference to issue. Only I as a user show up in the locker screen.

It is kscreenlocker_greet that is the screen locker program.

If I logout and login, and then lock, switch user now works but only current user shows up, but at least it doesn't hang the whole computer now if I accidentally click on switch users, and I can login again.

Updated script to wait 15secs, logout, and with autologin enabled, it automatically loges in agan as me, and then locks the screen after another 15seconds.

#!/usr/bin/python
import tkinter as tk
from tkinter import filedialog, messagebox
from pathlib import Path
import threading
import time
import os

# Start countdown
def start_countdown():
    try:
        minutes = 0
        seconds = 14
        total_seconds = minutes * 60 + seconds
        if total_seconds <= 0:
            messagebox.showerror("Error", "Please enter a positive time.")
            return
    except ValueError:
        messagebox.showerror("Error", "Please enter valid numbers.")
        return
    threading.Thread(target=run_countdown, args=(total_seconds,), daemon=True).start()

# Run countdown in background
def run_countdown(total_seconds):
    while total_seconds > 0:
        total_seconds -= 1
        mins = total_seconds // 60
        secs = total_seconds % 60
        countdown_label.config(text=f"{mins:02d}:{secs:02d}")
        time.sleep(1)
    if not a.exists():
        with open('/tmp/flag_file', 'w') as f:
            pass
        root.quit()
        os.system("qdbus org.kde.Shutdown /Shutdown logout")
        root.destroy()
    else:
        os.remove(a)
        root.quit()
        os.system("qdbus org.freedesktop.ScreenSaver /ScreenSaver Lock")
        root.destroy()


# GUI setup
a = Path("/tmp/flag_file")
root = tk.Tk()
root.title("Python Countdown Timer")
root.geometry("650x130")
root.resizable(False, False)
root.attributes("-topmost", True)
title_label = tk.Label(root, text="Close this box to stop AutoScreenLock", font=("Arial", 24))
title_label.pack(pady=10)
countdown_label = tk.Label(root, text="00:00", font=("Arial", 24))
countdown_label.pack(pady=10)
start_countdown()

# Check if the file exists

root.mainloop()
Comment 5 Mik 2025-08-24 13:49:10 UTC
I dont seem to be able to edit previous comments so I had two related posts in Reddit which you might want to look at.
The original link as above, and then this one.
https://www.reddit.com/r/NobaraProject/comments/1my4wzd/maybe_old_hat_or_no_longer_needed_but_autolocker/?utm_source=share&utm_medium=web3x&utm_name=web3xcss&utm_term=1&utm_content=share_button
Comment 6 Nate Graham 2025-08-26 20:52:02 UTC
Please don't reference Reddit; we need all information to be here, summarized concisely. The more un-actionable information in the ticket, the less of a chance it'll be investigated and fixed.
Comment 7 Atom 2025-08-28 20:10:36 UTC
I have the same issue in Nobara 42, It appeared after a kernel upgrade and restart, alongside removed functionality of Autostarts. Restart, log out and shutdown buttons close most apps but doesn't actually execute its final task (actually shutting down, restarting or logging out)