Bug 500498

Summary: Screen content displayed before lock screen when waking up from sleep
Product: [Plasma] plasmashell Reporter: kbtr.buffer098
Component: Screen lockingAssignee: Plasma Bugs List <plasma-bugs-null>
Status: RESOLVED DUPLICATE    
Severity: grave CC: john.kde, kdedev, nate
Priority: NOR    
Version First Reported In: 6.3.1   
Target Milestone: 1.0   
Platform: unspecified   
OS: Linux   
Latest Commit: Version Fixed In:
Sentry Crash Report:

Description kbtr.buffer098 2025-02-21 00:37:03 UTC
SUMMARY

Waking up from sleep, the lock screen takes a second to show up and in the moment, it glitches showing the actual unlocked screen. It's enough time for whoever wakes up the computer to read a good deal of information before the lock screen appears, which turns this into a privacy problem.

This is always reproduceable and it does not matter how long you wait between sleeping and waking up, which could rule out the lock delay. And still, if the lock delay was what was happening here, the lock screen wouldn't show up asking for a password anyway.

It happens both under X11 and Wayland. Showing the desktop longer on X11 and on Wayland just for a fraction of a second, but still showing it.

STEPS TO REPRODUCE
1. Put the computer to sleep (either by clicking the sleep button, or closing the laptop lid, it doesn't matter).
2. Wait a bit, to ensure the computer fully goes to sleep. I wait for my laptop power led to start blinking, you can also go away for a few hours, it makes no difference.
3. Wake the computer up, by pressing any key or opening the laptop lid.

OBSERVED RESULT

- The laptop wakes up.
- The "contents" of the screen are visible for a moment.
- The lock screen covers everything and I'm required to type my password.

EXPECTED RESULT

- The laptop wakes up.
- Either:
    - The lock screen shows up right away, without allowing for any glitching.
    - If the lock screen takes a moment to show up, the screen should be blank.

SOFTWARE/OS VERSIONS

KDE Plasma Version: 6.3.1
KDE Frameworks Version: 6.11.0
Qt Version: 6.8.2
Comment 1 John Veness 2025-02-25 18:12:17 UTC
I've noticed this too, starting somewhere within Plasma 6.2.x. It was OK before that. Running X11.
Comment 2 TraceyC 2025-02-27 01:53:38 UTC
This looks like the same issue as in bug 485085. Please follow that report for updates. Thanks!

*** This bug has been marked as a duplicate of bug 485085 ***