Bug 350268

Summary: Security flaw. Screen locker upon resume shows real desktop image briefly.
Product: [Unmaintained] ksmserver Reporter: empire
Component: lockscreenAssignee: David Edmundson <kde>
Status: RESOLVED DUPLICATE    
Severity: grave CC: bshah, empire, plasma-bugs
Priority: NOR    
Version First Reported In: unspecified   
Target Milestone: ---   
Platform: Arch Linux   
OS: Linux   
Latest Commit: Version Fixed In:
Sentry Crash Report:

Description empire 2015-07-15 23:44:48 UTC 
When I resume the laptop from suspend to ram (by opening the lid), the monitor shows for half a second the whole desktop as it was before I closed the lid and then the locker comes up.

This is a very serious security risk because someone can see all your opened programs before you closed and suspended the computer. Someone can easily capture with a camera the half-a-second image and see sensitive information.

Reproducible: Always

Steps to Reproduce:
1. suspend laptop (e.g. close lid)
2. resume (e.g. open lid)
3.

Actual Results:  
The monitor displays for half a second the desktop with all open programs and then displays the fullscreen locker.

Expected Results:  
Locker should be the only thing that the monitor display from the very first frame.

Laptop thinkpad t410
graphics intel HD
Comment 1 David Edmundson 2015-07-17 23:53:39 UTC 
Do you use systemd?
Comment 2 empire 2015-07-30 17:49:04 UTC 
yes. systemd 222.
Comment 3 David Edmundson 2015-07-30 17:52:59 UTC 
Can you paste the output of "systemd-inhibit" please
Comment 4 empire 2015-07-30 17:58:02 UTC 
yes here it is:

[nektarios@neklaptop ~]$ systemd-inhibit 
     Who: Screen Locker (UID 1000/nektarios, PID 11106/ksmserver)
    What: sleep
     Why: Ensuring that the screen gets locked before going to sleep
    Mode: delay

     Who: NetworkManager (UID 0/root, PID 250/NetworkManager)
    What: sleep
     Why: NetworkManager needs to turn off networks
    Mode: delay

     Who: PowerDevil (UID 1000/nektarios, PID 11093/kded5)
    What: handle-power-key:handle-suspend-key:handle-hibernate-key:handle-lid-switch
     Why: KDE handles power events
    Mode: block

3 inhibitors listed.
Comment 5 David Edmundson 2015-07-30 18:01:36 UTC 
Thanks
Comment 6 Martin Flöser 2015-08-25 07:53:58 UTC 

*** This bug has been marked as a duplicate of bug 348850 ***