Ubuntu desktop computer doesn't seem to lock correctly

[Borys Sidoruk]

Ubuntu desktop computer doesn't seem to lock correctly if I click "Lock Screen" it does lock if I use shortcut. If I use the "lock screen" button then anyone can unlock it by merely pressing "ctrl+alt+f7".
The problem is not that I cannot lock my screen, the problem is I was under the impression that my computer was being locked when it was not.
now that I know that the "Lock Screen" button doesn't work correctly I know of other ways to lock my computer still the lock screen button should work and it looks like it locked my screen,but if I press "ctrl+alt+f7" then it magically unlocks

So it is a security incident.

Thanks in Advance.

[Ubuntu Foundations Team Bug Bot (crichton)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. It seems that your bug report is not filed about a specific source package though, rather it is just filed against Ubuntu in general. It is important that bug reports be filed about source packages so that people interested in the package can find the bugs about it. You can find some hints about determining what package your bug might be about at https://wiki.ubuntu.com/Bugs/FindRightPackage. You might also ask for help in the #ubuntu-bugs irc channel on Freenode.

To change the source package that this bug is filed about visit https://bugs.launchpad.net/ubuntu/+bug/1864982/+editstatus and add the package name in the text box next to the word Package.

[This is an automated message. I apologize if it reached you inappropriately; please just reply to this message indicating so.]

[Borys Sidoruk (boreek)]

Distribution: Ubuntu 18.04.3 LTS
Architecture: amd64
Running kernel: 4.15.0-88-generic
Kernel version: 4.15.0.88.88

[Borys Sidoruk (boreek)]

This problem is when we using LightDM.

[Borys Sidoruk (boreek)]

Hi Team,
Any updates here?

[Marc Deslauriers (mdeslaur)]

What desktop environment are you using?

[Borys Sidoruk (boreek)]

We currently using few machines and issue exist on this ubuntu environment:
Distribution: Ubuntu 18.04.3 LTS
Architecture: amd64
Running kernel: 4.15.0-88-generic
Kernel version: 4.15.0.88.88

Regarding to model machines:
Dell Precision 5530
Dell Precision 5520
Dell Precision 5510
Precision Tower 3630,
Precision Tower 3620,
Dell Latitude 5400

[Gunnar Hjalmarsson (gunnarhj)]

That's distro... I think Marc asked about if you use Ubuntu with GNOME, Xubuntu, Lubuntu, or Budgie etc.

[Borys Sidoruk (boreek)]

My bad, its GNOME.

[Gunnar Hjalmarsson (gunnarhj)]

So did you replace GDM with LightDM on your Ubuntu installs? If you didn't, this may actually be a gnome-shell and/or gdm3 issue. Please clarify.

[Borys Sidoruk (boreek)]

Problem like I described is on LightDM. When I changed to gdm3, problem is gone.

[Gunnar Hjalmarsson (gunnarhj)]

Ok, thanks. Since LightDM is not the default DM on Ubuntu 18.04, I set the importance of this bug to "Low".

[Borys Sidoruk (boreek)]

Hello,
Any news in this case?

Best Regards,
Borys Sidoruk