gnome-screensaver incorrectly monitors activity in virtual machines

[Andy Ruddock]

Binary package hint: gnome-screensaver

I have virtual machines running both Ubuntu and Windows, whilst working in a virtual screen the screensaver doesn't kick in (as expected).
However, upon moving the mouse out of the virtual screen if the period I've been working has exceeded the timeout of the screensaver then it kicks in, as I'm moving the mouse, and I then have to re-enter my password to continue working.
I'm using the latest karmic with virt-manager to control & launch virtual machines.

$ lsb_release -rd
Description: Ubuntu 9.10
Release: 9.10

$ apt-cache policy gnome-screensaver
gnome-screensaver:
  Installed: 2.28.0-0ubuntu3
  Candidate: 2.28.0-0ubuntu3
  Version table:
 *** 2.28.0-0ubuntu3 0
        500 http://gb.archive.ubuntu.com karmic/main Packages
        100 /var/lib/dpkg/status

[bastafidli (ubuntu-bastafidli)]

I seem to have the same or similar problem. I am running Ubuntu 10.04 as host and I am running Windows XP as Guest in VMware player 3.1. I am spending most of my time in the Windows XP guest. My blank screen saver is set to start after 5 minutes and lock the screen. I can go away sometimes for more than 5 minutes and the screen saver doesn't start. When I come back, I can start working and sometimes in few seconds, sometimes in few minutes, the screensaver suddenly starts and lock my screen even though I have been moving my mouse or typing (either in the guest or in the host). This is highly insecure and annoying since the machine doesn't lock the screen as expected and whoever can come and work on the machine after the screensaver was supposed to start and use the machine for minutes before the screensaver suddenly randomly kicks in.

[Pedro Villavicencio (pedro)]

Thank you for taking the time to report this bug and helping to make Ubuntu better.You reported this bug a while ago and there hasn't been any activity in it recently. We were wondering is this still an issue for you? Do you get the same with latest Lucid packages or in Maverick? Thanks in advance.

[bastafidli (ubuntu-bastafidli)]

Yes, this problem is still present with latest updates in 10.04.

[Marc Deslauriers (mdeslaur)]

This is what's happening: When you work in the VMWare, the screensaver timeout expires and gnome-screensaver tries to grab the mouse. Since VMWare won't let it, it keeps trying. Once you leave the VMWare window, it becomes successful in grabbing the mouse and starts the screensaver.

This is a well-known issue that is documented here:

https://wiki.ubuntu.com/DebuggingScreenLocking#gnome-screensaver%20cannot%20grab%20keyboard%20or%20mouse

Since this is basically the same issue as bug 49579, I am marking this bug as a duplicate, even though bug 49579 may not specifically mention VMWare.

Thanks for reporting this issue.

[bastafidli (ubuntu-bastafidli)]

I agree it seems like the same bug, but the side effect of this bug are worse. With the other bug the screensaver kicks in as soon as you click somwhere. With this bug, the machine allows you to use it for a while either in VM or in Ubuntu. I can click around, I can type, etc and only after a while the screen locks. This make this vulnerability worse IMHO.

[Jordi Guillaumes (jguillaumes)]

Still present in 10.10.

[John Cottier (j-cottier)]

Yes this bug affects me too. While working in the guest, the host screen saver is inhibited (by vmware) which is correct, but it seems that the screensaver is unaware of any activity in the guest. So as soon as the mouse moves outside of the guest host desktop, the screensaver immediately starts. Insecure, and a right pain. But the bug 49579 seems a different issue to me. I have used vmware since Feisty and never had this issue before. But whether its a vmware bug or an Ubtuntu one I have no idea.