screen lock by timeout does not affect vm

[Fabian Kaczmarczyck]

I have a virtualbox running a Windows 7 64 bit on my Ubuntu 12.04 64 bit. If the Windows window is on focus and i am inactive, then my screen is locked after a certain amount of time and should normally ask for my password. But it only does so if a change the focus to a window other than my virtual machine.

Worse than that, if I hurry after my screen should be locked, I perform some actions on my Ubuntu host before the password prompt locks the screen. So the presence of my virtualbox allows people to open a terminal on the host and type any command in the worst case. This is a security issue.

Ubuntu: 12.04 64 bit
Window Manager: gnome-shell
VM: Oracle VM VirtualBox Manager 4.1.12_Ubuntu
Screen saver: gnome-screensaver 3.4.1

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: gnome-screensaver 3.4.1-0ubuntu1
ProcVersionSignature: Ubuntu 3.2.0-37.58-generic 3.2.35
Uname: Linux 3.2.0-37-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.0.1-0ubuntu17.1
Architecture: amd64
Date: Wed Feb 13 17:19:45 2013
GnomeSessionIdleInhibited: No
GnomeSessionInhibitors: None
GsettingsGnomeSession:
 org.gnome.desktop.session idle-delay uint32 600
 org.gnome.desktop.session session-name 'ubuntu'
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Release amd64 (20120423)
MarkForUpload: True
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 LANG=de_DE.UTF-8
 SHELL=/bin/bash
SourcePackage: gnome-screensaver
UpgradeStatus: No upgrade log present (probably fresh install)
WindowManager: No value set for `/desktop/gnome/session/required_components/windowmanager'

[Seth Arnold (seth-arnold)]

Thanks for the report.

Any X11 client is allowed to grab the keyboard and mouse, and thus prevent the session from locking. Time-based locking is not guaranteed to function. If you wish your X11 session locked when you're away, please lock it manually.

Thanks.

[Fabian Kaczmarczyck (fabian-kaczmarczyck)]

There could be a problem of bad information. Because the screen is locked, you can see it go black and you need to enter our password. But befor you do, you can either use the guest system (tested with a Windows guest) or perform arbitrary actions for a few seconds. I see that this is not really a big issue, but I think it is an inconsistency.

[Marc Deslauriers (mdeslaur)]

The virtual machine window is grabbing the keyboard and mouse, which prevents the screensaver process from starting properly. While the screensaver is stuck waiting to grab the keyboard or mouse, DPMI blanks the screen. When you get back, by moving the mouse you clear the keyboard/mouse grab and then the screensaver process grabs them and starts up. This is a longstanding issue, and there's nothing that can be done to fix this with the current design of xorg. This is a dupe of bug 49579

[Patrik Nilsson (nipatriknilsson)]

Fails with Virtualbox in focus:

user@ubuntu:~$ sleep 20s; gnome-screensaver-command --lock

Works with Virtualbox in focus:

user@ubuntu:~$ sleep 20s; wmctrl -k on; gnome-screensaver-command --lock

Works with Virtualbox in focus:

user@ubuntu:~$ sleep 20s; wmctrl -k on; gnome-screensaver-command --lock; wmctrl -k off

Works with Virtualbox in focus:

user@ubuntu:~$ sleep 20s; wmctrl -k on; gnome-screensaver-command --lock; sleep 1s; wmctrl -k off

Works with Virtualbox in focus:

user@ubuntu:~$ sleep 20s; wmctrl -k on; gnome-screensaver-command --lock; wmctrl -k off

I can't understand why it couldn't be fixed.