Ubuntu
gnome-screensaver package

screen lock by timeout does not affect vm

Bug #1124282 reported by Fabian Kaczmarczyck on 2013-02-13

This bug report is a duplicate of: Bug #49579: screen doesn't lock when some menu is open. Edit Remove

262

This bug affects 2 people

Affects		Status	Importance	Assigned to	Milestone
	gnome-screensaver (Ubuntu)	Opinion	Undecided	Unassigned

Bug Description

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'

Tags:

Revision history for this message

Fabian Kaczmarczyck (fabian-kaczmarczyck) wrote on 2013-02-13:

#1

Dependencies.txt Edit (4.5 KiB, text/plain; charset="utf-8")
GsettingsGnomeLockdown.txt Edit (430 bytes, text/plain; charset="utf-8")
GsettingsGnomePowerManager.txt Edit (1.7 KiB, text/plain; charset="utf-8")
GsettingsGnomeScreensaver.txt Edit (602 bytes, text/plain; charset="utf-8")
XorgConf.txt Edit (1.7 KiB, text/plain; charset="utf-8")
XorgLog.txt Edit (18.9 KiB, text/plain; charset="utf-8")
XorgLogOld.txt Edit (19.4 KiB, text/plain; charset="utf-8")

Revision history for this message

Seth Arnold (seth-arnold) wrote on 2013-02-16:

#2

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.

information type:	Private Security → Public Security
Changed in gnome-screensaver (Ubuntu):
status:	New → Opinion

Revision history for this message

Fabian Kaczmarczyck (fabian-kaczmarczyck) wrote on 2013-02-17:

#3

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.

Revision history for this message

Marc Deslauriers (mdeslaur) wrote on 2013-02-17:

#4

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

Revision history for this message

Patrik Nilsson (nipatriknilsson) wrote on 2017-05-28:

#5

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.

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