Unable to unlock session after locking with VirtualBox VM running in fullscreen

[Donarsson]

When I lock the screen while a VirtualBox VM is running in fullscreen, the lockscreen doesn't react to any input, keyboard or mouse.

As a workaround, it's possible to switch to a workspace without a fullscreen VM or to leave fullscreen before locking the screen.

This bug affects other users aswell, see here: http://askubuntu.com/questions/433372/unable-to-unlock-after-locking-when-virtualbox-is-in-full-screen-mode

I'll do more tests to narrow the issue down and update the bug.
If you need me to perform any specific tests, I'll gladly do so.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: unity 7.2.0+14.04.20140416-0ubuntu1
ProcVersionSignature: Ubuntu 3.13.0-24.46-generic 3.13.9
Uname: Linux 3.13.0-24-generic x86_64
ApportVersion: 2.14.1-0ubuntu3
Architecture: amd64
CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CurrentDesktop: Unity
Date: Thu Apr 24 18:54:52 2014
InstallationDate: Installed on 2014-04-10 (14 days ago)
InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Daily amd64 (20140410)
SourcePackage: unity
UpgradeStatus: No upgrade log present (probably fresh install)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Umut Erol Kaçar (umutkacar)]

I too experienced the same issue. As a workaround:

1) Alt+F2 to console window and login,
2) Type unity --replace and hit Enter.

...and now the keyboard is working on the lock-screen again.

[cduff (mailduff)]

Workaround that works for me: Hit Right Ctrl (virtualbox host key) then click the clock or shutdown menu at the top until it responds. Keyboard control will be returned to the lock screen.

A note: any keyboard input from the lock screen will be passed thru to the full screen VM (i.e. your password).

[Matthew Monaco (mwtt)]

My workaround is to switch users and re-entre my username/password from there. When lightdm unlocks, everything is fine, its compiz that has the problem.