I've found a way to trigger this without needing to suspend (which hopefully will make it easier to debug :-)...
1) Open a terminal. 2) Run: "sleep 5 && gnome-terminal --maximize" 3) Quickly (before 5 seconds has elapsed), press "CTRL+l" to lock the screen. 4) Don't touch keyboard or mouse for about 10 seconds to give the lock screen time to dim the screen to black. 5) *Before* the cursor disappears (normally happens about 2 seconds after the screen is fully black), tpe random characters or hold down a key continually until the lock screen is displayed again. 6) Either delete the characters in the password box and reenter you actual password, or press return and enter you actual password. 7) Observe that the maximised gnome-terminal that is now revealed shows atleast a subset of the keys you typed when the screen was locked. -- You received this bug notification because you are a member of DX Packages, which is subscribed to unity in Ubuntu. Matching subscriptions: dx-packages https://bugs.launchpad.net/bugs/1345505 Title: lock screen leaks keystrokes to window "behind" greeter Status in “unity” package in Ubuntu: New Bug description: When my machine comes out of suspend, I am shown the lightdm greeter. However, occasionally I am unable to enter my password since the password box is not given focus. Clicking with the mouse in the password box also doesn't help. I've found that clicking the settings cog (top right) twice allows me to regain control of the focus and enter my password. Aside from the inability to enter my password in the password box, it seems that simply typing my password (or in fact any text) results in those keystrokes being passed to the full-screen window *behind* the greeter. This should not be possible and is a security issue: imagine if my full-screen console was connected to a remote shared session, or was running an irc client, etc.). ProblemType: Bug DistroRelease: Ubuntu 14.10 Package: lightdm 1.11.4-0ubuntu1 ProcVersionSignature: Ubuntu 3.16.0-4.9-generic 3.16.0-rc5 Uname: Linux 3.16.0-4-generic x86_64 ApportVersion: 2.14.4-0ubuntu2 Architecture: amd64 CurrentDesktop: Unity Date: Sun Jul 20 09:08:47 2014 InstallationDate: Installed on 2014-04-11 (99 days ago) InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Daily amd64 (20140409) SourcePackage: lightdm UpgradeStatus: Upgraded to utopic on 2014-05-08 (72 days ago) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/unity/+bug/1345505/+subscriptions -- Mailing list: https://launchpad.net/~dx-packages Post to : dx-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~dx-packages More help : https://help.launchpad.net/ListHelp