After 'Switch user', entering password doesn't return to the session

[Iain Lane]

1. Lock screen (ctrl-alt-l)
2. Click 'switch user'
3. Enter password to return to session
4. The greeter disappears as if the session is being restored, then it returns

At 4, I should be logged in to my session.

I switched vt manually (ctrl-alt-f7) to get back in. In my lightdm log, these lines:

[+5871.21s] DEBUG: Activating VT 8
[+5871.21s] WARNING: Error using VT_ACTIVATE 8 on /dev/console: Inappropriate ioctl for device
[+5871.21s] WARNING: Error using VT_WAITACTIVE 8 on /dev/console: Inappropriate ioctl for device
[+5877.23s] DEBUG: Seat: Switching to existing greeter
[+5877.23s] DEBUG: Activating VT 8
[+5877.23s] WARNING: Error using VT_ACTIVATE 8 on /dev/console: Inappropriate ioctl for device
[+5877.23s] WARNING: Error using VT_WAITACTIVE 8 on /dev/console: Inappropriate ioctl for device

were when I was trying from step 1 again to see if this bug was reproducible. It would not switch back to the greeter vt (vt8). I was just left on gnome-screensaver.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: lightdm 1.9.8-0ubuntu1
ProcVersionSignature: Ubuntu 3.13.0-16.36-generic 3.13.5
Uname: Linux 3.13.0-16-generic x86_64
ApportVersion: 2.13.3-0ubuntu1
Architecture: amd64
CurrentDesktop: Unity
Date: Mon Mar 10 11:00:45 2014
InstallationDate: Installed on 2012-10-07 (518 days ago)
InstallationMedia: Ubuntu 12.10 "Quantal Quetzal" - Beta amd64 (20121007)
LightdmConfig:
 [SeatDefaults]
 user-session=ubuntu
 greeter-session=unity-greeter
SourcePackage: lightdm
UpgradeStatus: Upgraded to trusty on 2013-05-07 (307 days ago)

[Iain Lane (laney)]

This is suspicious. I'm running lxc.

laney@raleigh> ls -l /dev/console
lrwxrwxrwx 1 root root 11 Mar 10 09:29 /dev/console -> lxc/console

[Iain Lane (laney)]

Yeah. I rebooted and it works before starting the container and breaks after.

I also can't use ttys 1-4 (that's how many the container has) after starting it. "Unable to determine your TTY name." after entering my username.

[Serge Hallyn (serge-hallyn)]

Thanks for submitting this bug.

Can you tell us exactly how you created the container?

It sounds like you may have a container with devtmpfs mounted in /dev, which will cause all changes in the container's /dev to show up on the host's /dev.

[Iain Lane (laney)]

Yeah, Stéphane just pointed that out to me.

I don't know that I added it myself, but if you're sure that I couldn't have got this from Ubuntu then it must be my fault. Thanks.

[Stéphane Graber (stgraber)]

Not actually your fault, we had a 20 days window between ubuntu37 and ubuntu38 in quantal where we indeed added that broken line... Not much we can do about it unfortunately as trying to find and fix existing containers config is almost certainly going to cause more problem than it'd resolve...