GDM 3 disable-user-list=true does not work with gnome-shell greeter

[Evan Brown]

[Impact]
It's not possible to hide the list of users on the gdm lock screen. This is considered a security vulnerability in some environments.

[Test Case]

* Install gnome-shell and set gdm as your default display manager. Reboot (or kill lightdm and start gdm)
* If you have ubuntu-gnome-default-settings installed, just add
disable-user-list=true
as a new line at the bottom of /usr/share/glib-2.0/schemas/20_ubuntu-gnome-default-settings.gschema.override.

Otherwise, create a new file named /usr/share/glib-2.0/schemas/20_disable-user-list.gschema.override and add these two lines:
[org.gnome.login-screen]
disable-user-list=true

* sudo service gdm restart
* The userlist should not show up on the login screen.

[Regression Potential]
Minimal. This fix is included in the gnome-shell 3.6.2 update (bug 1078155)

Original bug report
===================
when you edit /etc/gdm/greeter.gsettings > org.gnome.login-screen > disable-user-list=true it has no effect.

when you run "sudo gsettings set org.gnome.login-screen disable-user-list true" it has no effect.

The only way I have been able to get a user to not show up in the user list has been to set the uid < 1000. This is a horrible hack and not viable.

lsb_release -rd
Description: Ubuntu 12.10
Release: 12.10

gdm:
  Installed: 3.6.1-0ubuntu1
  Candidate: 3.6.1-0ubuntu1
  Version table:
 *** 3.6.1-0ubuntu1 0
        500 http://us.archive.ubuntu.com/ubuntu/ quantal/universe amd64 Packages
        100 /var/lib/dpkg/status

[Tim Lunn (darkxst)]

greeter.gsettings is a file that was added by the debian package, however the relevant patch to support this file is no longer available. Really we should remove this file from /etc since being there implies that it should work. Either we could move it the schema folder or the docs folder I suppose.

Additionally I believe that the gnome-shell greeter does not support most of the overrides in greeter.gsettings, you need to use gdm fallback if you want those options.

[Tim Lunn (darkxst)]

looking at upstream bug, this might be implemented for gnome-shell greeter in 3.6.2

[Collin O'Reilly (collin-o)]

Same with Ubuntu Gnome Remix 12.10 - editing has no affect, editing greeter settings file either manually or with gsettings.

Not advised to edit user uid or /etc/login.defs file as workaround, to hide uid's, unless you never intend to lock your screen. If you use screen lock, after screen locks you can't log back in. The gnome shell lock is a wallpaper clock that you need to slide up out of the way to unlock. After you slide it up, although you can see your loging id and picture, you can't type in your password that field isn't activate. You also cannot execut ctl+alt+f1 to drop to cli, nor is there an option on lock screen for shutdown or restart. The user gets stuck there and is forced to do a hard shutdown. At least, I wasn't able to find any gradeful way out of that mess...!!! lol

[Launchpad Janitor (janitor)]

This bug was fixed in the package gnome-shell - 3.6.2-0ubuntu1

---------------
gnome-shell (3.6.2-0ubuntu1) raring; urgency=low

  * New upstream release. (LP: #1078155)
    - Fixes disable-user-list option (LP: #1072838)
  * debian/control.in
    - Bump minimum mutter
    - Build-depend on gtk-doc-tools to generate updated man page
  * debian/patches/telepathyClient-Fix-auto-scroll-to-bottom.patch
    - Dropped, applied in new version
  * debian/patches/ubuntu_screensaver_fallback.patch:
    - Dropped, applied in new version
  * debian/patches/ubuntu_lock_on_suspend.patch
    - Refreshed
 -- Jeremy Bicha <email address hidden> Mon, 12 Nov 2012 23:11:33 -0500

[Adam Conrad (adconrad)]

Hello Evan, or anyone else affected,

Accepted gnome-shell into quantal-proposed. The package will build now and be available at http://launchpad.net/ubuntu/+source/gnome-shell/3.6.2-0ubuntu0.1 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please change the bug tag from verification-needed to verification-done. If it does not, change the tag to verification-failed. In either case, details of your testing will help us make a better decision.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance!

[Adam Conrad (adconrad)]

Hello Evan, or anyone else affected,

Accepted gnome-shell into quantal-proposed. The package will build now and be available at http://launchpad.net/ubuntu/+source/gnome-shell/3.6.2-0ubuntu0.2 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please change the bug tag from verification-needed to verification-done. If it does not, change the tag to verification-failed. In either case, details of your testing will help us make a better decision.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance!

[Evan Brown (noggin)]

This works as expected now. When GDM starts up, there is no user list. It just displays a simple text box that is requesting a username.

[Scott Kitterman (kitterman)]

The verification of this Stable Release Update has completed successfully and the package has now been released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regresssions.

[Launchpad Janitor (janitor)]

This bug was fixed in the package gnome-shell - 3.6.2-0ubuntu0.2

---------------
gnome-shell (3.6.2-0ubuntu0.2) quantal-proposed; urgency=low

  * debian/control.in:
    - Really bump mutter and build-depend on gtk-doc-tools

gnome-shell (3.6.2-0ubuntu0.1) quantal-proposed; urgency=low

  * New upstream release. (LP: #1078155)
    - Fixes disable-user-list option (LP: #1072838)
    - Many other bugfixes
  * debian/control.in
    - Bump minimum mutter
    - Build-depend on gtk-doc-tools to generate updated man page
  * debian/patches/ubuntu_screensaver_fallback.patch:
    - Dropped, applied in new version
  * debian/patches/ubuntu_lock_on_suspend.patch
    - Refreshed
  * debian/patches/ubuntu-lightdm-user-switching.patch:
    - Restored. Accidentally dropped earlier but it just needed to
      be refreshed (LP: #1064269)
  * debian/patches/git-set-ally-wm-theme.patch:
    - Git patch to set/reset HighContrast window theme too
 -- Jeremy Bicha <email address hidden> Mon, 26 Nov 2012 23:39:00 -0500