automatic login configured in ubiquity cannot be disabled by gnome-control-center

[Gordon Ball]

Release: vivid (fresh install with ubuntu-gnome-desktop)
Version:
    ubiquity 2.21.4
    gnome-control-center 1:3.14.2-2ubuntu1
    gdm 3.14.1-0ubuntu1

What I expected:

+ Fresh install with ubiquity, create a user with auto-login enabled
+ User logs in automatically on subsequent boots
+ Disable auto-login via System -> Users -> Unlock -> Automatic login (OFF)
+ Restart and see gdm login dialog

What happened:

+ After disabling auto-login, the user is nonetheless automatically logged if gdm is left alone for 10 seconds

If auto-login is selected in ubiquity, it appears to write the following into /etc/gdm/custom.conf (relevant code at d-i/source/user-setup/user-setup-apply:268)

    AutomaticLoginEnable=true
    AutomaticLogin=$USER
    TimedLoginEnable=true
    TimedLogin=$USER
    TimedLoginDelay=10

While toggling auto-login in gnome-control-center only appears to toggle the value after AutomaticLoginEnable (and hence, timed login remains true, and the assumption that a password should now be required is violated).

[Marc Deslauriers (mdeslaur)]

Thanks for taking the time to report this bug and helping to make Ubuntu better. We appreciate the difficulties you are facing, but this appears to be a "regular" (non-security) bug. I have unmarked it as a security issue since this bug does not show evidence of allowing attackers to cross privilege boundaries nor directly cause loss of data/privacy. Please feel free to report any other bugs you may find.

[Mathieu Trudel-Lapierre (cyphermox)]

So, seems to me like this doesn't require changes in ubiquity, closing the task as Invalid.

[Tim Lunn (darkxst)]

Mathieu, ubiquity will require a rebuild to pick up the changes (once user-setup update is released) since it directly embeds the scripts at build time. So reopening ubiquity task.

[Launchpad Janitor (janitor)]

This bug was fixed in the package user-setup - 1.48ubuntu4

---------------
user-setup (1.48ubuntu4) vivid; urgency=medium

  [ Jörn Schönyan ]
  * Handle SDDM autologin with other DMs than Plasma (LP: #1423103)

  [ Tim Lunn ]
  * Don't set TimedLogin, this gets set when Auto login is selected
    in ubiquity but there is no UI to unset it (LP: #1412791)
 -- Tim Lunn <email address hidden> Wed, 15 Apr 2015 14:39:37 -0500

[Brian Murray (brian-murray)]

ubiquity (2.21.22) vivid; urgency=medium

  * Automatic update of included source packages: partman-efi 62ubuntu2,
    user-setup 1.48ubuntu5.
  * debian/ubiquity.templates: add a string for "Continue in UEFI mode".
  * ubiquity/plugins/ubi-partman.py: Fix up the buttons for the non_efi_system
    question to use the new string for UEFI mode.
  * ubiquity/plugins/ubi-partman.py: try to reverse the meaning of the debconf
    partman-efi/non_efi_system question so that "Continue in UEFI mode" will
    actually really mean continuing with setting up an EFI System Partition
    and "Go Back" will properly return to the partitioning scheme selection
    page and allow to try again without an ESP. (LP: #1444104)