Greeter uses previous session even if it is not available

[pseudonomous]

I install using preseed files, and clobber a bit of /etc to configure ubuntu to be suitable for users to login with network credentials. I use pam to make a home directory when users login with network credentials.

On first boot, logging into the VTs works fine but I cannot log into the lightdm dislpay manager. If I type my username and password right, I get a "Failed to start session" message and get bounced back to the start of the login process.

If, however, I click one of the session types, e.g. 'ubuntu' or 'fluxbox', then I can log in. (I've tried uninstalling fluxbox, this doesn't seem to help). At which point I can login, which I believe works until I reboot the machine. (I will test this shortly).

If I install the lightdm-gtk-greeter package then I do not encounter this bug. Instead, I am automatically logged into the alphabetically first session type (at least, if I've got fluxbox available vs. either ubuntu or xfce, that seems to be what I get, if only ubuntu is install I get an ubunut session by default so I assume the preference is alphabetical).

It does not seem to matter if I specify a
user-session=something
(I have also tried not setting user-session at all)

in lightdm.conf (well, I haven't tried it with the gtk-greeter, but it doesn't matter with the unity greeter).

I've tried all of the other lightdm-greeter packages, and lightdm-greeter-gtk is the only one that does not suffer from this bug.

the most relvant message in the logs I can find is:

DEBUG: Seat: Failed to find session configuration true
Seat: Can't find session 'true'

What I would expect to happen is to get some default session; getting the alphabetically first session is kind-of/sort-of reasonable. Total failure is not.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: lightdm 1.10.0-0ubuntu3
ProcVersionSignature: Ubuntu 3.13.0-24.46-generic 3.13.9
Uname: Linux 3.13.0-24-generic x86_64
NonfreeKernelModules: openafs
ApportVersion: 2.14.1-0ubuntu3
Architecture: amd64
CurrentDesktop: Unity
Date: Thu Apr 24 22:08:08 2014
LightdmConfig:
 [SeatDefaults]
 user-session=true
 greeter-hide-users=true
 greeter-allow-guest=false
 session-setup-script=/bin/sh -l /etc/profile
SourcePackage: lightdm
UpgradeStatus: No upgrade log present (probably fresh install)

[Launchpad Janitor (janitor)]

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

[ghreyes71 (ghreyes71)]

I suffer the same issue.
------------------------------------------------------
------------------------------------------------------
Distributor ID: Ubuntu
Description: Ubuntu 14.04 LTS
Release: 14.04
Package: lightdm 1.10.1-0ubuntu1
Greeter: unity-greeter 14.04.10-0ubuntu1
Uname: Linux 3.13.0-24-generic i686
Architecture: i686
CurrentDesktop: Mate
AlternativeDesktop: Unity
------------------------------------------------------
/etc/lightdm/lightdm.conf

[SeatDefaults]
user-session=true
greeter-session=unity-greeter
allow-guest = false
greeter-hide-users = true
greeter-show-manual-login = true
------------------------------------------------------
/usr/share/xsessions/lightdm-xsession.desktop

Exec=mate-session
------------------------------------------------------
/var/log/auth.log

lightdm: pam_succeed_if(lightdm:auth): requirement "user ingroup nopasswdlogin" not met by user "tester1"
lightdm: pam_unix(lightdm:auth): authentication failure; logname= uid=0 euid=0 tty=:0 ruser= rhost= user=tester1
lightdm: pam_winbind(lightdm:auth): getting password (0x00000388)
lightdm: pam_winbind(lightdm:auth): pam_get_item returned a password
lightdm: pam_winbind(lightdm:auth): user 'stoledo' granted access
<< and nothing more logged :-\ >>
------------------------------------------------------
/var/log/lightdm/lightdm.log

[+71.88s] DEBUG: Session pid=4209: Continue authentication
[+71.90s] DEBUG: Session pid=4685: Got 1 message(s) from PAM
[+71.90s] DEBUG: Session pid=4209: Prompt greeter with 1 message(s)
[+76.41s] DEBUG: Session pid=4209: Continue authentication
[+76.73s] DEBUG: Session pid=4685: Authentication complete with return value 0: Success
[+76.73s] DEBUG: Session pid=4209: Authenticate result for user tester1: Success
[+76.73s] DEBUG: Session pid=4209: User tester1 authorized
[+76.73s] DEBUG: Session pid=4209: Greeter requests default session
[+76.73s] DEBUG: Seat: Failed to find session configuration true
[+76.73s] DEBUG: Seat: Can't find session 'true '
[+76.73s] DEBUG: Session pid=4209: Greeter start authentication
[+76.74s] DEBUG: Session pid=4735: Started with service 'lightdm', username '(null)'
[+76.74s] DEBUG: Session pid=4685: Exited with return value 0

[ghreyes71 (ghreyes71)]

This is the /var/log/lightdm/lightdm.log with lightdm-gtk-greeter

[+1542.13s] DEBUG: Session pid=10322: Greeter start authentication for tester1
[+1542.13s] DEBUG: Session pid=10417: Sending SIGTERM
[+1542.13s] DEBUG: Session pid=10481: Started with service 'lightdm', username 'tester1'
[+1542.13s] DEBUG: Session pid=10417: Terminated with signal 15
[+1542.13s] DEBUG: Session: Failed during authentication
[+1542.13s] DEBUG: Seat: Session stopped
[+1542.14s] DEBUG: Session pid=10481: Got 1 message(s) from PAM
[+1542.14s] DEBUG: Session pid=10322: Prompt greeter with 1 message(s)
[+1546.55s] DEBUG: Session pid=10322: Continue authentication
[+1546.84s] DEBUG: Session pid=10481: Authentication complete with return value 0: Success
[+1546.84s] DEBUG: Session pid=10322: Authenticate result for user tester1: Success
[+1546.84s] DEBUG: Session pid=10322: User tester1 authorized
[+1546.84s] DEBUG: Session pid=10322: Greeter sets language es_AR
[+1546.89s] DEBUG: Session pid=10322: Greeter requests session mate
[+1546.89s] DEBUG: Seat: Stopping greeter; display server will be re-used for user session
[+1546.89s] DEBUG: Session pid=10322: Sending SIGTERM
[+1546.93s] DEBUG: Session pid=10322: Greeter closed communication channel
[+1546.93s] DEBUG: Session pid=10322: Exited with return value 0
[+1546.93s] DEBUG: Seat: Session stopped
[+1546.93s] DEBUG: Seat: Greeter stopped, running session
[+1546.93s] DEBUG: Registering session with bus path /org/freedesktop/DisplayManager/Session2
[+1546.94s] DEBUG: Session pid=10481: Running command /usr/sbin/lightdm-session mate-session
[+1546.94s] DEBUG: Creating shared data directory /var/lib/lightdm-data/tester1
[+1546.94s] DEBUG: Session pid=10481: Logging to .xsession-errors
[+1546.97s] DEBUG: Activating VT 7
[+1546.97s] DEBUG: Activating login1 session /org/freedesktop/login1/session/c21
[+1548.62s] DEBUG: User /org/freedesktop/Accounts/User1006 changed
[+1548.65s] DEBUG: User /org/freedesktop/Accounts/User5514 changed
[+1548.67s] DEBUG: User /org/freedesktop/Accounts/User1001 changed

lightdm-gtk-greeter WORKS !!
unity-greeter FAIL !!

I'm using Ubuntu 14.04 + LightDM + Mate DE + Samba + Winbind (against Active Directory)

[ghreyes71 (ghreyes71)]

Today, lightdm-gtk-greeter fail too.

I was setting the gtk greeter and decided to remove the session indicator. And after that, the problems started again. I removed the ubuntu-desktop package, leaving only Mate Desktop but the "error on logon" message continued. I decided to return the session indicator and the problem disappeared.

The indicator provides no role for me and my users because only MATE is installed now, and I set this in /etc/skel for default. But serves to mark a desktop to start, option that has no effect on the working environment but avoid the session error.

Sorry for my english

[ghreyes71 (ghreyes71)]

Yesterday, lightdm-gtk-greeter fail with message "error on logon" sometines... and sometimes LightDM not let me type in text fields (user and password) until I selected the session in the indicator session.

Today, worked well until lunchtime.

Upon returning from my lunch and try again my Ubuntu gave me *wrong password* error (using LightDM + gtk-greeter).
When trying from a VT all works fine. We tried with several users and the result was always the same.
I decided to restart LightDM and the problem was corrected.

[Launchpad Janitor (janitor)]

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

[Arvind Kumar (phenom-arvind)]

I lost my faith in ubuntu that they can deliver a good product.
lightdm does not restart ,xorg server does not start.

I had to format my machine.

Please resolve all these issue on priority people affected very badly rather than releasing ubuntu 14.10.

[[e-mail] (htmldeveloper)]

Arvind, did you try this:

sudo apt-get install ubuntu-desktop

(as described here: http://askubuntu.com/questions/450567/failed-to-start-session-after-interrupted-upgrade-to-14-04)

I got the same error as you and this worked for me.

[pseudonomous (fdruec1)]

Arvind, this is *not* the same bug. This bug is a problem with every
lightdm greeter package except the gtk greeter failing to start a desktop
session unless the user manually selects a desktop session.

Perhaps you encountered this bug:

https://bugs.launchpad.net/lightdm/+bug/971891

instead?

Hopefully:

Perhaps htmldevelopers suggestion will help you.

Another thing you can try doing is replacing lightdm with another display
manager like gdm or slim.

If you boot in recovery-mode, select the fsck option, start networking, and
drop to a console you can do:

apt-get update
apt-get install gdm

and select gdm as your default display manager.

It may not look pretty (though you can change the theme to improve that)
but it may work better than lightdm.'

But you should probably look for help in the wiki or forums instead of the
bug tracker.

On Sat, Sep 13, 2014 at 2:58 PM, Arvind Kumar <email address hidden>
wrote:

> I lost my faith in ubuntu that they can deliver a good product.
> lightdm does not restart ,xorg server does not start.
>
> I had to format my machine.
>
> Please resolve all these issue on priority people affected very badly
> rather than releasing ubuntu 14.10.
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1312526
>
> Title:
> lightdm fails to start session unless user selects session
>
> Status in “lightdm” package in Ubuntu:
> Confirmed
> Status in “lightdm-gtk-greeter” package in Ubuntu:
> Confirmed
> Status in “unity-greeter” package in Ubuntu:
> Confirmed
>
> Bug description:
> I install using preseed files, and clobber a bit of /etc to configure
> ubuntu to be suitable for users to login with network credentials. I
> use pam to make a home directory when users login with network
> credentials.
>
> On first boot, logging into the VTs works fine but I cannot log into
> the lightdm dislpay manager. If I type my username and password
> right, I get a "Failed to start session" message and get bounced back
> to the start of the login process.
>
> If, however, I click one of the session types, e.g. 'ubuntu' or
> 'fluxbox', then I can log in. (I've tried uninstalling fluxbox, this
> doesn't seem to help). At which point I can login, which I believe
> works until I reboot the machine. (I will test this shortly).
>
> If I install the lightdm-gtk-greeter package then I do not encounter
> this bug. Instead, I am automatically logged into the alphabetically
> first session type (at least, if I've got fluxbox available vs. either
> ubuntu or xfce, that seems to be what I get, if only ubuntu is install
> I get an ubunut session by default so I assume the preference is
> alphabetical).
>
> It does not seem to matter if I specify a
> user-session=something
> (I have also tried not setting user-session at all)
>
> in lightdm.conf (well, I haven't tried it with the gtk-greeter, but it
> doesn't matter with the unity greeter).
>
> I've tried all of the other lightdm-greeter packages, and lightdm-
> greeter-gtk is the only one that does not suffer from this bug.
>
> the most relvant message in ...

[Robert Ancell (robert-ancell)]

Removing lightdm task as it is the responsibility of the greeters to choose a valid session.

[Robert Ancell (robert-ancell)]

This is particularly bad in Unity Greeter when only one session type is available - it doesn't even show the control to pick a session meaning you can never log in without modifying the stored value from a command line.

[Olaf Waszkewitz (olaf-c)]

I had the same problem which can be easily reproduced this way:
I am logged in on PC A with user “olaf”. Using ssh I log in at PC B with user “chief” and start x:
olaf@A: ssh chief@B
olaf@A: sudo startx
X-Session really starts up on B which I can see.
Then I press ctrl+c
… connection to x server lost

Now I move over to PC B and want to login with user “chief”.
I can't get passed the login screen.
In /var/log/lightdm/lightdm.log I found the following:

[+10.72s] DEBUG: Session pid=1556: Greeter connected version=1.16.7 resettable=false
[+10.91s] DEBUG: Session pid=1556: Greeter start authentication for chief
[+10.91s] DEBUG: Session pid=1609: Started with service 'lightdm', username 'chief'
[+10.92s] DEBUG: Session pid=1609: Got 1 message(s) from PAM
[+10.92s] DEBUG: Session pid=1556: Prompt greeter with 1 message(s)
[+23.13s] DEBUG: Session pid=1556: Greeter start authentication for olaf
[+23.13s] DEBUG: Session pid=1609: Sending SIGTERM
[+23.13s] DEBUG: Session pid=1777: Started with service 'lightdm', username 'olaf'
[+23.13s] DEBUG: Session pid=1609: Terminated with signal 15
[+23.13s] DEBUG: Session: Failed during authentication
[+23.13s] DEBUG: Seat seat0: Session stopped

It seems that lightdm wants to login with user “olaf” and the password I just entered (Greeter start authentication for olaf).
Of course this will fail on PC B.

Deleting the file Xauthority in the home of user chief on PC B will allow me to login again as chief:
chief@B: mv ~/.Xauthority

[Olaf Waszkewitz (olaf-c)]

Sorry, the correct command is
sudo rm /home/chief/.Xauthority

[Sean Davis (bluesabre)]

Is this still a problem with either greeter?

[Launchpad Janitor (janitor)]

[Expired for lightdm-gtk-greeter (Ubuntu) because there has been no activity for 60 days.]