I've just experienced the same story as Mr. Bruno Nova (brunonova). I spent a whole day to shoot the trouble and identified that it's about .Xauthority.
I tracked the /var/log/lightdm/lightdm.log and looked into my .Xauthority. I found it contained two entries: snow/unix:1 MIT-MAGIC-COOKIE-1 f8aa6a272ab2e68533175967a9e5d09d snow.mydomain.com.tw/unix:0 MIT-MAGIC-COOKIE-1 1e9a7aeba63b74bef069a3629fe3e80a Removing the 2nd entry, which should be 'snow' instead of 'snow.mydomain.com.tw', made my system recover and logs me in again. (Usually I am the only user of this machine. The :1 entry is created when I successfully login with a new test account, and switch to login my normal account.) I don't know when it was touched and by whom. I have tried to reconfigure postfix the other day. I have changed my /etc/hostname from snow to snow.mydomain.com.tw, but I changed it back later... I think short hostname is better for my administration. Such condition rarely happens. It looks .Xauthority is seldom updated except necessity. However it(the greeter?) could be more robust for such cases. -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to lightdm in Ubuntu. https://bugs.launchpad.net/bugs/1234400 Title: Cannot log in users if their Xauthority file is corrupt. Status in Light Display Manager: Fix Released Status in Light Display Manager 1.6 series: Fix Released Status in Light Display Manager 1.7 series: Fix Released Status in “lightdm” package in Ubuntu: Fix Released Status in “lightdm” source package in Raring: Fix Released Status in “lightdm” source package in Saucy: Fix Released Bug description: Impact: If a users X authority file contains invalid data the user will not be able to log in with LightDM until the file is corrected or removed. The reason for the corruption has not been identified. To reproduce: 1. Stop lightdm $ sudo stop lightdm 2. Create an invalid X authority file in the home directory of a user, e.g. from a text VT: $ cp /etc/hostname ~/.Xauthority 3. Start lightdm $ sudo start lightdm 4. Log into the user account in the greeter Expected result: Logged into graphical session. Observed result: Returned to greeter, graphical session not shown. Regression potential: Change is small and was a regression in 1.6 due to accidental removal line resetting the error variable after reading the existing X authority file. Seems unlikely to cause any side-effects. To manage notifications about this bug go to: https://bugs.launchpad.net/lightdm/+bug/1234400/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp
