I have an OpenSuSE 12.3 machine and can't login to the box either on tty or via ssh. As soon as the user logs in the session terminates and in the message "login  permission denied" is printed.
The machine was set to autologin on KDE so that user autologs-in
[Update] I am not sure what has changed on the system, I am not the only one who has access to the box and according to everybody nothing has changed. The only thing that went wrong on the system was that it takes a backup of a DB on a different machine and there wasn't any space on it. I cleared all the space after some googling updated PAM, that solved the problem but then the problem repeated when I check the system there wasn't any space again, cleared the system re-installed PAM to no avail. Upgraded the system from 12.1 to 12.3 but didn't help.
There isn't a /var/log/secure log. The only relevant message is permission denied
users are not locked on KDE I can login with any user but not on tty or ssh, can su/sudo
There are lot of files in /etc/pam.d/ which one do I need to check [/Update]