If a user with a world-writeable directory tries to log in, gdm will accept their password, clear the screen as if to start the session, and then immediately kill the session and return to the login box. No error messages are presented, and we couldn't even find any explanation in a log file anywhere. I'm not sure if the bug is in gdm itself or the login scripts that Redhat 6.0 uses. I have also submitted this as a Gnome bug.
This is listed as Gnome bug report #1393
I have verified this to be true on a test lab machine with a stock 6.0 intall. I created a sample user account. chmod 777 that users home directory. Then using gdm attempted to login as the sample user with out success. It would come back to the gdm login screen. I then chmod 755 the home directory and then was able to successfully login to the gnome desktop.
This might just be a good security measure - with xauth style security, a world-writeable home directory is a really bad idea. If this is correct behaviour, then the "fix" should be to make sure the user understands why they weren't allowed to log in. Some sort of visible error message...
Assign to mkj for now.
Try getting the gdm-2.0beta2-13 from RHL 6.1