This bug isn't related to SELinux (it appears with SELinux enabled,
disabled and permissive). Additionally, the ability to shut down the
computer as a regular user is only available to local logins, meaning it
is an almost non-existent security problem. If a user has physical
access to the computer, they have complete control of the computer.
Allowing them to shutdown and reboot becomes a data integrity issue at
that point (if a user, present at the console, cannot restart the
computer in the "proper" way, they can *always* power cycle it.) All of
that being said, the "unknown user" bug is really irritating ...
--
Shahms King <shahms(a)shahms.com>