I read or heard somewhere (maybe in LinuxCBT's SELinux course; but I'm not sure) that there are online Linux servers, for which the password of the root user is also given. The Linux server is hardened using SELinux rules, such that everyone can login with the root user, but cannot make any harm to the OS.
It seems like a myth to me, but I wanted to make sure: Is it possible to harden a Linux box (possibly with SELinux), such that even the root user cannot do specific malicious activities on it? (Examples: deleting system files, clearing log files, stopping critical services, etc.)
Such a Linux box will be a great starting point for building a honeypot.
Edit: Based on an answer (now deleted), and a little Googling, I got at least two links which pointed out to such hardened Linux servers. Unfortunately, both servers are down. For the record, I'll copy-paste the descriptions here:
Free root access on a SE Linux machine!
To access my Debian play machine ssh to play.coker.com.au as root, the password is ...
Note that such machines require a lot of skill if you are to run them successfully. If you have to ask whether you should run one then the answer is "no".
The aim of this is to demonstrate that all necessary security can be provided by SE Linux without any Unix permissions (however it is still recommended that you use Unix permissions as well for real servers). Also it gives you a chance to login to a SE machine and see what it's like.
When you login to a SE Linux play machine make sure that you use the -x option to disable X11 forwarding or set ForwardX11 no in your /etc/ssh/ssh_config file before you login. Also make sure that you use the -a option to disable ssh agent forwarding or set ForwardAgent no in your /etc/ssh/ssh_config file before you login. If you don't correctly disable these settings then logging in to the play machine will put you at risk of being attacked through your SSH client.
There is an IRC channel for discussing this, it is #selinux on irc.freenode.net.
Here is a quick FAQ
Hardened Gentoo's purpose is to make Gentoo viable for high security, high stability production server environments. This project is not a standalone project disjoined from Gentoo proper; it is intended to be a team of Gentoo developers which are focused on delivering solutions to Gentoo that provide strong security and stability. This machine is Hardened Gentoo's SELinux demo machine. The primary use of it is to test and audit SELinux integration, and policy.