"SELinux, also known as Security Enhanced Linux, is a
National Security Agency sponsored Linux project to develop a more
secure Linux. SELinux is a set of Linux kernel patches and
utilities designed around a usable but mandatory access control
system.
Using SELinux will require a recompile of either a stock Linux
2.4.12 (at the time of this writing) kernel, with patches, or the
downloading of the SELinux kernel distribution from the SELinux Web
site (see resources below). The SELinux kernel distribution is
available in several download forms. I chose the 34-megabyte
package that includes Linux 2.4.12 already patched for SELinux, and
the associated software utilities needed to operate SELinux. Our
installation box is a stock Red Hat 6.2 machine with all relevant
updates.
I am not going to go into the re-compilation of the kernel. If
you are attempting to run SELinux, I'm sure that you have already
recompiled your kernel ad nauseum. However, I will say that it is
important to view the README files within the selinux directory
that is created after unpacking the source package. Once you have
read these files, recompiling the Linux kernel for the provided
features is a snap."