Failed to Load SELinux Policy

After a failed yum upgrade (darn low memory) I noticed my CentOS NTP server was not booting anymore. Look at console showed progress bar still loading but pressing Escape showed the real issue: Failed to load SELinux policy, freezing.

The first thing in that situation is to try booting without SELinux and the easiest way I found to accomplish this was pressing e on boot menu and then adding selinux=0 at the end of line starting with linux16. Continuing boot with Ctrl+X will load CentOS but with SELinux disabled.

As I actually don't run my public-facing servers without SELinux, it was time to fix it. Since I didn't have package before, I installed selinux-policy-targeted but I would equally use reinstall if package was already present. In any case, running both doesn't hurt:

Terminal  Copy
sudo yum install -y selinux-policy-targeted
sudo yum reinstall -y selinux-policy-targeted

Finally we need to let system know SELinux should be reapplied. This can be done by creating a special .autorelabel file in the root directory followed by a reboot:

Terminal  Copy
sudo touch /.autorelabel
sudo reboot

During reboot SELinux will reapply all labeling it needs and we can enjoy our server again.