Information
SELinux must be enabled at boot time in your grub configuration to ensure that the controls it provides are not overridden.
Solution
For grub2 based systems edit /etc/default/grub and remove all instances of selinux=0 and enforcing=0 from all CMDLINE_LINUX parameters:
GRUB_CMDLINE_LINUX_DEFAULT='quiet'
GRUB_CMDLINE_LINUX=''
Run the following command to update the grub2 configuration: # update-grub