Information
Configure SELINUX to be enabled at boot time and verify that it has not been overwritten by the grub boot parameters.
Note: This recommendation is designed around the grub 2 bootloader, if LILO or another bootloader is in use in your environment enact equivalent settings.
Rationale:
SELinux must be enabled at boot time in your grub configuration to ensure that the controls it provides are not overridden.
Solution
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:
# grub2-mkconfig -o /boot/grub2/grub.cfg