I ran into an issue re-enabling SELinux on my little fleet of CentOS 7 boxes in my home lab. Basically when I installed them I had disabled SELinux at install and thus enabling SELinux was causing all the systems to freeze up after a reboot.
A little googling/digging around mailing lists. I stumbled upon a post that gave a perfect answer to fix the problem I was having.
yum remove selinux-policy\*
rm -rf /etc/selinux/targeted /etc/selinux/config
yum install selinux-policy-targeted
yum install selinux-policy-devel policycoreutils-gui
### *^*^*^ Only if these were removed by the yum remove.
touch /.autorelabel; reboot
Basically temporary disable SELinux, remove selinux-policy*, remove the old targeted dir and config file, and re-install selinux. Followed by the usualy autorelabel and reboot.
The only thing I would add would be to check your network and ifup the interface after setenforce 0.