I was migrating a CVS repository from one server to another today and ran on the interesting issue. I was getting a “Permission denied” error on the CVSROOT/config file no matter what privileges were set. It turns out that problem is with SELinux on CentOS, so the easiest solution is to just turn it off.
/usr/sbin/setenforce 0
If you want to be sure that it will be turned off after the server restart, just edit the /etc/sysconfig/selinux file and set SELINUX to permissive