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.
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