(Note: last month the GRSecurity Team removed the public testing
patch,
they prevent the distribution of the patch by paying customers by a
threat of no further business: they have concocted a transparent scheme
to make sure the intention of the Linux rights-holders (thousands of
entities) are defeated) (This is unlike RedHat who do distribute their
patches in the form the rights-holders prefer: source code, RedHat does
not attempt to stymie the redistribution of their derivative works,
GRSecurity does.).
I don't think Red Hat distributes the Red Hat Enterprise Linux 7
kernels to the general public, only to customers who have entered a
subscription agreement. Debranded kernel sources are available from
centos.org, though.
Based on what I have read, the legal construction for the Red Hat
agreement and the grsecurity agreement are somewhat similar. Source
code access is a subscription service (among many others in the case
of Red Hat), and you cannot use a subscription to provide the very
same service you obtain from the provider to third parties.
The situation with Red Hat Enterprise Linux is further complicated
because as part of the subscription services, subscribers can access
the Red Hat Code Browser, which provides broken-out and fully
cross-referenced kernel patches, something that is not available as
part of the CentOS offering. The GPL certainly allows subscribers to
share these patches freely (and almost all of them are just backports
from upstream anyway), but I think Red Hat's intent is that this is
not permitted while the subscription agreement is in force. (And
subscribers are expected not to use these patches to support their own
kernel backporting efforts, either.)