> It could never be licensed in a way that prevented the patch set or the resulting patched kernel source/binaries from being covered and distributed under the GPLv2. If that were the case, the kernel would effectively not be covered by the GPL at all.

Is this true? I would think that as long as your "new" code is sufficiently distinct from the stuff you're replacing, you'd be fine distributing a non-GPL patch (at least if it's e.g. purely positional to elide context related issues). The result of applying the patch would not be distributable, but I'd think the patch itself would be fine.