That'd be the joy of their paralegal auditing team's life for the next year to figure out: does all of the code that they're building into their version of the

That'd be the joy of their paralegal auditing team's life for the next year to figure out: does all of the code that they're building into their version of the kernel include the "either version 2 of the License, or (at your option) any later version" clause, such that the resulting binary can be a legal GPLv3 binary? I haven't a clue. The GRsec people wouldn't care, their patch can be whatever GPLv2-compatible license it wants to be.