Their modified kernel tarball, yes. The idea is if you create a forked version that instead is malware, that intercepts everything that happens on the computer and sends it off to an adversary, that trademark protections allow the original author of the non-malicious software to say you can't call it by the name that I'm using for my product because you've changed it and it's malicious now.

Trademark law is the most reasonable leg of the intellectual property triad, in my opinion.

No, don't think so. But he can force you to call it "Carrot" in all marketing materials. Although you have to state it's a modification of "Linux" because of the GPL :)