Because Linus signed off on it. To get that complex change into the kernel, the NSA had to convince Linus that it's a good idea, which can be a next-to-impossible task. I trust him to review the code more than I trust myself.
Linus doesn't review everything. He delegates and trusts.
That's tangential, though. More importantly, I expect NSA contributions to be poured over because the NSA isn't highly trusted, and it would make a great mailing list post to say "The NSA has a backdoor in our code here, here, and here."
Many eyes and a suspect contributor make all backdoors shallow.
That's tangential, though. More importantly, I expect NSA contributions to be poured over because the NSA isn't highly trusted, and it would make a great mailing list post to say "The NSA has a backdoor in our code here, here, and here."
Many eyes and a suspect contributor make all backdoors shallow.