This is a very clever piece of work. It looks like innocuous error checking, but it’s really a back door. And it was slipped into the code outside the normal approval process, to avoid any possibility that the approval process would notice what was up.Me, I'm not so worried about stupid hackers. I lose sleep at night over really smart ones. They really are out to get you, and are very good at flying below the radar.
But the attempt didn’t work, because the Linux team was careful enough to notice that that this code was in the CVS repository without having gone through the normal approval process. Score one for Linux.
Could this have been an NSA attack? Maybe. But there were many others who had the skill and motivation to carry out this attack. Unless somebody confesses, or a smoking-gun document turns up, we’ll never know.
If I come across as paranoid, remember that I was professionally trained to be that way by the Finest Minds in the Free World.