Comment by dec0dedab0de

yes, of course, and I'm fairly certain it's happened before or at least there have been suspicions of it happening. Thats why trust is important, and why I'm glad kernel development is not very friendly.

Doing code review at work I am constantly catching blatantly obvious security bugs. Most developers are so happy to get the thing to work, that they don't even consider security. This is in high level languages, with a fairly small team, only internal users, and pretty simple code base. I can't imagine trying to do it for something as high stakes and complicated as the kernel. Not to mention how subtle bugs can be in C. I suspect it is impossible to distinguish incompetence from malice. So aggressively weeding out incompetence, and then forming layers of trust is the only real defense.