Kees Cook

Cook came out of Ubuntu's security team and wrote Yama, the security module behind ptrace_scope, which stops a process from reading its siblings' memory. He has long been one of the maintainers of seccomp.

In 2015 he launched the Kernel Self Protection Project on a sober premise: the Linux kernel will always have bugs, so it had better make them harder to exploit. Much of what grsecurity/PaX had offered out of tree for years came upstream as reworked, smaller pieces that could actually get merged — slower, but that is the code running on billions of devices.