You can use stuff like https://github.com/dynup/kpatch https://github.com/dynup/kpatch or http://www.ksplice.com/ http://www.ksplice.com/ to apply security patc

You can use stuff like https://github.com/dynup/kpatch https://github.com/dynup/kpatch or http://www.ksplice.com/ http://www.ksplice.com/ to apply security patches to a running Linux kernel, but that's still pretty new stuff. Stratus has been doing that since the 90s, though :-)