> What happens when a security bug stops the ventilating machine of a person lying in hospital bed, or halts the screen of a surgeon.

Linux is not a kernel for this kind of uses. Whoever does it, is doing a disservice to the people.

Operating systems like INTEGRITY RTOS or similar, are the only ones able to match the security quality requirements for such deployments.

https://www.ghs.com/products/rtos/integrity.html