That’s a crazy “if”
I’m genuinely worried sometimes that a Ken hack has been introduced. I don’t know by who, but possibly some government agency. Then again, we also have a Minix system built into the CPU doing god knows what and we just accept that.
That is actually perfectly reasonable assumption to make in the absence of resources to determine the opposite, which would probably be many times the resources needed to actually fix the bug.
There are lots of things the Kernel controls that can have non security related bugs, e.g. controller with the wrong mapping https://github.com/torvalds/linux/commit/9131f8cc2b4eaf7c08d402243429e0bfba9aa0d6
It’s a wild assumption to claim “All bugs in the Linux kernel are security issues”, without any backing, whoever is making that claim needs to provide evidence since the default position for any program is that there are bugs that are not security issues.