I literally just compiled 4.20.11 for Slackware.
I swear these things are popping up more often. Or more likely since spectre I've just been paying more attention
syzkaller.appspot.com should give you an idea how many THOUSANDS of these types of bugs exist in the current ToT kernel
Maybe the answer is to do a daily automated recompilation of the kernel, rebuild of the edge LB and FW images followed by automated, staged rollout and rollback. If we're vulnerable anyway, let's just pick up the fixes from yesterday at least and roll back if things go wrong. That sounds really scary, but doable.