I'm not seeing the patch in 4.20.11's changelog or any of the longterm kernel versions posted today.
It's trivial to apply yourself, though from https://github.com/torvalds/linux/commit/9060cb719e61b685ec0...
curl https://github.com/torvalds/linux/commit/9060cb719e61b685ec0102574e10337fa5f445ea.patch | git am
(Or `| patch -p1` if you don't have a git checkout of the kernel tree.)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.