If you can access AF_ALG on a server you don't need to do shenanigans like that. It's much easier to just find another bug and exploit that one instead.
The copy.fail website is very silly, it is not a special bug. If anyone gets compromised by that vuln their node architecture was broken anyway, patching copy.fail doesn't help.
I thought copy.fail is a privelage escalation exploit, become root from a regular user? Am I missing something?
How would "node architecture" make people vulnerable to this?
You have to have shell access to a victim first right? Or am I missing something?
In what way is it "not a special bug"? It's a publicly known root access from RCE exploit. Those cannot be a dime a dozen. I'm sure it's especially interesting for any shared hosting services which might be affected, and could be delayed. I could find any places running containered services and exfiltrate secrets parallel services, no?
What constitutes "special" for you, out of curiosity? Something chaining with a hypervisor exploit?