"We developed an exploit that allows unprivileged local users to start a root shell by abusing the above issue. That exploit was shared privately with <security () kernel org> to assist with fix development. Somebody from the Linux kernel team then emailed the proposed fix to <linux-distros () vs openwall org> and that email also included a link to download our description of exploitation techniques and our exploit source code.

Therefore, according to the linux-distros list policy, the exploit must be published within 7 days from this advisory. In order to comply with that policy, I intend to publish both the description of exploitation techniques and also the exploit source code on Monday 15th by email to this list."

Interesting.. they didn't write what conditions have to be met for it to be exploitable. Also interesting that someone screwed up and accidentally forwarded an email including the exploit to a broad mailing list...

Part of the nf modules are active if you have iptables, which you have if you run ufw (for example), so pretty broad exploit if that's all that's required, but the specific module in question in the patch, nf_tables, is not loaded on my Ubuntu 20.04LTS 5.40 kernel running iptables/ufw at least.