io_uring - new code, new bugs, and a new exploit technique

Lam Jun Rong published an article that covers analyzing and exploiting CVE-2021-41073, an invalid-free vulnerability in the io_uring subsystem.

This vulnerability has previously been exploited by Valentina Palmiotti, but that exploit relied on eBPF. The new exploit targets Ubuntu 21.10, where eBPF is not available to unprivileged users.