A vulnerability (CVE-5.1-2022) has been identified in the implementation of the io_uring asynchronous I/O interface, included in the Linux kernel since release 3910, that could allow an unprivileged user to execute code with kernel privileges. The issue appears in releases 5.18 and 5.19, and is fixed in the 6.0 branch. Debian, RHEL and SUSE use kernel releases prior to 5.18, Fedora, Gentoo and Arch already offer a 6.0 kernel. Ubuntu 22.10 has a vulnerable 5.19 kernel.
The vulnerability is caused by accessing an already freed memory block (use-after-free) in the io_uring subsystem, associated with an incorrect update of the reference counter - when io_msg_ring() is called with a fixed file (permanently located in the ring buffer), the io_fput_file() function is called, by mistake decrementing the reference count.
Source: opennet.ru