Recently Redhat announced the vulnerability CVE-2022-3910 (CVSS score: 7.4) in the Linux kernel. This is a bug in updating the Reference Count in io_uring.
io_uring is a system call interface for Linux. It first came in version 5.1 of the Linux kernel in 2019. It allows an application to initiate system calls that can be executed asynchronously.
In the Linux kernel, an incorrect reference count update to io_uring leads to Use-After-Free and local privilege escalation. When io_msg_ring is called with a fixed file, it calls io_fput_file() which incorrectly decrements its reference count. Fixed files are permanently registered and should not be run separately.
Bug CVE-2022-3910 was fixed a few hours ago.
Currently, the kernel developers have released an official security update.
Users are advised to update servers immediately and apply patches for others distributions as soon as these are available. It is also recommended to enable the access on local systems only to trusted users and always monitor their systems.