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 constant archive, calls io_fput_file() which incorrectly decrements its reference count. The constants archives they are permanently registered and should not be operated 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 the servers immediately and apply them patches for other distributions as they become available. It is also recommended that they only allow access to local systems to trusted users and always monitor their systems.
