CVE-2023-52654: 
Linux Kernel vulnerability analysis and mitigation

A security vulnerability (CVE-2023-52654) was identified in the Linux kernel's io_uring subsystem, specifically related to the handling of file descriptors over UNIX domain sockets. The vulnerability was discovered when file reference cycles caused problems with io_uring, particularly involving the transmission of io_uring file descriptors over sockets using the SCM_RIGHTS mechanism (Red Hat Portal).

The vulnerability stems from potential file reference cycles when io_uring file descriptors are transmitted over sockets using the SCM_RIGHTS mechanism. These cycles can lead to resource leaks and race conditions, particularly with the unix_stream_read_generic() function. The vulnerability has been assigned a CVSS v3 Base Score of 5.5 (Moderate) with the following vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H (Red Hat Portal).

The vulnerability can result in resource leaks and race conditions in the Linux kernel's io_uring subsystem. The impact is primarily focused on availability, with no direct effect on confidentiality or integrity of the system (Red Hat Portal).

The vulnerability requires local access with low privileges and no user interaction. The attack complexity is considered low, making it relatively straightforward to exploit if an attacker has the necessary local access (Red Hat Portal).

The vulnerability has been resolved by completely disallowing the sending of io_uring files via sockets through SCM_RIGHTS. This fix eliminates the possibility of cycles involving registered files and removes the need for SCM accounting on the io_uring side (Kernel Git).