CVE-2023-54042

A flaw was found in the Linux kernel on PowerPC 64-bit systems. In the Virtual Accelerator Switchboard (VAS) subsystem, the memory descriptor (mm) reference count is dropped before the coprocessor is properly detached. This ordering error can lead to a use-after-free condition when the mm structure is accessed after being freed.

This vulnerability is specific to PowerPC 64-bit server systems (powerpc/64s) using the VAS coprocessor interface. Most deployments on other architectures are not affected. The issue requires local access and use of VAS acceleration features, significantly limiting the attack surface.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.