A vulnerability in the Linux kernel s390 per-CPU operations can lead to memory corruption or exception handling failures, necessitating an immediate update to version 7.2.4 or later.

This flaw involves an assembler macro invocation error in the MVIY_PERCPU function that fails to execute correctly when using older binutils versions. The failure prevents the kernel from properly marking interrupted per-CPU sequences, which can prevent the exception return path from correctly repairing the per-CPU address register.

While the CVSS score of 7.0 reflects a high severity, the requirement for local, authenticated access and specific assembler conditions limits the immediate scope. However, successful exploitation could lead to privilege escalation or system instability, as the kernel cannot properly handle exceptions or maintain address register integrity. This poses a significant risk to the reliability and security of systems running sensitive workloads on the s390 architecture.

Immediate Action: Update the Linux kernel to version 7.2.4 or later to ensure the MVIY_PERCPU macro is correctly parsed and executed.

Proactive Monitoring: Monitor system logs for unexpected kernel warnings or migration-related exceptions that may indicate underlying memory or register issues.

Compensating Controls: Ensure that systems are compiled with modern binutils versions, as older versions are the primary trigger for this assembler parsing failure.

Public Exploit Available: Unknown

This vulnerability represents a critical failure in low-level kernel operations that could compromise system stability. Administrators managing Linux environments on s390 architecture should prioritize patching to version 7.2.4 or higher. Given the nature of the flaw, verifying that the kernel is built with current versions of binutils is an essential secondary measure to prevent similar parsing failures in the future.