s390/fpu Vulnerability in Linux Kernel Affecting IBM Products

CVE-2025-68751

What is CVE-2025-68751?

The Linux kernel's s390/fpu subsystem has identified a reliability issue related to inline assembly instructions that can lead to false-positive reports from the kernel memory sanitizer (KMSAN). Specifically, the 'vstl' instruction's behavior varies based on the runtime value of the 'index' argument, potentially leading to incorrect memory access reports. This vulnerability has been addressed by updating the memory sanitizer's write helper calls to reflect the accurate byte size written, effectively mitigating misleading KMSAN alerts. Users should ensure they have the latest patches applied to improve the stability and security of their systems.

References