IOMMU Vulnerability in Linux Kernel Affecting s390 Hypervisor Operations

CVE-2025-39958

What is CVE-2025-39958?

A vulnerability exists in the Linux kernel where the IOMMU subsystem does not properly handle surprise removal of PCI devices. When such devices are removed unexpectedly, attempts to attach them to the default domain can fail, leading to potential operational disruptions in the hypervisor environment. This situation can result in invalid device handles being processed, causing errors in DMA operations. By ensuring that the system proceeds as though the registration was successful, despite the removal, the vulnerability aims to enhance stability and error handling for s390 devices in hypervisor environments.

References