Kernel Vulnerability in Linux Affecting PCI BAR Configuration

CVE-2026-64254

What is CVE-2026-64254?

A vulnerability in the Linux kernel occurs when the BAR_PEER_SPAD and BAR_CONFIG share a single PCI BAR. This leads to unnecessary calls to pci_iounmap() on the same I/O memory with an offset during the module teardown process. This can trigger kernel warnings indicating attempts to unmap nonexistent virtual memory areas. The problem arises specifically in scenarios where the two configurations access the same BAR, and the resolution requires ensuring unmapping only occurs when they operate on different memory addresses. Properly addressing this vulnerability enhances the stability and reliability of Linux kernel operations.

References