CVE-2026-64042

In the Linux kernel, the following vulnerability has been resolved:

vfio/pci: Check BAR resources before exporting a DMABUF

A DMABUF exports access to BAR resources and, although they are requested at startup time, we need to ensure they really were reserved before exporting. Otherwise, it's possible to access unreserved resources through the export.

Add a check to the DMABUF-creation path.