CVE-2026-52951 drm/xe/dma-buf: handle empty bo and UAF races

In the Linux kernel, the following vulnerability has been resolved: drm/xe/dma-buf: handle empty bo and UAF races There look to be some nasty races here when triggering the invalidatemappings hook: 1 We do xeboalloc followed by the attach, before the actual full bo init step in xedmabufinitobj...