CVE-2024-44956

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> drm/xe/preempt_fence: enlarge the fence critical section<br /> <br /> It is really easy to introduce subtle deadlocks in<br /> preempt_fence_work_func() since we operate on single global ordered-wq<br /> for signalling our preempt fences behind the scenes, so even though we<br /> signal a particular fence, everything in the callback should be in the<br /> fence critical section, since blocking in the callback will prevent<br /> other published fences from signalling. If we enlarge the fence critical<br /> section to cover the entire callback, then lockdep should be able to<br /> understand this better, and complain if we grab a sensitive lock like<br /> vm-&gt;lock, which is also held when waiting on preempt fences.