CVE-2024-44956: drm/xe/preempt_fence: enlarge the fence critical section

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-09-04 · updated 2026-06-17
Weakness: CWE-667

Description

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

Affected products

Linux kernel: before 6.10.5 — fixed in 6.10.5

How to fix

Upgrade to a fixed version: Linux kernel 6.10.5. Check the vendor advisory for mitigations.

References

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