Alma Linux: CVE-2024-41092: Moderate: kernel security update (Multiple Advisories)

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

drm/i915/gt: Fix potential UAF by revoke of fence registers

CI has been sporadically reporting the following issue triggered by
igt@i915_selftest@live@hangcheck on ADL-P and similar machines:

...
active))
...
...

...
...

In the past, there were similar failures reported by CI from other IGT
tests, observed on other platforms.

Before commit 63baf4f3d587 ("drm/i915/gt: Only wait for GPU activity
before unbinding a GGTT fence"), i915_vma_revoke_fence() was waiting for
idleness of vma->active via fence_update(). That commit introduced
vma->fence->active in order for the fence_update() to be able to wait
selectively on that one instead of vma->active since only idleness of
fence registers was needed. But then, another commit 0d86ee35097a
("drm/i915/gt: Make fence revocation unequivocal") replaced the call to
fence_update() in i915_vma_revoke_fence() with only fence_write(), and
also added that GEM_BUG_ON(!i915_active_is_idle(&fence->active)) in front.
No justification was provided on why we might then expect idleness of
vma->fence->active without first waiting on it.

The issue can be potentially caused by a race among revocation of fence
registers on one side and sequential execution of signal callbacks invoked
on completion of a request that was using them on the other, still
processed in parallel to revocation of those fence registers. Fix it by
waiting for idleness of vma->fence->active in i915_vma_revoke_fence().

(cherry picked from commit 24bb052d3dd499c5956abad5f7d8e4fd07da7fb1)