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

drm/nouveau: Fix WARN_ON in nouveau_fence_context_kill()

Nouveau is mostly designed in a way that it's expected that fences only
ever get signaled through nouveau_fence_signal(). However, in at least
one other place, nouveau_fence_done(), can signal fences, too. If that
happens (race) a signaled fence remains in the pending list for a while,
until it gets removed by nouveau_fence_update().

Should nouveau_fence_context_kill() run in the meantime, this would be
a bug because the function would attempt to set an error code on an
already signaled fence.

Have nouveau_fence_context_kill() check for a fence being signaled.

https://git.kernel.org/stable/c/0453825167ecc816ec15c736e52316f69db0deb9

https://git.kernel.org/stable/c/126f5c6e0cb84e5c6f7a3a856d799d85668fb38e

https://git.kernel.org/stable/c/2ec0f5f6d4768f292c8406ed92fa699f184577e5

https://git.kernel.org/stable/c/47ca11836c35c5698088fd87f7fb4b0ffa217e17

https://git.kernel.org/stable/c/b771b2017260ffc3a8d4e81266619649bffcb242

https://git.kernel.org/stable/c/bbe5679f30d7690a9b6838a583b9690ea73fe0e9