drm/xe: Make dma-fences compliant with the safe access rules
At a glance
Severity
HIGH 7.8
EPSS
EPSS 0.17 % · percentile 6 (2026-10-27)
State
PUBLISHED
Published
Updated
Assigner
Linux
NVD status
Modified
Description
In the Linux kernel, the following vulnerability has been resolved:
drm/xe: Make dma-fences compliant with the safe access rules
Xe can free some of the data pointed to by the dma-fences it exports. Most
notably the timeline name can get freed if userspace closes the associated
submit queue. At the same time the fence could have been exported to a
third party (for example a sync_fence fd) which will then cause an use-
after-free on subsequent access.
To make this safe we need to make the driver compliant with the newly
documented dma-fence rules. Driver has to ensure a RCU grace period
between signalling a fence and freeing any data pointed to by said fence.
For the timeline name we simply make the queue be freed via kfree_rcu and
for the shared lock associated with multiple queues we add a RCU grace
period before freeing the per GT structure holding the lock.
