drm/xe: Guard page-fault worker with runtime PM check

Summary

In the Linux kernel, the following vulnerability has been resolved: drm/xe: Guard page-fault worker with runtime PM check During VM teardown, the VM's runtime PM reference is dropped asynchronously, allowing the device to autosuspend while stale page faults belonging to the now-dead VM are still queued. When the page-fault worker later tries to ack one of these, it calls into guc_ct_send_locked() on an already-suspended device, tripping:   Assertion `!xe_pm_runtime_suspended(xe)` failed!   WARNING at xe_device.c:1267 xe_device_assert_mem_access+0x11c/0x140 [xe] A live VM/exec queue always holds a PM reference while it has outstanding work, so if the device is suspended at ack time, the owning context is already gone and the fault is stale. Take a runtime PM reference across the entire pagefault queue worker to safely deliver acks for torn-down VMs. v3: • Move PM ref to the generic xe_pagefault_queue_work using guard(xe_pm_runtime)(xe) instead of tracking it in the GuC backend(Matt Brost). v2: • Hold PM ref across the entire batch (begin/end) instead of per-ack. This prevents the device from autosuspending mid-batch, which would leave write_only acks written but the end flush skipped, and skip counter++, desyncing the cadence check.(Himal) • Add a comment explaining stale faults.(Himal) (cherry picked from commit fcc2431d2213dc4d04250c4f1ae87d9c3ae0d455) [Rodrigo: Added xe_device struct for compatibility while cherry-picking]

Timeline

1. Oct 14, 2026, 1:25 PM UTCCVE published
2. Oct 19, 2026, 9:18 AM UTCRecord last updated

Affected versions

• Linux Linux

  From f289f7807119128d4f9d59f34ac557549c7562e5 · fixed in 25764620ec64c0142e2c87c41787f45540cf09ff; From f289f7807119128d4f9d59f34ac557549c7562e5 · fixed in 20fce5b34b21a995839743b4917a1edd2fd503ba

• Linux Linux

  6.19

• KernelLinux

  From 6.19.0 · fixed in 7.2.7

References 2