drm/i915/gt: Unmask interrupts only when ACTIVE is true
Summary
| CVE | CVE-2026-99005 |
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| State | PUBLISHED |
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| Assigner | Linux |
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| Source Priority | CVE Program / NVD first with legacy fallback |
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| Published | 2026-10-23 13:17:22 UTC |
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| Updated | 2026-10-23 13:17:22 UTC |
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| Description | In the Linux kernel, the following vulnerability has been resolved:
drm/i915/gt: Unmask interrupts only when ACTIVE is true
There is a small race window between intel_rps_boost() reading
a stale ACTIVE state and queuing rps->work, where ACTIVE may be
changed via asynchronous calls triggered by wakeref drop.
This means that rps_work() could be triggered after the GT has
been parked, so unmasking RPS PM interrupts would happen without
holding PM wakelock. This sequence of events may be observed
during live_rc6_ctx_wa() selftest:
1) live_rc6_ctx_wa()
-> intel_engine_pm_put()
-> wakeref_put()
ASYNC1) wakeref_put() callback
-> __engine_park()
-> intel_gt_pm_put_async()
-> intel_gt_pm_put_async_untracked()
-> intel_wakeref_put_async()
ASYNC2) wakeref_put_async() callback
-> __gt_park()
-> intel_rps_park()
-> intel_rps_clear_active() [clear ACTIVE]
WITH INTERRUPTS:
-> rps_disable_interrupts()
-> cancel_work_sync(rps->work)
-> rps_reset_interrupts() [rps->pm_iir = 0]
WITHOUT INTERRUPTS (TIMER mode):
-> rps_stop_timer()
-> cancel_work_sync(rps->work)
2) live_rc6_ctx_wa()
-> intel_gt_wait_for_idle()
-> intel_gt_retire_requests_timeout()
-> dma_fence_wait_timeout()
-> ops->wait() [i915_fence_wait()]
-> i915_request_wait_timeout()
-> intel_rps_boost()
-> intel_rps_is_active() [check ACTIVE]
[OPEN RACE WINDOW]
-> queue_work(rps->work)
-> retire_requests()
-> i915_request_retire()
-> intel_rps_dec_waiters() [from 1 to 0]
If ASYNC1 and ASYNC2 would execute during [OPEN RACE WINDOW],
then:
3) rps_work() executes from the workqueue and may satisfy
"(!pm_iir && !client_boost)" test (in TIMER mode rps->pm_iir
is zeroed by an earlier rps_work() call or never gets a new
value after previous intel_rps_unpark() event), so it jumps
to "out" label, bypassing intel_rps_is_active() guard and
executes gen6_gt_pm_unmask_irq();
4) GT is parked and runtime PM wakelock is dropped, so only
a raw reference in __gt_park() ->
intel_display_power_put_async() remains for 100ms, then the
MMIO write in gen6_gt_pm_unmask_irq() detects missing
wakelock via assert_rpm_wakelock_held() and emits
"RPM wakelock ref not held during HW access" tainting kernel.
Commit 3e7abf814193 ("drm/i915: Extract GT render power state management")
dropped the "if (rps->interrupts_enabled)" guard that
gen6_pm_rps_work() had around this unmask in i915_irq.c.
INTEL_RPS_ACTIVE brackets the same window, since it is set in
intel_rps_unpark() before rps_enable_interrupts() and
rps_start_timer() and cleared in intel_rps_park() before
rps_stop_timer() and rps_disable_interrupts().
Skip unmasking when RPS is no longer active (reaching unmask
operation is independent of INTERRUPT mode). This does not
prevent RPS operation from resuming on the next unpark.
In interrupt mode, intel_rps_unpark() calls
rps_enable_interrupts(), which enables and unmasks the PM
interrupts. In timer mode, it calls rps_start_timer(),
restarting periodic engine-busyness evaluation. The timer
generates software RPS events and queues rps_work() directly,
independently of PM interrupt delivery. Neither mode requires
the late worker to unmask interrupts while the GT is parked
(cherry picked from commit ca4a6deadad15b91ee083afe445fa6bdbfb68206) |
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Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|
| CNA |
Linux |
Linux |
affected 3e7abf8141935ded77abeb622480bf4a14241ece 77abc1837c9651c8f43f7f7f336d10093eeb7745 git |
Not specified |
| CNA |
Linux |
Linux |
affected 3e7abf8141935ded77abeb622480bf4a14241ece 60f58da15f8c8e39706c564f9251de3626636dce git |
Not specified |
| CNA |
Linux |
Linux |
affected 3e7abf8141935ded77abeb622480bf4a14241ece 0b4a0fb98b9ffeac36798bbd369c821605cae70f git |
Not specified |
| CNA |
Linux |
Linux |
affected 3e7abf8141935ded77abeb622480bf4a14241ece 49d349c42cf5ebaa878d02699c632c9d883d935f git |
Not specified |
| CNA |
Linux |
Linux |
affected 3e7abf8141935ded77abeb622480bf4a14241ece 5346b1cec6afa4f9b4b49a9f84e3cfef95a3f7bb git |
Not specified |
| CNA |
Linux |
Linux |
affected 5.5 |
Not specified |
| CNA |
Linux |
Linux |
unaffected 5.5 semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.6.160 6.6.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.12.113 6.12.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.18.57 6.18.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 7.2.11 7.2.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 7.3 * original_commit_for_fix |
Not specified |
References
| Reference | Source | Link | Tags |
|---|
| git.kernel.org/stable/c/77abc1837c9651c8f43f7f7f336d10093eeb7745 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/0b4a0fb98b9ffeac36798bbd369c821605cae70f |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/60f58da15f8c8e39706c564f9251de3626636dce |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/5346b1cec6afa4f9b4b49a9f84e3cfef95a3f7bb |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/49d349c42cf5ebaa878d02699c632c9d883d935f |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| CVE Program record |
CVE.ORG |
www.cve.org |
canonical |
| NVD vulnerability detail |
NVD |
nvd.nist.gov |
canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.