CVE-2025-40166: Linux Vulnerability (CVSS 7.8)

Description

In the Linux kernel, the following vulnerability has been resolved: drm/xe/guc: Check GuC running state before deregistering exec queue In normal operation, a registered exec queue is disabled and deregistered through the GuC, and freed only after the GuC confirms completion. However, if the driver is forced to unbind while the exec queue is still running, the user may call exec_destroy() after the GuC has already been stopped and CT communication disabled. In this case, the driver cannot receive a response from the GuC, preventing proper cleanup of exec queue resources. Fix this by directly releasing the resources when GuC is not running. Here is the failure dmesg log: " [ 468.089581] ---[ end trace 0000000000000000 ]--- [ 468.089608] pci 0000:03:00.0: [drm] *ERROR* GT0: GUC ID manager unclean (1/65535) [ 468.090558] pci 0000:03:00.0: [drm] GT0: total 65535 [ 468.090562] pci 0000:03:00.0: [drm] GT0: used 1 [ 468.090564] pci 0000:03:00.0: [drm] GT0: range 1..1 (1) [ 468.092716] ------------[ cut here ]------------ [ 468.092719] WARNING: CPU: 14 PID: 4775 at drivers/gpu/drm/xe/xe_ttm_vram_mgr.c:298 ttm_vram_mgr_fini+0xf8/0x130 [xe] " v2: use xe_uc_fw_is_running() instead of xe_guc_ct_enabled(). As CT may go down and come back during VF migration. (cherry picked from commit 9b42321a02c50a12b2beb6ae9469606257fbecea)

Metrics

CVSS 3.1

7.8/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

0.18%

8.0th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

Vendor	Product	Versions
Linux	Linux	>= dd08ebf6c3525a7ea2186e636df064ea47281987, < 2c6e5904c5bdbac8e0eadee40f70c42bb83f6dc6; >= dd08ebf6c3525a7ea2186e636df064ea47281987, < fa708415566bbe5361c935645107319f8edc8dc1; >= dd08ebf6c3525a7ea2186e636df064ea47281987, < 9f64b3cd051b825de0a2a9f145c8e003200cedd5
Linux	Linux	6.8

References

Timeline

Published: Nov 12, 2025
Last Modified: Jul 30, 2026
Status: Deferred

Frequently Asked Questions

What is CVE-2025-40166?

In the Linux kernel, the following vulnerability has been resolved: drm/xe/guc: Check GuC running state before deregistering exec queue In normal operation, a registered exec queue is disabled and deregistered through the GuC, and freed only after the GuC confirms completion. However, if the driver is forced to unbind while the exec queue is still running, the user may call exec_destroy() after the GuC has already been stopped and CT communication disabled. In this case, the driver cannot receive a response from the GuC, preventing proper cleanup of exec queue resources. Fix this by directly releasing the resources when GuC is not running. Here is the failure dmesg log: " [ 468.089581] ---[ end trace 0000000000000000 ]--- [ 468.089608] pci 0000:03:00.0: [drm] *ERROR* GT0: GUC ID manager unclean (1/65535) [ 468.090558] pci 0000:03:00.0: [drm] GT0: total 65535 [ 468.090562] pci 0000:03:00.0: [drm] GT0: used 1 [ 468.090564] pci 0000:03:00.0: [drm] GT0: range 1..1 (1) [ 468.092716] ------------[ cut here ]------------ [ 468.092719] WARNING: CPU: 14 PID: 4775 at drivers/gpu/drm/xe/xe_ttm_vram_mgr.c:298 ttm_vram_mgr_fini+0xf8/0x130 [xe] " v2: use xe_uc_fw_is_running() instead of xe_guc_ct_enabled(). As CT may go down and come back during VF migration. (cherry picked from commit 9b42321a02c50a12b2beb6ae9469606257fbecea)

How severe is CVE-2025-40166?

CVE-2025-40166 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 0.18% probability of exploitation in the next 30 days.

How do I fix CVE-2025-40166?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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