CVE-2025-40166 drm/xe/guc: Check GuC running state before deregistering exec queue
A missing state check in the Linux kernel's Xe GPU driver causes a null dereference and kernel warning when unbinding a running exec queue.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-40166?
CVE-2025-40166 is a high-severity vulnerability in Linux, published on 12 Nov 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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)
Which versions are affected by CVE-2025-40166?
How do I fix CVE-2025-40166?
Apply the vendor's patch.
Is CVE-2025-40166 being exploited?
There is no known exploitation of CVE-2025-40166 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2025-40166, DEBIAN-CVE-2025-40166, GHSA-v9hw-4wx3-7mqf, ROOT-OS-DEBIAN-13-CVE-2025-40166, ROOT-OS-UBUNTU-2404-CVE-2025-40166, UBUNTU-CVE-2025-40166.