Linux Kernel 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)

The Linux kernel is affected, specifically the Intel Xe DRM/GuC GPU driver (drivers/gpu/drm/xe). No single fixed kernel version is given as a release tag; the fix is delivered via stable-tree commits 2c6e5904c5bd, 9f64b3cd051b, and fa708415566b (backports of upstream commit 9b42321a02c5). Distribution-level coverage is available: Ubuntu addresses it in USN-8126-1 (https://ubuntu.com/security/notices/USN-8126-1) and USN-8125-1 (https://ubuntu.com/security/notices/USN-8125-1). NVD did not provide structured CPE data, so exact affected version ranges should be derived from the specific kernel branch each stable commit was applied to and from the Ubuntu advisories.