Time-of-check Time-of-use (TOCTOU) Affecting kernel-debug-devel-matched package, versions *


Severity

Recommended
medium

Based on Red Hat Enterprise Linux security rating.

Threat Intelligence

EPSS
0.13% (3rd percentile)

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  • Snyk IDSNYK-RHEL10-KERNELDEBUGDEVELMATCHED-18880887
  • published18 Aug 2026
  • disclosed15 Aug 2026

Introduced: 15 Aug 2026

NewCVE-2026-74440  (opens in a new tab)
CWE-367  (opens in a new tab)

How to fix?

There is no fixed version for RHEL:10 kernel-debug-devel-matched.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-debug-devel-matched package and not the kernel-debug-devel-matched package as distributed by RHEL. See How to fix? for RHEL:10 relevant fixed versions and status.

In the Linux kernel, the following vulnerability has been resolved:

drm/xe: Wait on external BO kernel fences in exec IOCTL

Before arming a user job, xe_exec_ioctl() only added the VM's dma-resv KERNEL slot as a dependency. That slot covers rebinds and the kernel operations of the VM's private BOs, but not external BOs (bo->vm == NULL), which carry their kernel operations (evictions, moves, ...) in their own dma-resv KERNEL slot.

The DMA_RESV_USAGE_KERNEL slot is the cross-driver contract for memory management operations that must complete before the BO or its backing store may be used: any accessor is required to wait on the KERNEL fences before touching the resv. By skipping the external BOs' KERNEL slots, the exec path violated that contract and could schedule a user job while a kernel operation on an external BO mapped by the VM was still in flight, racing against it and potentially reading or writing memory that was being moved.

Replace the VM-only dependency with an iteration over every object locked by the exec, adding each object's KERNEL slot as a job dependency. This covers the VM resv (rebinds and private BOs) as well as every external BO, mirroring the drm_gpuvm_resv_add_fence() call that later publishes the job fence to the same set of objects. Long-running mode continues to skip this, as before.

(cherry picked from commit a6b842acf3ddd1efc53a56de9260cfa718fb35e7)

CVSS Base Scores

version 3.1