# CVE-2026-74440: drm/xe: Wait on external BO kernel fences in exec IOCTL

> A race condition in the Linux kernel's Xe driver allows concurrent memory access during GPU job scheduling, potentially leading to data corruption or leaks.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **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:** Yes
- **Published:** 15 Aug 2026
- **Updated:** 16 Oct 2026
- **Also known as:** BELL-CVE-2026-74440, DEBIAN-CVE-2026-74440, GHSA-7mhj-6hx6-xpjh, UBUNTU-CVE-2026-74440

## What is CVE-2026-74440?

CVE-2026-74440 is a high-severity vulnerability in Linux, published on 15 Aug 2026. 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: 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)

## Which versions are affected by CVE-2026-74440?


## How do I fix CVE-2026-74440?

Apply the vendor's patch.

## Is CVE-2026-74440 being exploited?

There is no known exploitation of CVE-2026-74440 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-74440 and fix it if it is affected.

What it is: CVE-2026-74440 is a high-severity vulnerability in Linux, published on 15 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-74440 in the wild and no public exploit code.

Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-74440/ (Markdown: https://insights.sbomify.com/CVE-2026-74440/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-74440
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-74440
- OSV: https://osv.dev/vulnerability/CVE-2026-74440

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-74440/
Summaries are generated and may contain mistakes; the official description above is the record.