# CVE-2026-80606: drm/xe/userptr: Hold notifier_lock for write on inject test path

> A race condition in the Linux kernel Xe driver causes a kernel warning and potential denial of service when a specific test injection configuration is enabled.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/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:** 28 Aug 2026
- **Updated:** 16 Oct 2026
- **Also known as:** BELL-CVE-2026-80606, DEBIAN-CVE-2026-80606, GHSA-hgrf-3223-9cqm, UBUNTU-CVE-2026-80606

## What is CVE-2026-80606?

CVE-2026-80606 is a high-severity vulnerability in Linux, published on 28 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/userptr: Hold notifier_lock for write on inject test path

When CONFIG_DRM_XE_USERPTR_INVAL_INJECT=y, xe_pt_svm_userptr_pre_commit()
runs vma_check_userptr() with the svm notifier_lock taken for read. The
test injection causes vma_check_userptr() to call
xe_vma_userptr_force_invalidate(), which feeds into
xe_vma_userptr_do_inval() with drm_gpusvm_ctx.in_notifier=true. That
flag tells drm_gpusvm_unmap_pages() the caller already holds
notifier_lock for write and only asserts the mode. Because the caller
actually holds it for read, the assertion fires:

  WARNING: drivers/gpu/drm/drm_gpusvm.c:1669 at \
           drm_gpusvm_unmap_pages+0xd4/0x130 [drm_gpusvm_helper]
  Call Trace:
   xe_vma_userptr_do_inval+0x40d/0xfd0 [xe]
   xe_vma_userptr_invalidate_pass1+0x3e6/0x8d0 [xe]
   xe_vma_userptr_force_invalidate+0xde/0x290 [xe]
   vma_check_userptr.constprop.0+0x1c6/0x220 [xe]
   xe_pt_svm_userptr_pre_commit+0x6a3/0xc60 [xe]
   ...
   xe_vm_bind_ioctl+0x3a0a/0x4480 [xe]

Acquire notifier_lock for write in pre-commit when the inject Kconfig
is enabled, via new helpers xe_pt_svm_userptr_notifier_lock()/_unlock().
Rename xe_svm_assert_held_read() to
xe_svm_assert_held_read_or_inject_write() so it asserts the correct
mode under each build configuration. Production builds
(CONFIG_DRM_XE_USERPTR_INVAL_INJECT=n) keep the existing read-mode
behavior bit-for-bit.

(cherry picked from commit 80ccbd97ffee8ad2e73167d826fe7be548364365)

## Which versions are affected by CVE-2026-80606?


## How do I fix CVE-2026-80606?

Apply the vendor's patch.

## Is CVE-2026-80606 being exploited?

There is no known exploitation of CVE-2026-80606 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-80606 and fix it if it is affected.

What it is: CVE-2026-80606 is a high-severity vulnerability in Linux, published on 28 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-2026-80606 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-2026-80606/ (Markdown: https://insights.sbomify.com/CVE-2026-80606/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-80606
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-80606
- OSV: https://osv.dev/vulnerability/CVE-2026-80606

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-80606/
Summaries are generated and may contain mistakes; the official description above is the record.