# CVE-2026-99090: drm/amdgpu: serialize vblank counter reads against GPU reset


- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 26 Oct 2026
- **Updated:** 27 Oct 2026
- **Also known as:** AZL-111125, BELL-CVE-2026-99090, DEBIAN-CVE-2026-99090, GHSA-3hrf-vpmj-gj4m, UBUNTU-CVE-2026-99090

## What is CVE-2026-99090?

CVE-2026-99090 is a vulnerability in Linux, published on 26 Oct 2026. 

### Official description

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

drm/amdgpu: serialize vblank counter reads against GPU reset

The vblank counter callback reads display registers and scanout
position without holding reset_domain->sem. During GPU recovery,
display commit work can call the callback while reset owns the
semaphore for writing. The hardware access then triggers the
lockdep_assert_held() in amdgpu_device_skip_hw_access() and sets
TAINT_WARN when lockdep is enabled.

Try to acquire the reset semaphore for reading before accessing the
hardware, and hold it across the counter and scanout-position reads.
If reset is already in progress, return DRM's cached software vblank
count instead. This avoids blocking behind reset and avoids accessing
display hardware while it is being reset.

The cached count is less accurate than the hardware count, but is
used only when reset prevents a safe hardware read. This addresses
the reset-time warning from this vblank path; it does not suppress or
fix unrelated lockdep warnings.

(cherry picked from commit 51a4359f7431a4be5e42803c8bdaf7e0e5be2934)

## Which versions are affected by CVE-2026-99090?


## How do I fix CVE-2026-99090?

Upgrade to a fixed version.

## Is CVE-2026-99090 being exploited?

There is no known exploitation of CVE-2026-99090 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-99090 and fix it if it is affected.

What it is: CVE-2026-99090 is a vulnerability in Linux, published on 26 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-99090 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-2026-99090/ (Markdown: https://insights.sbomify.com/CVE-2026-99090/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-99090
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-99090
- OSV: https://osv.dev/vulnerability/CVE-2026-99090

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-99090/
Summaries are generated and may contain mistakes; the official description above is the record.