# CVE-2026-68272: drm/amdgpu: validate CP_GFX_SHADOW chunk size in CS pass1

> An unprivileged local user can cause a kernel crash by submitting a zero-length CP_GFX_SHADOW chunk to the AMDGPU driver.

- **Severity:** Not scored
- **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:** 10 Aug 2026
- **Updated:** 17 Aug 2026
- **Also known as:** BELL-CVE-2026-68272, DEBIAN-CVE-2026-68272, GHSA-c7h3-6rq5-x6h3, UBUNTU-CVE-2026-68272

## What is CVE-2026-68272?

CVE-2026-68272 is a vulnerability in Linux, published on 10 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/amdgpu: validate CP_GFX_SHADOW chunk size in CS pass1

Add a minimum-length check for the AMDGPU_CHUNK_ID_CP_GFX_SHADOW chunk in
amdgpu_cs_pass1(), matching the gate already present for the IB, FENCE and
BO_HANDLES chunk types.

The CP_GFX_SHADOW case previously shared a bare break with the dependency
and syncobj chunk types, which do not dereference a fixed-size struct. When
userspace submits this chunk with length_dw == 0, vmemdup_array_user() is
called with size 0 and returns ZERO_SIZE_PTR, which passes the IS_ERR()
check. amdgpu_cs_p2_shadow() then dereferences chunk->kdata as a struct
drm_amdgpu_cs_chunk_cp_gfx_shadow (reading shadow->flags), faulting on the
ZERO_SIZE_PTR and causing a NULL-pointer dereference.

This is reachable by an unprivileged process in the render group. Reject
undersized chunks with -EINVAL during pass1 so the bad submission is
rejected before pass2 ever dereferences the data.

(cherry picked from commit 7f61b2eef7415eccdb40850aca0de94211948657)

## Which versions are affected by CVE-2026-68272?


## How do I fix CVE-2026-68272?

Apply the vendor's patch.

## Is CVE-2026-68272 being exploited?

There is no known exploitation of CVE-2026-68272 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-68272 and fix it if it is affected.

What it is: CVE-2026-68272 is a vulnerability in Linux, published on 10 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-2026-68272 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-2026-68272/ (Markdown: https://insights.sbomify.com/CVE-2026-68272/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-68272
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-68272
- OSV: https://osv.dev/vulnerability/CVE-2026-68272

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-68272/
Summaries are generated and may contain mistakes; the official description above is the record.