# CVE-2026-68271: drm/nouveau: fix reversed error cleanup order in ucopy functions

> A local attacker can trigger a kernel oops via a null pointer dereference in the nouveau driver's ucopy functions, causing a denial of service.

- **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-2026-68271, DEBIAN-CVE-2026-68271, GHSA-hvp2-xg6j-p7j9, UBUNTU-CVE-2026-68271

## What is CVE-2026-68271?

CVE-2026-68271 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/nouveau: fix reversed error cleanup order in ucopy functions

nouveau_uvmm_vm_bind_ucopy() and nouveau_exec_ucopy() place their error
cleanup labels in allocation order rather than reverse allocation order.
On a u_memcpya() failure for in_sync.s, the goto to err_free_ops (or
err_free_pushs) frees the first allocation and then falls through to
err_free_ins, which calls u_free() on args->in_sync.s.

Since args->in_sync.s still holds the ERR_PTR returned by the failed
u_memcpya(), and ERR_PTR values are not caught by ZERO_OR_NULL_PTR(),
kvfree() proceeds to dereference it, which can result in a kernel oops.
A failure for out_sync.s instead jumps to err_free_ins and skips freeing
the first allocation, leading to a memory leak.

Fix by swapping the cleanup label order so resources are freed in the
correct reverse allocation sequence.

## Which versions are affected by CVE-2026-68271?


## How do I fix CVE-2026-68271?

Apply the vendor's patch.

## Is CVE-2026-68271 being exploited?

There is no known exploitation of CVE-2026-68271 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-68271 and fix it if it is affected.

What it is: CVE-2026-68271 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-2026-68271 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-2026-68271/ (Markdown: https://insights.sbomify.com/CVE-2026-68271/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-68271
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-68271
- OSV: https://osv.dev/vulnerability/CVE-2026-68271

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-68271/
Summaries are generated and may contain mistakes; the official description above is the record.