# CVE-2026-89764: rust: devres: fix race between concurrent revokers

> A race condition in the Linux kernel's Rust devres implementation allows use-after-free, potentially enabling code execution or privilege escalation.

- **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:** 11 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-89764, DEBIAN-CVE-2026-89764, GHSA-8vmv-qf47-5pwf, UBUNTU-CVE-2026-89764

## What is CVE-2026-89764?

CVE-2026-89764 is a high-severity vulnerability in Linux, published on 11 Sep 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:

rust: devres: fix race between concurrent revokers

There is a potential race condition when two paths try to revoke a
Devres concurrently.

The driver core's devres_release_all() calls Revocable::revoke() via the
release callback, while Devres::drop() calls revoke_nosync() on another
CPU.

The revoker that does not claim the is_available swap returns
immediately, but the revoker that did may still be executing
drop_in_place() on the inner data. This can cause a use-after-free when
the other revoker's caller proceeds to drop adjacent resources that
drop_in_place() still references (e.g., Devres<DmaMappedSgt> racing with
SGTable freeing the backing sg_table and pages).

Fix this by adding a Completion. The release callback signals the
Completion after revoke() finishes, and Devres::drop() waits for it when
it loses the is_available swap. This ensures the wrapped object is fully
torn down before Devres::drop() returns.

## Which versions are affected by CVE-2026-89764?


## How do I fix CVE-2026-89764?

Apply the vendor's patch.

## Is CVE-2026-89764 being exploited?

There is no known exploitation of CVE-2026-89764 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-89764 and fix it if it is affected.

What it is: CVE-2026-89764 is a high-severity vulnerability in Linux, published on 11 Sep 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-2026-89764 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-2026-89764/ (Markdown: https://insights.sbomify.com/CVE-2026-89764/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-89764
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-89764
- OSV: https://osv.dev/vulnerability/CVE-2026-89764

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-89764/
Summaries are generated and may contain mistakes; the official description above is the record.