# CVE-2026-89922: KVM: s390: Take srcu when importing watchpoint data

> A race condition in Linux KVM s390 watchpoint handling can lead to a use-after-free, causing a denial of service.

- **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:** 16 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-101468, BELL-CVE-2026-89922, DEBIAN-CVE-2026-89922, GHSA-x4qh-jwqp-j7jf, UBUNTU-CVE-2026-89922

## What is CVE-2026-89922?

CVE-2026-89922 is a high-severity vulnerability in Linux, published on 16 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:

KVM: s390: Take srcu when importing watchpoint data

__import_wp_info() backs up the original guest memory contents of a
watchpoint with read_guest_abs(), which is kvm_read_guest() and therefore
resolves the memslot via __kvm_memslots(). That requires kvm->srcu (or
kvm->slots_lock) to be held, otherwise a concurrent memslot update can
free the memslots array under us once its SRCU grace period has elapsed.

As this is not fast path, following lock ordering (mutex first, then
srcu) take the big hammer and hold the srcu for the full import.

## Which versions are affected by CVE-2026-89922?


## How do I fix CVE-2026-89922?

Apply the vendor's patch.

## Is CVE-2026-89922 being exploited?

There is no known exploitation of CVE-2026-89922 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-89922 and fix it if it is affected.

What it is: CVE-2026-89922 is a high-severity vulnerability in Linux, published on 16 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-2026-89922 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-2026-89922/ (Markdown: https://insights.sbomify.com/CVE-2026-89922/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-89922
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-89922
- OSV: https://osv.dev/vulnerability/CVE-2026-89922

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-89922/
Summaries are generated and may contain mistakes; the official description above is the record.