# CVE-2022-4129: Race condition in Linux kernel (l2tp)

> A local attacker can trigger a race condition in the Linux kernel L2TP module to cause a NULL pointer dereference and system crash.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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:** 28 Nov 2022
- **Updated:** 14 Oct 2026
- **Also known as:** DEBIAN-CVE-2022-4129, GHSA-6hvc-j4m8-jp74, OESA-2022-2141, OESA-2022-2142, UBUNTU-CVE-2022-4129

## What is CVE-2022-4129?

CVE-2022-4129 is a medium-severity vulnerability in Fedoraproject Fedora, published on 28 Nov 2022. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A flaw was found in the Linux kernel's Layer 2 Tunneling Protocol (L2TP). A missing lock when clearing sk_user_data can lead to a race condition and NULL pointer dereference. A local user could use this flaw to potentially crash the system causing a denial of service.

Weakness: CWE-667 (Improper Locking)

## Which versions are affected by CVE-2022-4129?

It affects 2 products.


Products: Fedoraproject Fedora, Linux Layer 2 Tunneling Protocol.

## How do I fix CVE-2022-4129?

Apply the vendor's patch.

## Is CVE-2022-4129 being exploited?

There is no known exploitation of CVE-2022-4129 in the wild and no public exploit code.

## Other vulnerabilities in Fedoraproject Fedora

- [CVE-2024-4577](https://insights.sbomify.com/CVE-2024-4577/): PHP-CGI OS Command Injection (critical 9.8, exploited in the wild)
- [CVE-2021-39226](https://insights.sbomify.com/CVE-2021-39226/): Grafana Authentication Bypass (critical 9.8, exploited in the wild)
- [CVE-2019-5544](https://insights.sbomify.com/CVE-2019-5544/): VMware ESXi and Horizon DaaS OpenSLP Heap-Based Buffer Overflow (critical 9.8, exploited in the wild)
- [CVE-2024-4947](https://insights.sbomify.com/CVE-2024-4947/): Google Chromium V8 Type Confusion (critical 9.6, exploited in the wild)
- [CVE-2024-4671](https://insights.sbomify.com/CVE-2024-4671/): Google Chromium Visuals Use-After-Free (critical 9.6, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2022-4129 and fix it if it is affected.

What it is: CVE-2022-4129 is a medium-severity vulnerability in Fedoraproject Fedora, published on 28 Nov 2022. 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-2022-4129 in the wild and no public exploit code.

Affected product: Fedoraproject Fedora. 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-2022-4129/ (Markdown: https://insights.sbomify.com/CVE-2022-4129/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-4129
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-4129
- OSV: https://osv.dev/vulnerability/CVE-2022-4129

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-4129/
Summaries are generated and may contain mistakes; the official description above is the record.