---
id: CVE-2022-4129
title: A flaw was found in the Linux kernel's Layer 2 Tunneling Protocol (L2TP)
summary: >-
  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
  syst…
severity: medium
cvss: 5.5
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-667
vendor: linux
product: layer_2_tunneling_protocol
affected:
  - layer_2_tunneling_protocol < 6.0
  - fedora = 35
  - fedora = 36
  - fedora = 37
patched:
  - layer_2_tunneling_protocol 6.0
published: '2022-11-28'
updated: '2026-10-14'
sourceUpdated: '2026-10-14T14:17:28.110'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2022-4129'
references:
  - url: 'https://lists.debian.org/debian-lts-announce/2023/05/msg00005.html'
    label: secalert@redhat.com
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/7X5SPXMXXFANDASPCKER2JIQO2F3UHCP/
    label: secalert@redhat.com
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/AM5KFIE6JNZXHBA5A2KYDZAT3MEX2B67/
    label: secalert@redhat.com
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JOKXNIM2R4FQCDRQV67UMAY6EBC72QFG/
    label: secalert@redhat.com
  - url: >-
      https://lore.kernel.org/all/20221114191619.124659-1-jakub%40cloudflare.com/t
    label: secalert@redhat.com
  - url: >-
      https://lore.kernel.org/netdev/20221121085426.21315-1-jakub%40cloudflare.com/t
    label: secalert@redhat.com
  - url: 'https://lists.debian.org/debian-lts-announce/2023/05/msg00005.html'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/7X5SPXMXXFANDASPCKER2JIQO2F3UHCP/
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/AM5KFIE6JNZXHBA5A2KYDZAT3MEX2B67/
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JOKXNIM2R4FQCDRQV67UMAY6EBC72QFG/
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://lore.kernel.org/all/20221114191619.124659-1-jakub%40cloudflare.com/t
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://lore.kernel.org/netdev/20221121085426.21315-1-jakub%40cloudflare.com/t
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-794697.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
tags:
  - nvd
  - cve.org
epss: 0.00176
epssPercentile: 0.07132
ingestedAt: '2026-10-14T15:36:13.926Z'
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2025-04-14T15:37:45.752033Z'
---

## Overview

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.

## Affected

- `layer_2_tunneling_protocol < 6.0`
- `fedora = 35`
- `fedora = 36`
- `fedora = 37`

## Remediation

Upgrade past the affected range:

- `layer_2_tunneling_protocol 6.0`