---
id: CVE-2025-21791
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  vrf: use RCU protection in l3mdev_l3_out()

  l3mdev_l3_out() can be called without RCU being held:

  raw_sendmsg()
   ip_push_pending_frames()
    ip_send_skb()
     ip_local_o…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  vrf: use RCU protection in l3mdev_l3_out()

  l3mdev_l3_out() can be called without RCU being held:

  raw_sendmsg()
   ip_push_pending_frames()
    ip_send_skb()
     ip_local_o…
severity: high
cvss: 7.8
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-416
vendor: linux
product: linux_kernel
affected:
  - 'linux_kernel >= 4.9, < 6.1.129'
  - 'linux_kernel >= 6.2, < 6.6.79'
  - 'linux_kernel >= 6.7, < 6.12.16'
  - 'linux_kernel >= 6.13, < 6.13.4'
  - linux_kernel = 6.14
patched:
  - linux_kernel 6.13.4
published: '2025-02-27'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T02:17:35.843'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-21791'
references:
  - url: 'https://git.kernel.org/stable/c/022cac1c693add610ae76ede03adf4d9d5a2cf21'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/20a3489b396764cc9376e32a9172bee26a89dc3b'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/5bb4228c32261d06e4fbece37ec3828bcc005b6b'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/6ccaa5797f5362a2aad6baa6ddaf4715ac2dd51e'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/6d0ce46a93135d96b7fa075a94a88fe0da8e8773'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/7b81425b517accefd46bee854d94954f5c57e019'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/c40cb5c03e37552d6eff963187109e2c3f78ef6f'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/c7574740be8ce68a57d0aece24987b9be2114c3c'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://lists.debian.org/debian-lts-announce/2025/03/msg00028.html'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-784472.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
tags:
  - nvd
  - cve.org
epss: 0.00268
epssPercentile: 0.18896
ingestedAt: '2026-10-15T03:30:12.797Z'
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2025-02-27T17:57:16.236835Z'
---

## Overview

In the Linux kernel, the following vulnerability has been resolved:

vrf: use RCU protection in l3mdev_l3_out()

l3mdev_l3_out() can be called without RCU being held:

raw_sendmsg()
 ip_push_pending_frames()
  ip_send_skb()
   ip_local_out()
    __ip_local_out()
     l3mdev_ip_out()

Add rcu_read_lock() / rcu_read_unlock() pair to avoid
a potential UAF.

## Affected

- `linux_kernel >= 4.9, < 6.1.129`
- `linux_kernel >= 6.2, < 6.6.79`
- `linux_kernel >= 6.7, < 6.12.16`
- `linux_kernel >= 6.13, < 6.13.4`
- `linux_kernel = 6.14`

## Remediation

Upgrade past the affected range:

- `linux_kernel 6.13.4`