---
id: CVE-2025-40170
title: 'net: use dst_dev_rcu() in sk_setup_caps()'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  net: use dst_dev_rcu() in sk_setup_caps()

  Use RCU to protect accesses to dst->dev from sk_setup_caps()
  and sk_dst_gso_max_size().

  Also use dst_dev_rcu() in ip6_dst_mt…
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'
cvssSource: cna
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 4a6ce2b6f2ecabbddcfe47e7cf61dd0f00b10e36 <
    13b0e14bfa7e6d506d8d6426b9e6d7feef01ded3
  - >-
    Linux >= 4a6ce2b6f2ecabbddcfe47e7cf61dd0f00b10e36 <
    9f22b5f7f1a32f8bbcc82bf34e34ea63523fcd02
  - >-
    Linux >= 4a6ce2b6f2ecabbddcfe47e7cf61dd0f00b10e36 <
    5d1be493d1110c9e720b4c51a6e587bb2fb4ac12
  - >-
    Linux >= 4a6ce2b6f2ecabbddcfe47e7cf61dd0f00b10e36 <
    a805729c0091073d8f0415cfa96c7acd1bc17a48
  - >-
    Linux >= 4a6ce2b6f2ecabbddcfe47e7cf61dd0f00b10e36 <
    99a2ace61b211b0be861b07fbaa062fca4b58879
  - Linux 4.13
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-06-16T19:33:10.426175Z'
published: '2025-11-12'
updated: '2026-10-30'
sourceUpdated: '2026-10-30T12:22:55.694Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2025-40170'
references:
  - url: 'https://git.kernel.org/stable/c/13b0e14bfa7e6d506d8d6426b9e6d7feef01ded3'
  - url: 'https://git.kernel.org/stable/c/9f22b5f7f1a32f8bbcc82bf34e34ea63523fcd02'
  - url: 'https://git.kernel.org/stable/c/5d1be493d1110c9e720b4c51a6e587bb2fb4ac12'
  - url: 'https://git.kernel.org/stable/c/a805729c0091073d8f0415cfa96c7acd1bc17a48'
  - url: 'https://git.kernel.org/stable/c/99a2ace61b211b0be861b07fbaa062fca4b58879'
tags:
  - cve.org
epss: 0.00193
epssPercentile: 0.09107
ingestedAt: '2026-10-21T12:48:53.682Z'
---

## Overview

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

net: use dst_dev_rcu() in sk_setup_caps()

Use RCU to protect accesses to dst->dev from sk_setup_caps()
and sk_dst_gso_max_size().

Also use dst_dev_rcu() in ip6_dst_mtu_maybe_forward(),
and ip_dst_mtu_maybe_forward().

ip4_dst_hoplimit() can use dst_dev_net_rcu().

## Affected

- `Linux >= 4a6ce2b6f2ecabbddcfe47e7cf61dd0f00b10e36 < 13b0e14bfa7e6d506d8d6426b9e6d7feef01ded3`
- `Linux >= 4a6ce2b6f2ecabbddcfe47e7cf61dd0f00b10e36 < 9f22b5f7f1a32f8bbcc82bf34e34ea63523fcd02`
- `Linux >= 4a6ce2b6f2ecabbddcfe47e7cf61dd0f00b10e36 < 5d1be493d1110c9e720b4c51a6e587bb2fb4ac12`
- `Linux >= 4a6ce2b6f2ecabbddcfe47e7cf61dd0f00b10e36 < a805729c0091073d8f0415cfa96c7acd1bc17a48`
- `Linux >= 4a6ce2b6f2ecabbddcfe47e7cf61dd0f00b10e36 < 99a2ace61b211b0be861b07fbaa062fca4b58879`
- `Linux 4.13`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.