---
id: CVE-2025-21638
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  sctp: sysctl: auth_enable: avoid using current->nsproxy

  As mentioned in a previous commit of this series, using the 'net'
  structure via 'current' is not recommended fo…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  sctp: sysctl: auth_enable: avoid using current->nsproxy

  As mentioned in a previous commit of this series, using the 'net'
  structure via 'current' is not recommended fo…
severity: high
cvss: 7.1
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H'
cwe:
  - CWE-476
vendor: linux
product: linux_kernel
affected:
  - 'linux_kernel >= 3.10.41, < 3.11'
  - 'linux_kernel >= 3.12.20, < 3.13'
  - 'linux_kernel >= 3.14.5, < 5.4.290'
  - 'linux_kernel >= 5.5, < 5.10.234'
  - 'linux_kernel >= 5.11, < 5.15.177'
  - 'linux_kernel >= 5.16, < 6.1.125'
  - 'linux_kernel >= 6.2, < 6.6.72'
  - 'linux_kernel >= 6.7, < 6.12.10'
  - linux_kernel = 6.13
patched:
  - linux_kernel 6.12.10
published: '2025-01-19'
updated: '2026-07-30'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-21638'
references:
  - url: 'https://git.kernel.org/stable/c/15649fd5415eda664ef35780c2013adeb5d9c695'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/1b67030d39f2b00f94ac1f0af11ba6657589e4d3'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/7ec30c54f339c640aa7e49d7e9f7bbed6bd42bf6'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/bd2a2939423566c654545fa3e96a656662a0af9e'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/c184bc621e3cef03ac9ba81a50dda2dae6a21d36'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/cf387cdebfaebae228dfba162f94c567a67610c3'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/dc583e7e5f8515ca489c0df28e4362a70eade382'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://lists.debian.org/debian-lts-announce/2025/03/msg00001.html'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://lists.debian.org/debian-lts-announce/2025/03/msg00002.html'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-265688.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
tags:
  - nvd
epss: 0.00237
epssPercentile: 0.13098
ingestedAt: '2026-07-30T06:53:08.852Z'
---

## Overview

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

sctp: sysctl: auth_enable: avoid using current->nsproxy

As mentioned in a previous commit of this series, using the 'net'
structure via 'current' is not recommended for different reasons:

- Inconsistency: getting info from the reader's/writer's netns vs only
  from the opener's netns.

- current->nsproxy can be NULL in some cases, resulting in an 'Oops'
  (null-ptr-deref), e.g. when the current task is exiting, as spotted by
  syzbot [1] using acct(2).

The 'net' structure can be obtained from the table->data using
container_of().

Note that table->data could also be used directly, but that would
increase the size of this fix, while 'sctp.ctl_sock' still needs to be
retrieved from 'net' structure.

## Affected

- `linux_kernel >= 3.10.41, < 3.11`
- `linux_kernel >= 3.12.20, < 3.13`
- `linux_kernel >= 3.14.5, < 5.4.290`
- `linux_kernel >= 5.5, < 5.10.234`
- `linux_kernel >= 5.11, < 5.15.177`
- `linux_kernel >= 5.16, < 6.1.125`
- `linux_kernel >= 6.2, < 6.6.72`
- `linux_kernel >= 6.7, < 6.12.10`
- `linux_kernel = 6.13`

## Remediation

Upgrade past the affected range:

- `linux_kernel 6.12.10`