---
id: CVE-2025-40080
title: 'nbd: restrict sockets to TCP and UDP'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  nbd: restrict sockets to TCP and UDP

  Recently, syzbot started to abuse NBD with all kinds of sockets.

  Commit cf1b2326b734 ("nbd: verify socket is supported during set…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= cf1b2326b734896734c6e167e41766f9cee7686a <
    c365e8f20f4201d873a70385bd919f0fb531e960
  - >-
    Linux >= cf1b2326b734896734c6e167e41766f9cee7686a <
    4f9e6ff6319dbcebea64b50af0304cf0ad7e97e7
  - >-
    Linux >= cf1b2326b734896734c6e167e41766f9cee7686a <
    37ad11f20e164c23ce827dd455b42c0fdd29685c
  - >-
    Linux >= cf1b2326b734896734c6e167e41766f9cee7686a <
    808e2335bc1cf2293b9e36ccc94c267c81509c71
  - >-
    Linux >= cf1b2326b734896734c6e167e41766f9cee7686a <
    9f7c02e031570e8291a63162c6c046dc15ff85b0
  - Linux 4df728651b8a99693c69962d8e5a5b9e5a3bbcc7
  - Linux 083322455c67d278c56a66b73f1221f004ee600a
  - Linux 4fa1cbd587ef967812f9d9f6ce46ec1dead7502c
  - Linux >= 4.14.152 < 4.15
  - Linux >= 4.19.82 < 4.20
  - Linux >= 5.3.9 < 5.4
  - Linux 5.4
published: '2025-10-28'
updated: '2026-09-08'
sourceUpdated: '2026-09-08T08:42:47.980Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2025-40080'
references:
  - url: 'https://git.kernel.org/stable/c/c365e8f20f4201d873a70385bd919f0fb531e960'
  - url: 'https://git.kernel.org/stable/c/4f9e6ff6319dbcebea64b50af0304cf0ad7e97e7'
  - url: 'https://git.kernel.org/stable/c/37ad11f20e164c23ce827dd455b42c0fdd29685c'
  - url: 'https://git.kernel.org/stable/c/808e2335bc1cf2293b9e36ccc94c267c81509c71'
  - url: 'https://git.kernel.org/stable/c/9f7c02e031570e8291a63162c6c046dc15ff85b0'
tags:
  - cve.org
epss: 0.00193
epssPercentile: 0.07878
ingestedAt: '2026-09-08T15:33:26.996Z'
---

## Overview

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

nbd: restrict sockets to TCP and UDP

Recently, syzbot started to abuse NBD with all kinds of sockets.

Commit cf1b2326b734 ("nbd: verify socket is supported during setup")
made sure the socket supported a shutdown() method.

Explicitely accept TCP and UNIX stream sockets.

## Affected

- `Linux >= cf1b2326b734896734c6e167e41766f9cee7686a < c365e8f20f4201d873a70385bd919f0fb531e960`
- `Linux >= cf1b2326b734896734c6e167e41766f9cee7686a < 4f9e6ff6319dbcebea64b50af0304cf0ad7e97e7`
- `Linux >= cf1b2326b734896734c6e167e41766f9cee7686a < 37ad11f20e164c23ce827dd455b42c0fdd29685c`
- `Linux >= cf1b2326b734896734c6e167e41766f9cee7686a < 808e2335bc1cf2293b9e36ccc94c267c81509c71`
- `Linux >= cf1b2326b734896734c6e167e41766f9cee7686a < 9f7c02e031570e8291a63162c6c046dc15ff85b0`
- `Linux 4df728651b8a99693c69962d8e5a5b9e5a3bbcc7`
- `Linux 083322455c67d278c56a66b73f1221f004ee600a`
- `Linux 4fa1cbd587ef967812f9d9f6ce46ec1dead7502c`
- `Linux >= 4.14.152 < 4.15`
- `Linux >= 4.19.82 < 4.20`
- `Linux >= 5.3.9 < 5.4`
- `Linux 5.4`

## Remediation

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