---
id: CVE-2025-39697
title: 'NFS: Fix a race when updating an existing write'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  NFS: Fix a race when updating an existing write

  After nfs_lock_and_join_requests() tests for whether the request is
  still attached to the mapping, nothing prevents a c…
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 >= bd37d6fce184836bd5e7cd90ce40116a4fadaf2a <
    0ff42a32784e0f2cb46a46da8e9f473538c13e1b
  - >-
    Linux >= bd37d6fce184836bd5e7cd90ce40116a4fadaf2a <
    f230d40147cc37eb3aef4d50e2e2c06ea73d9a77
  - >-
    Linux >= bd37d6fce184836bd5e7cd90ce40116a4fadaf2a <
    c32e3c71aaa1c1ba05da88605e2ddd493c58794f
  - >-
    Linux >= bd37d6fce184836bd5e7cd90ce40116a4fadaf2a <
    181feb41f0b268e6288bf9a7b984624d7fe2031d
  - >-
    Linux >= bd37d6fce184836bd5e7cd90ce40116a4fadaf2a <
    92278ae36935a54e65fef9f8ea8efe7e80481ace
  - >-
    Linux >= bd37d6fce184836bd5e7cd90ce40116a4fadaf2a <
    202a3432d21ac060629a760fff3b0a39859da3ea
  - >-
    Linux >= bd37d6fce184836bd5e7cd90ce40116a4fadaf2a <
    76d2e3890fb169168c73f2e4f8375c7cc24a765e
  - Linux 4.14
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-06-10T20:42:24.236193Z'
published: '2025-09-05'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T01:08:03.870Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2025-39697'
references:
  - url: 'https://git.kernel.org/stable/c/0ff42a32784e0f2cb46a46da8e9f473538c13e1b'
  - url: 'https://git.kernel.org/stable/c/f230d40147cc37eb3aef4d50e2e2c06ea73d9a77'
  - url: 'https://git.kernel.org/stable/c/c32e3c71aaa1c1ba05da88605e2ddd493c58794f'
  - url: 'https://git.kernel.org/stable/c/181feb41f0b268e6288bf9a7b984624d7fe2031d'
  - url: 'https://git.kernel.org/stable/c/92278ae36935a54e65fef9f8ea8efe7e80481ace'
  - url: 'https://git.kernel.org/stable/c/202a3432d21ac060629a760fff3b0a39859da3ea'
  - url: 'https://git.kernel.org/stable/c/76d2e3890fb169168c73f2e4f8375c7cc24a765e'
tags:
  - cve.org
epss: 0.00153
epssPercentile: 0.04386
ingestedAt: '2026-10-15T05:52:46.079Z'
---

## Overview

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

NFS: Fix a race when updating an existing write

After nfs_lock_and_join_requests() tests for whether the request is
still attached to the mapping, nothing prevents a call to
nfs_inode_remove_request() from succeeding until we actually lock the
page group.
The reason is that whoever called nfs_inode_remove_request() doesn't
necessarily have a lock on the page group head.

So in order to avoid races, let's take the page group lock earlier in
nfs_lock_and_join_requests(), and hold it across the removal of the
request in nfs_inode_remove_request().

## Affected

- `Linux >= bd37d6fce184836bd5e7cd90ce40116a4fadaf2a < 0ff42a32784e0f2cb46a46da8e9f473538c13e1b`
- `Linux >= bd37d6fce184836bd5e7cd90ce40116a4fadaf2a < f230d40147cc37eb3aef4d50e2e2c06ea73d9a77`
- `Linux >= bd37d6fce184836bd5e7cd90ce40116a4fadaf2a < c32e3c71aaa1c1ba05da88605e2ddd493c58794f`
- `Linux >= bd37d6fce184836bd5e7cd90ce40116a4fadaf2a < 181feb41f0b268e6288bf9a7b984624d7fe2031d`
- `Linux >= bd37d6fce184836bd5e7cd90ce40116a4fadaf2a < 92278ae36935a54e65fef9f8ea8efe7e80481ace`
- `Linux >= bd37d6fce184836bd5e7cd90ce40116a4fadaf2a < 202a3432d21ac060629a760fff3b0a39859da3ea`
- `Linux >= bd37d6fce184836bd5e7cd90ce40116a4fadaf2a < 76d2e3890fb169168c73f2e4f8375c7cc24a765e`
- `Linux 4.14`

## Remediation

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