---
id: CVE-2025-21900
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  NFSv4: Fix a deadlock when recovering state on a sillyrenamed file

  If the file is sillyrenamed, and slated for delete on close, it is
  possible for a server reboot to t…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  NFSv4: Fix a deadlock when recovering state on a sillyrenamed file

  If the file is sillyrenamed, and slated for delete on close, it is
  possible for a server reboot to t…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-667
  - CWE-667
vendor: linux
product: linux_kernel
affected:
  - 'linux_kernel >= 6.11, < 6.12.18'
  - 'linux_kernel >= 6.13, < 6.13.6'
  - linux_kernel = 6.14
patched:
  - linux_kernel 6.13.6
published: '2025-04-01'
updated: '2026-07-30'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-21900'
references:
  - url: 'https://git.kernel.org/stable/c/4fe4ae6c2e01d028856b73b6328b12b8945df871'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/8f8df955f078e1a023ee55161935000a67651f38'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/f41a60bc43e7abbc636fee78bed0d74c31e738b0'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
epss: 0.00342
epssPercentile: 0.24991
ingestedAt: '2026-07-30T06:53:10.861Z'
---

## Overview

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

NFSv4: Fix a deadlock when recovering state on a sillyrenamed file

If the file is sillyrenamed, and slated for delete on close, it is
possible for a server reboot to triggeer an open reclaim, with can again
race with the application call to close(). When that happens, the call
to put_nfs_open_context() can trigger a synchronous delegreturn call
which deadlocks because it is not marked as privileged.

Instead, ensure that the call to nfs4_inode_return_delegation_on_close()
catches the delegreturn, and schedules it asynchronously.

## Affected

- `linux_kernel >= 6.11, < 6.12.18`
- `linux_kernel >= 6.13, < 6.13.6`
- `linux_kernel = 6.14`

## Remediation

Upgrade past the affected range:

- `linux_kernel 6.13.6`