---
id: CVE-2025-21909
title: 'wifi: nl80211: reject cooked mode if it is set along with other flags'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  wifi: nl80211: reject cooked mode if it is set along with other flags

  It is possible to set both MONITOR_FLAG_COOK_FRAMES and MONITOR_FLAG_ACTIVE
  flags simultaneously …
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 66f7ac50ed7cc5c19a62bc97e8f6e7891004a03a <
    5ea856d93794c4afa5542defd8c61f2708dc245a
  - >-
    Linux >= 66f7ac50ed7cc5c19a62bc97e8f6e7891004a03a <
    351eb7ac53ff1cd94d893c0c4534ced2f36ae7d7
  - >-
    Linux >= 66f7ac50ed7cc5c19a62bc97e8f6e7891004a03a <
    cd1bdcb77fdc03c253137e55bae10551b3481461
  - >-
    Linux >= 66f7ac50ed7cc5c19a62bc97e8f6e7891004a03a <
    236f41ca728f23210b31ed2d1d8a6df575a4b2d6
  - >-
    Linux >= 66f7ac50ed7cc5c19a62bc97e8f6e7891004a03a <
    ebebbb0eded2ed9a1abfa31962f6fb699e6abce7
  - >-
    Linux >= 66f7ac50ed7cc5c19a62bc97e8f6e7891004a03a <
    521e55c2b0d6028861ac0a2d06aa57bb0e3ac486
  - >-
    Linux >= 66f7ac50ed7cc5c19a62bc97e8f6e7891004a03a <
    ac4860141300581d3e2f6c6dafa37220f7ea9f65
  - >-
    Linux >= 66f7ac50ed7cc5c19a62bc97e8f6e7891004a03a <
    49f27f29446a5bfe633dd2cc0cfebd48a1a5e77f
  - Linux 2.6.26
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-11-05T20:36:38.030485Z'
published: '2025-04-01'
updated: '2026-11-05'
sourceUpdated: '2026-11-05T20:41:47.419Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2025-21909'
references:
  - url: 'https://git.kernel.org/stable/c/5ea856d93794c4afa5542defd8c61f2708dc245a'
  - url: 'https://git.kernel.org/stable/c/351eb7ac53ff1cd94d893c0c4534ced2f36ae7d7'
  - url: 'https://git.kernel.org/stable/c/cd1bdcb77fdc03c253137e55bae10551b3481461'
  - url: 'https://git.kernel.org/stable/c/236f41ca728f23210b31ed2d1d8a6df575a4b2d6'
  - url: 'https://git.kernel.org/stable/c/ebebbb0eded2ed9a1abfa31962f6fb699e6abce7'
  - url: 'https://git.kernel.org/stable/c/521e55c2b0d6028861ac0a2d06aa57bb0e3ac486'
  - url: 'https://git.kernel.org/stable/c/ac4860141300581d3e2f6c6dafa37220f7ea9f65'
  - url: 'https://git.kernel.org/stable/c/49f27f29446a5bfe633dd2cc0cfebd48a1a5e77f'
tags:
  - cve.org
epss: 0.00178
epssPercentile: 0.07433
ingestedAt: '2026-11-05T22:38:31.853Z'
---

## Overview

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

wifi: nl80211: reject cooked mode if it is set along with other flags

It is possible to set both MONITOR_FLAG_COOK_FRAMES and MONITOR_FLAG_ACTIVE
flags simultaneously on the same monitor interface from the userspace. This
causes a sub-interface to be created with no IEEE80211_SDATA_IN_DRIVER bit
set because the monitor interface is in the cooked state and it takes
precedence over all other states. When the interface is then being deleted
the kernel calls WARN_ONCE() from check_sdata_in_driver() because of missing
that bit.

Fix this by rejecting MONITOR_FLAG_COOK_FRAMES if it is set along with
other flags.

Found by Linux Verification Center (linuxtesting.org) with Syzkaller.

## Affected

- `Linux >= 66f7ac50ed7cc5c19a62bc97e8f6e7891004a03a < 5ea856d93794c4afa5542defd8c61f2708dc245a`
- `Linux >= 66f7ac50ed7cc5c19a62bc97e8f6e7891004a03a < 351eb7ac53ff1cd94d893c0c4534ced2f36ae7d7`
- `Linux >= 66f7ac50ed7cc5c19a62bc97e8f6e7891004a03a < cd1bdcb77fdc03c253137e55bae10551b3481461`
- `Linux >= 66f7ac50ed7cc5c19a62bc97e8f6e7891004a03a < 236f41ca728f23210b31ed2d1d8a6df575a4b2d6`
- `Linux >= 66f7ac50ed7cc5c19a62bc97e8f6e7891004a03a < ebebbb0eded2ed9a1abfa31962f6fb699e6abce7`
- `Linux >= 66f7ac50ed7cc5c19a62bc97e8f6e7891004a03a < 521e55c2b0d6028861ac0a2d06aa57bb0e3ac486`
- `Linux >= 66f7ac50ed7cc5c19a62bc97e8f6e7891004a03a < ac4860141300581d3e2f6c6dafa37220f7ea9f65`
- `Linux >= 66f7ac50ed7cc5c19a62bc97e8f6e7891004a03a < 49f27f29446a5bfe633dd2cc0cfebd48a1a5e77f`
- `Linux 2.6.26`

## Remediation

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