---
id: CVE-2025-37932
title: 'sch_htb: make htb_qlen_notify() idempotent'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  sch_htb: make htb_qlen_notify() idempotent

  htb_qlen_notify() always deactivates the HTB class and in fact could
  trigger a warning if it is already deactivated. Therefo…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 959466588aa7f84ccf79ae36a1d89542eaf9aaec <
    e6b45f4de763b00dc1c55e685e2dd1aaf525d3c1
  - >-
    Linux >= 959466588aa7f84ccf79ae36a1d89542eaf9aaec <
    32ae12ce6a9f6bace186ca7335220ff59b6cc3cd
  - >-
    Linux >= 959466588aa7f84ccf79ae36a1d89542eaf9aaec <
    967955c9e57f8eebfccc298037d4aaf3d42bc1c9
  - >-
    Linux >= 959466588aa7f84ccf79ae36a1d89542eaf9aaec <
    73cf6af13153d62f9b76eff422eea79dbc70f15e
  - >-
    Linux >= 959466588aa7f84ccf79ae36a1d89542eaf9aaec <
    bbbf5e0f87078b715e7a665d662a2c0e77f044ae
  - >-
    Linux >= 959466588aa7f84ccf79ae36a1d89542eaf9aaec <
    0a188c0e197383683fd093ab1ea6ce9a5869a6ea
  - >-
    Linux >= 959466588aa7f84ccf79ae36a1d89542eaf9aaec <
    a61f1b5921761fbaf166231418bc1db301e5bf59
  - >-
    Linux >= 959466588aa7f84ccf79ae36a1d89542eaf9aaec <
    5ba8b837b522d7051ef81bacf3d95383ff8edce5
  - Linux 4.14
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-11-05T20:45:17.209279Z'
published: '2025-05-20'
updated: '2026-11-05'
sourceUpdated: '2026-11-05T20:52:08.351Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2025-37932'
references:
  - url: 'https://git.kernel.org/stable/c/e6b45f4de763b00dc1c55e685e2dd1aaf525d3c1'
  - url: 'https://git.kernel.org/stable/c/32ae12ce6a9f6bace186ca7335220ff59b6cc3cd'
  - url: 'https://git.kernel.org/stable/c/967955c9e57f8eebfccc298037d4aaf3d42bc1c9'
  - url: 'https://git.kernel.org/stable/c/73cf6af13153d62f9b76eff422eea79dbc70f15e'
  - url: 'https://git.kernel.org/stable/c/bbbf5e0f87078b715e7a665d662a2c0e77f044ae'
  - url: 'https://git.kernel.org/stable/c/0a188c0e197383683fd093ab1ea6ce9a5869a6ea'
  - url: 'https://git.kernel.org/stable/c/a61f1b5921761fbaf166231418bc1db301e5bf59'
  - url: 'https://git.kernel.org/stable/c/5ba8b837b522d7051ef81bacf3d95383ff8edce5'
tags:
  - cve.org
epss: 0.00238
epssPercentile: 0.1487
ingestedAt: '2026-11-05T22:38:31.894Z'
---

## Overview

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

sch_htb: make htb_qlen_notify() idempotent

htb_qlen_notify() always deactivates the HTB class and in fact could
trigger a warning if it is already deactivated. Therefore, it is not
idempotent and not friendly to its callers, like fq_codel_dequeue().

Let's make it idempotent to ease qdisc_tree_reduce_backlog() callers'
life.

## Affected

- `Linux >= 959466588aa7f84ccf79ae36a1d89542eaf9aaec < e6b45f4de763b00dc1c55e685e2dd1aaf525d3c1`
- `Linux >= 959466588aa7f84ccf79ae36a1d89542eaf9aaec < 32ae12ce6a9f6bace186ca7335220ff59b6cc3cd`
- `Linux >= 959466588aa7f84ccf79ae36a1d89542eaf9aaec < 967955c9e57f8eebfccc298037d4aaf3d42bc1c9`
- `Linux >= 959466588aa7f84ccf79ae36a1d89542eaf9aaec < 73cf6af13153d62f9b76eff422eea79dbc70f15e`
- `Linux >= 959466588aa7f84ccf79ae36a1d89542eaf9aaec < bbbf5e0f87078b715e7a665d662a2c0e77f044ae`
- `Linux >= 959466588aa7f84ccf79ae36a1d89542eaf9aaec < 0a188c0e197383683fd093ab1ea6ce9a5869a6ea`
- `Linux >= 959466588aa7f84ccf79ae36a1d89542eaf9aaec < a61f1b5921761fbaf166231418bc1db301e5bf59`
- `Linux >= 959466588aa7f84ccf79ae36a1d89542eaf9aaec < 5ba8b837b522d7051ef81bacf3d95383ff8edce5`
- `Linux 4.14`

## Remediation

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