---
id: CVE-2025-37798
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  codel: remove sch->q.qlen check before qdisc_tree_reduce_backlog()

  After making all ->qlen_notify() callbacks idempotent, now it is safe to
  remove the check of qlen!=0…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  codel: remove sch->q.qlen check before qdisc_tree_reduce_backlog()

  After making all ->qlen_notify() callbacks idempotent, now it is safe to
  remove the check of qlen!=0…
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'
vendor: linux
product: linux_kernel
affected:
  - 'linux_kernel >= 3.5, < 5.4.297'
  - 'linux_kernel >= 5.5, < 5.10.241'
  - 'linux_kernel >= 5.11, < 5.15.190'
  - 'linux_kernel >= 5.16, < 6.1.135'
  - 'linux_kernel >= 6.2, < 6.6.88'
  - 'linux_kernel >= 6.7, < 6.12.24'
  - 'linux_kernel >= 6.13, < 6.13.12'
  - 'linux_kernel >= 6.14, < 6.14.3'
  - linux_kernel = 6.15
  - debian_linux = 11.0
patched:
  - linux_kernel 6.14.3
published: '2025-05-02'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T22:18:18.057'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-37798'
references:
  - url: 'https://git.kernel.org/stable/c/2f9761a94bae33d26e6a81b31b36e7d776d93dc1'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/342debc12183b51773b3345ba267e9263bdfaaef'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/4d55144b12e742404bb3f8fee6038bafbf45619d'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/7a742a9506849d1c1aa71e36c89855ceddc7d58e'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/829c49b6b2ff45b043739168fd1245e4e1a91a30'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/a57fe60ef4cf96bfbb6b58397ec28bdb5a5c6b31'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/cc71a757da78dd4aa1b4a9b19cb011833730ccf2'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/e73c838c80dccb9e4f19becc11d9f3cb4a27d483'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/eda741fe155ddf5ecd2dd3bfbd4fc3c0c7dbb450'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://lists.debian.org/debian-lts-announce/2025/05/msg00045.html'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html'
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
  - cve.org
epss: 0.00228
epssPercentile: 0.13731
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-15T21:45:14.746981Z'
ingestedAt: '2026-10-15T22:48:25.478Z'
---

## Overview

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

codel: remove sch->q.qlen check before qdisc_tree_reduce_backlog()

After making all ->qlen_notify() callbacks idempotent, now it is safe to
remove the check of qlen!=0 from both fq_codel_dequeue() and
codel_qdisc_dequeue().

## Affected

- `linux_kernel >= 3.5, < 5.4.297`
- `linux_kernel >= 5.5, < 5.10.241`
- `linux_kernel >= 5.11, < 5.15.190`
- `linux_kernel >= 5.16, < 6.1.135`
- `linux_kernel >= 6.2, < 6.6.88`
- `linux_kernel >= 6.7, < 6.12.24`
- `linux_kernel >= 6.13, < 6.13.12`
- `linux_kernel >= 6.14, < 6.14.3`
- `linux_kernel = 6.15`
- `debian_linux = 11.0`

## Remediation

Upgrade past the affected range:

- `linux_kernel 6.14.3`