---
id: CVE-2026-90073
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  net/sched: hhf: clamp quantum before hhf_change() to avoid overflow

  hhf_init() sets q->quantum = psched_mtu(qdisc_dev(sch)) with no overflow
  check
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  net/sched: hhf: clamp quantum before hhf_change() to avoid overflow

  hhf_init() sets q->quantum = psched_mtu(qdisc_dev(sch)) with no overflow
  check. A device with a hug…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 10239edf86f137ce4c39b62ea9575e8053c549a0 <
    2e0f0729f922c8de13801004e2131b57646c7c5f
  - >-
    Linux >= 10239edf86f137ce4c39b62ea9575e8053c549a0 <
    0c66223e90ddb4fd3700965a9241f2fde7bd6bc7
  - >-
    Linux >= 10239edf86f137ce4c39b62ea9575e8053c549a0 <
    20b65bf7ca06e48ec1d62ed8012f71205328dbe4
  - >-
    Linux >= 10239edf86f137ce4c39b62ea9575e8053c549a0 <
    dea2789a9d5ff38bdd77f2e64d550430899e2839
  - >-
    Linux >= 10239edf86f137ce4c39b62ea9575e8053c549a0 <
    fa9c2055f0a60f801ccf286af53d387dc6202c3f
  - >-
    Linux >= 10239edf86f137ce4c39b62ea9575e8053c549a0 <
    99770b5d8e0e1c69b996f74a19d71afd2c4a9aa4
  - >-
    Linux >= 10239edf86f137ce4c39b62ea9575e8053c549a0 <
    2446644b0f6d045b01db6acbaf55552dbec8a59a
  - >-
    Linux >= 10239edf86f137ce4c39b62ea9575e8053c549a0 <
    2164b512b97bb053e8ce4d6e95576f11bed6a005
  - Linux 3.14
published: '2026-09-17'
updated: '2026-09-17'
sourceUpdated: '2026-09-17T17:16:56.387'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-90073'
references:
  - url: 'https://git.kernel.org/stable/c/0c66223e90ddb4fd3700965a9241f2fde7bd6bc7'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/20b65bf7ca06e48ec1d62ed8012f71205328dbe4'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/2164b512b97bb053e8ce4d6e95576f11bed6a005'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/2446644b0f6d045b01db6acbaf55552dbec8a59a'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/2e0f0729f922c8de13801004e2131b57646c7c5f'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/99770b5d8e0e1c69b996f74a19d71afd2c4a9aa4'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/dea2789a9d5ff38bdd77f2e64d550430899e2839'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/fa9c2055f0a60f801ccf286af53d387dc6202c3f'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
  - cve.org
ingestedAt: '2026-09-17T16:21:47.897Z'
epss: 0.00211
epssPercentile: 0.10105
---

## Overview

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

net/sched: hhf: clamp quantum before hhf_change() to avoid overflow

hhf_init() sets q->quantum = psched_mtu(qdisc_dev(sch)) with no overflow
check. A device with a huge MTU (e.g. dummy with max_mtu == 0 accepting
MTU 2147483634) makes weight * quantum overflow the signed deficit in
hhf_dequeue(), spinning forever.

Clamp q->quantum before hhf_change() so both the opt and !opt paths see
a sane quantum. Without this, bare "tc qdisc add ... hhf" succeeds with
a clamped quantum but "tc qdisc add ... hhf limit 1000" (any option
present) fails with -EINVAL because hhf_change() re-validates the
unclamped default (sch_hhf.c:559). 256 matches fq_codel's floor and is
a sane minimum for a DRR quantum.

Conditions to recreate the bug: a device whose MTU (plus
hard_header_len) wraps psched_mtu() into the sign bit (e.g. a dummy
device with max_mtu == 0 accepting MTU 2147483634). Requires
CAP_NET_ADMIN in a user namespace.

## Remediation

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