---
id: CVE-2026-98010
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  net/sched: drr: clamp quantum in change class

  drr_change_class() rejects explicit quantum==0 but falls back to
  psched_mtu() with no floor
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  net/sched: drr: clamp quantum in change class

  drr_change_class() rejects explicit quantum==0 but falls back to
  psched_mtu() with no floor. With a crafted size table qd…
severity: medium
cvss: 5.5
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-835
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 13d2a1d2b032de08d7dcab6a1edcd47802681f96 <
    e2297bbf9cf6ece86f1d1f8c683517a994990f9e
  - >-
    Linux >= 13d2a1d2b032de08d7dcab6a1edcd47802681f96 <
    560794ee6e040b6e1c4ac2b3c8909f341a4596ee
  - >-
    Linux >= 13d2a1d2b032de08d7dcab6a1edcd47802681f96 <
    23fea7e6736b2e1c6f6f2f05cccf33d36834da73
  - >-
    Linux >= 13d2a1d2b032de08d7dcab6a1edcd47802681f96 <
    b464affe9f9dfe41ac48930c376e3fb8596651b0
  - >-
    Linux >= 13d2a1d2b032de08d7dcab6a1edcd47802681f96 <
    dc8b374214ef5bba4882bbd95b361e42555cfc0d
  - >-
    Linux >= 13d2a1d2b032de08d7dcab6a1edcd47802681f96 <
    d43cded350fe1218493ad3d37a276aff14108ae6
  - >-
    Linux >= 13d2a1d2b032de08d7dcab6a1edcd47802681f96 <
    8f756ae1c87414ce9cc21b30e6e4c036d6e9e80b
  - >-
    Linux >= 13d2a1d2b032de08d7dcab6a1edcd47802681f96 <
    8382abec0f1568d0a5590d75a3df92f23fcf5196
  - Linux 2.6.29
published: '2026-09-25'
updated: '2026-10-03'
sourceUpdated: '2026-10-03T11:18:24.017'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-98010'
references:
  - url: 'https://git.kernel.org/stable/c/23fea7e6736b2e1c6f6f2f05cccf33d36834da73'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/560794ee6e040b6e1c4ac2b3c8909f341a4596ee'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/8382abec0f1568d0a5590d75a3df92f23fcf5196'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/8f756ae1c87414ce9cc21b30e6e4c036d6e9e80b'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/b464affe9f9dfe41ac48930c376e3fb8596651b0'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/d43cded350fe1218493ad3d37a276aff14108ae6'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/dc8b374214ef5bba4882bbd95b361e42555cfc0d'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/e2297bbf9cf6ece86f1d1f8c683517a994990f9e'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98010.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-98010'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2541141'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-98010'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-98010'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98010.mbox
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
epss: 0.00177
epssPercentile: 0.07163
cvssSource: vendor
ingestedAt: '2026-09-25T11:06:38.859Z'
---

## Overview

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

net/sched: drr: clamp quantum in change class

drr_change_class() rejects explicit quantum==0 but falls back to
psched_mtu() with no floor. With a crafted size table qdisc_pkt_len
reaches ~2 GiB, so quantum=1 (or a zero psched_mtu on a headerless
device) makes the deficit-refill loop spin under the qdisc lock.

Add clamp_t(u32, quantum, 256, 1<<20) after the zero reject and on the
fallback path. The explicit-zero reject is preserved.

Conditions to recreate the bug:
  CONFIG_NET_SCH_DRR=y. Requires CAP_NET_ADMIN (namespace-local via
  unshare -Urn suffices).

  tc qdisc add dev dummy0 root drr
  tc class add dev dummy0 parent 1: classid 1:1 drr quantum 1

## Remediation

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

## Vendor advisories

- **Red Hat VEX** · Low · affected: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat OpenShift Container Platform 4 · updated 2026-10-17 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98010.json)