---
id: CVE-2026-89567
title: >-
  kernel: jbd2: bound shrinker scans by examined checkpoint buffers
  (CVE-2026-89567)
summary: >-
  A flaw was found in the Linux kernel's jbd2 shrinker. This component, which
  manages journal buffers, does not correctly account for busy checkpoint
  buffers. This oversight can cause the shrinker to hold a critical system lock
  for an extend…
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'
cvssSource: vendor
cwe: CWE-835
vendor: Red Hat
product: Red Hat Enterprise Linux 9
affected:
  - enterprise_linux 10
  - enterprise_linux 6
  - enterprise_linux 9
  - openshift_container_platform 4
published: '2026-09-11'
updated: '2026-09-15'
sourceUpdated: '2026-09-15T16:11:35+00:00'
source: CSAF
sourceUrl: 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89567.json'
references:
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89567.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-89567'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532120'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-89567'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89567'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89567.mbox
  - url: 'https://git.kernel.org/stable/c/edf5fcd0469b7467bd5b37a79502c8d9c3257dbb'
  - url: 'https://git.kernel.org/stable/c/71c6b872c746465fa4b5def239cb296173ca8216'
  - url: 'https://git.kernel.org/stable/c/c2c0fb364685b8996c357d3b050394959b29d6e0'
  - url: 'https://git.kernel.org/stable/c/15cb16496446b94e67f7abcb049b8e2c75cd3d02'
tags:
  - csaf
  - vex
  - red-hat
  - cve.org
epss: 0.00209
epssPercentile: 0.09905
ingestedAt: '2026-09-14T11:11:19.886Z'
---

## Overview

A flaw was found in the Linux kernel's jbd2 shrinker. This component, which manages journal buffers, does not correctly account for busy checkpoint buffers. This oversight can cause the shrinker to hold a critical system lock for an extended period when processing many busy buffers. The prolonged lock contention can lead to system unresponsiveness, such as soft lockups or RCU stalls, ultimately resulting in a Denial of Service (DoS).

## Vendor advisories

- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-09-15 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89567.json)

**kernel: jbd2: bound shrinker scans by examined checkpoint buffers** — rated Moderate by Red Hat. Released 2026-09-11, updated 2026-09-15.

Affected:

- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4

No fix planned:

- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4

Not affected:

- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat OpenShift Container Platform 4

## Remediation

Out of support scope