---
id: CVE-2026-89567
title: 'jbd2: bound shrinker scans by examined checkpoint buffers'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  jbd2: bound shrinker scans by examined checkpoint buffers

  The jbd2 shrinker currently accounts only checkpoint buffers that it
  successfully releases against nr_to_scan…
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: Linux
product: Linux
affected:
  - >-
    Linux >= b98dba273a0e47dbfade89c9af73c5b012a4eabb <
    6b5366ba63a58819396045ab146bd37ff9e503c6
  - >-
    Linux >= b98dba273a0e47dbfade89c9af73c5b012a4eabb <
    edf5fcd0469b7467bd5b37a79502c8d9c3257dbb
  - >-
    Linux >= b98dba273a0e47dbfade89c9af73c5b012a4eabb <
    71c6b872c746465fa4b5def239cb296173ca8216
  - >-
    Linux >= b98dba273a0e47dbfade89c9af73c5b012a4eabb <
    c2c0fb364685b8996c357d3b050394959b29d6e0
  - >-
    Linux >= b98dba273a0e47dbfade89c9af73c5b012a4eabb <
    15cb16496446b94e67f7abcb049b8e2c75cd3d02
  - Linux 9c31bb2684f8035beca0275349d19d679b679ffb
  - Linux 5fda50e262e65bd553ff777c4b280afd1495a18b
  - Linux 557fda9ed70ebf8eda2620ba3d746215285a1303
  - Linux >= 5.15.129 < 5.16
  - Linux >= 6.1.50 < 6.2
  - Linux >= 6.4.13 < 6.5
  - Linux 6.5
published: '2026-09-11'
updated: '2026-10-21'
sourceUpdated: '2026-10-21T12:47:54.662Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-89567'
references:
  - url: 'https://git.kernel.org/stable/c/6b5366ba63a58819396045ab146bd37ff9e503c6'
  - 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'
  - 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
tags:
  - cve.org
  - csaf
  - vex
  - red-hat
epss: 0.00206
epssPercentile: 0.10767
ingestedAt: '2026-09-14T11:11:19.886Z'
---

## Overview

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

jbd2: bound shrinker scans by examined checkpoint buffers

The jbd2 shrinker currently accounts only checkpoint buffers that it
successfully releases against nr_to_scan.  Busy buffers therefore do not
consume the scan budget.

If a checkpoint transaction contains mostly busy buffers, the shrinker
can scan its entire checkpoint list while holding journal->j_list_lock.
Large checkpoint lists can result in excessive lock hold times and leave
other CPUs spinning on j_list_lock, causing soft lockups or RCU stalls.

Pass nr_to_scan into journal_shrink_one_cp_list() and decrement it for
every buffer examined, including busy buffers.  Pass NULL from checkpoint
cleanup paths so their existing full-list behavior is preserved.

This restores the scan-budget semantics that existed before
journal_shrink_one_cp_list() was changed to always scan a complete
checkpoint list.

## Affected

- `Linux >= b98dba273a0e47dbfade89c9af73c5b012a4eabb < 6b5366ba63a58819396045ab146bd37ff9e503c6`
- `Linux >= b98dba273a0e47dbfade89c9af73c5b012a4eabb < edf5fcd0469b7467bd5b37a79502c8d9c3257dbb`
- `Linux >= b98dba273a0e47dbfade89c9af73c5b012a4eabb < 71c6b872c746465fa4b5def239cb296173ca8216`
- `Linux >= b98dba273a0e47dbfade89c9af73c5b012a4eabb < c2c0fb364685b8996c357d3b050394959b29d6e0`
- `Linux >= b98dba273a0e47dbfade89c9af73c5b012a4eabb < 15cb16496446b94e67f7abcb049b8e2c75cd3d02`
- `Linux 9c31bb2684f8035beca0275349d19d679b679ffb`
- `Linux 5fda50e262e65bd553ff777c4b280afd1495a18b`
- `Linux 557fda9ed70ebf8eda2620ba3d746215285a1303`
- `Linux >= 5.15.129 < 5.16`
- `Linux >= 6.1.50 < 6.2`
- `Linux >= 6.4.13 < 6.5`
- `Linux 6.5`

## Remediation

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

## 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)