---
id: CVE-2026-89500
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  ring-buffer: Make cpu_buffer::free_page a buffer_data_read_page

  Discarding a cached reader page after a concurrent ring buffer resize
  uses the new global subbuf_order …
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  ring-buffer: Make cpu_buffer::free_page a buffer_data_read_page

  Discarding a cached reader page after a concurrent ring buffer resize
  uses the new global subbuf_order …
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'
cwe:
  - CWE-763
  - CWE-401
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 8e7b58c27b3c567316a51079b375b846f9223bba <
    d8f52dc3c3f1f987d8cf920ccd8d66590870bf3f
  - >-
    Linux >= 8e7b58c27b3c567316a51079b375b846f9223bba <
    a1dabe68fb53730bc0be60c5dbfd3f4c560084e7
  - >-
    Linux >= 8e7b58c27b3c567316a51079b375b846f9223bba <
    d787d509bdf6c88c85e095247daf7456cb7fb772
  - >-
    Linux >= 8e7b58c27b3c567316a51079b375b846f9223bba <
    7a1fb95de5404134f8758c1295ce88986bdf117c
  - Linux 6.8
published: '2026-09-11'
updated: '2026-10-03'
sourceUpdated: '2026-10-03T11:17:42.450'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89500'
references:
  - url: 'https://git.kernel.org/stable/c/7a1fb95de5404134f8758c1295ce88986bdf117c'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/a1dabe68fb53730bc0be60c5dbfd3f4c560084e7'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/d787d509bdf6c88c85e095247daf7456cb7fb772'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/d8f52dc3c3f1f987d8cf920ccd8d66590870bf3f'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89500.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-89500'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532513'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-89500'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89500'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89500.mbox
  - url: 'https://kernelcve.org/list/?q=CVE-2026-89500'
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
  - score-dispute
epss: 0.00168
epssPercentile: 0.06064
scores:
  nvd: 7.8
  vendor: 5.5
  cna: 7.8
ingestedAt: '2026-09-14T15:23:07.475Z'
---

## Overview

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

ring-buffer: Make cpu_buffer::free_page a buffer_data_read_page

Discarding a cached reader page after a concurrent ring buffer resize
uses the new global subbuf_order for the free_pages() call. This
mismatched order may crashes the kernel or leaks memory because the cached
page was allocated under the old size.

Save the actual free_page order alongside the page address to ensure we
always refer to the correct value and do not rely on the potentially
stalled cpu_buffer->subbuf_order value. The simplest is to make
free_page a buffer_data_read_page which already covers exactly what we
need: a page address and a page order.

## 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 · no fix planned: Red Hat Enterprise Linux 10 · updated 2026-10-24 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89500.json)