---
id: CVE-2026-89503
title: >-
  kernel: ring-buffer: Fix subbuf resize race with ring_buffer_alloc_read_page()
  (CVE-2026-89503)
summary: >-
  A flaw was found in the Linux kernel's ring-buffer component. A race condition
  exists in the `ring_buffer_alloc_read_page()` function when it interacts with
  `ring_buffer_subbuf_order_set`. This can lead to an incorrect memory
  allocation wh…
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-367
vendor: Red Hat
product: Red Hat Enterprise Linux 10
affected:
  - enterprise_linux 10
published: '2026-09-11'
updated: '2026-09-14'
sourceUpdated: '2026-09-14T08:20:09+00:00'
source: CSAF
sourceUrl: 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89503.json'
references:
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89503.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-89503'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532017'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-89503'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89503'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89503.mbox
  - url: 'https://git.kernel.org/stable/c/2dc510957fe8fd098ab3c3147ebdf34d00cd2734'
  - url: 'https://git.kernel.org/stable/c/53106e9262a310ef2c9a9321168c03705940c678'
  - url: 'https://git.kernel.org/stable/c/e743527c5bfdceda1095bc0a9e596e2aebb6a9c3'
tags:
  - csaf
  - vex
  - red-hat
  - cve.org
  - score-dispute
epss: 0.00161
epssPercentile: 0.05761
scores:
  vendor: 5.5
  cna: 7.8
ingestedAt: '2026-09-14T15:23:07.475Z'
---

## Overview

A flaw was found in the Linux kernel's ring-buffer component. A race condition exists in the `ring_buffer_alloc_read_page()` function when it interacts with `ring_buffer_subbuf_order_set`. This can lead to an incorrect memory allocation where the buffer page's order (`bpage->order`) does not match the actual allocated memory. This mismatch could potentially cause system instability or a denial of service.

## Vendor advisories

- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10 · no fix planned: Red Hat Enterprise Linux 10 · updated 2026-09-14 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89503.json)

**kernel: ring-buffer: Fix subbuf resize race with ring_buffer_alloc_read_page()** — rated Moderate by Red Hat. Released 2026-09-11, updated 2026-09-14.

Affected:

- Red Hat Enterprise Linux 10

No fix planned:

- Red Hat Enterprise Linux 10

Not affected:

- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4

## Remediation

Fix deferred