---
id: CVE-2026-89499
title: 'ring-buffer: Stop remote reader update when page swap fails'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  ring-buffer: Stop remote reader update when page swap fails

  The remote swap_reader_page callback can return -EBUSY when the writer
  moves the head before the remote cat…
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'
cvssSource: cna
cwe:
  - CWE-390
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 2e67fabd8b77c4f482df9b211bca1b495c6c2c24 <
    a14a97048e48471e283d76879b83d2ae323e0722
  - >-
    Linux >= 2e67fabd8b77c4f482df9b211bca1b495c6c2c24 <
    5eab74874d11160725c42ab676ba97a797a362eb
  - Linux 7.1
published: '2026-09-11'
updated: '2026-10-19'
sourceUpdated: '2026-10-19T08:47:50.883Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-89499'
references:
  - url: 'https://git.kernel.org/stable/c/a14a97048e48471e283d76879b83d2ae323e0722'
  - url: 'https://git.kernel.org/stable/c/5eab74874d11160725c42ab676ba97a797a362eb'
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89499.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-89499'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532499'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-89499'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89499'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89499.mbox
tags:
  - cve.org
  - csaf
  - vex
  - red-hat
  - score-dispute
epss: 0.00165
epssPercentile: 0.05672
scores:
  cna: 7.8
  vendor: 5.5
ingestedAt: '2026-09-14T15:23:07.475Z'
---

## Overview

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

ring-buffer: Stop remote reader update when page swap fails

The remote swap_reader_page callback can return -EBUSY when the writer
moves the head before the remote catches it, particularly during an event
storm on a small buffer. __rb_get_reader_page_from_remote() currently
warns about that failure but continues with the unchanged reader ID and
rearranges the local page list as though the swap succeeded.

Handle the callback failure as a recoverable error. Report it with
pr_warn_ratelimited() and return NULL. Callers already handle a NULL reader
page as a failed attempt. This avoids splicing the same page as both the
previous and new reader without flooding the log under contention.

## Affected

- `Linux >= 2e67fabd8b77c4f482df9b211bca1b495c6c2c24 < a14a97048e48471e283d76879b83d2ae323e0722`
- `Linux >= 2e67fabd8b77c4f482df9b211bca1b495c6c2c24 < 5eab74874d11160725c42ab676ba97a797a362eb`
- `Linux 7.1`

## Remediation

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

## Vendor advisories

- **Red Hat VEX** · Moderate · updated 2026-09-15 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89499.json)