---
id: CVE-2025-68186
title: >-
  In the Linux kernel, the following vulnerability has been resolved:


  ring-buffer: Do not warn in ring_buffer_map_get_reader() when reader catches
  up


  The function ring_buffer_map_get_reader() is a bit more strict than the

  other get reade…
summary: >-
  In the Linux kernel, the following vulnerability has been resolved:


  ring-buffer: Do not warn in ring_buffer_map_get_reader() when reader catches
  up


  The function ring_buffer_map_get_reader() is a bit more strict than the

  other get reade…
severity: none
published: '2025-12-16'
updated: '2026-10-14'
sourceUpdated: '2026-10-14T13:10:00.187'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-68186'
references:
  - url: 'https://git.kernel.org/stable/c/6f5c4f8109fa4d0955b3712597a26b310bdc736f'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/aa997d2d2a0b2e76f4df0f1f12829f02acb4fb6b'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/b42dbef4f208326271434d5ab71c4129a3ddd1a9'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
epss: 0.00197
epssPercentile: 0.08768
ingestedAt: '2026-10-14T13:30:58.448Z'
---

## Overview

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

ring-buffer: Do not warn in ring_buffer_map_get_reader() when reader catches up

The function ring_buffer_map_get_reader() is a bit more strict than the
other get reader functions, and except for certain situations the
rb_get_reader_page() should not return NULL. If it does, it triggers a
warning.

This warning was triggering but after looking at why, it was because
another acceptable situation was happening and it wasn't checked for.

If the reader catches up to the writer and there's still data to be read
on the reader page, then the rb_get_reader_page() will return NULL as
there's no new page to get.

In this situation, the reader page should not be updated and no warning
should trigger.

## Remediation

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