CVE-2026-89499

Received Received - Intake

Ring Buffer Remote Reader Update Failure in Linux Kernel

Publication date: 2026-09-11

Last updated on: 2026-09-13

Assigner: kernel.org

Description

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.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published

2026-09-11

Last Modified

2026-09-13

Generated

2026-10-02

AI Q&A

2026-09-12

EPSS Evaluated

2026-09-29

NVD

CVE-2026-89499

EUVD

EUVD-2026-76405

Affected Vendors & Products

Vendor	Product	Version / Range
linux	linux_kernel	*

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-UNKNOWN

Attack-Flow Graph

Executive Summary

This vulnerability in the Linux kernel involves a flaw in the ring-buffer mechanism where a remote reader update fails when a page swap cannot be completed. Specifically, if the writer moves the head of the buffer before the remote reader catches it, the swap_reader_page callback may return an error. The system currently logs this failure but incorrectly proceeds with the old reader ID, causing issues in the page list arrangement.

Detection Guidance

This vulnerability is specific to the Linux kernel's ring-buffer implementation and may not have direct network detection methods. Monitor kernel logs for pr_warn_ratelimited messages related to ring-buffer failures. Check for event storms or high contention scenarios in kernel logs.

Impact Analysis

This vulnerability could lead to data corruption or loss in the ring buffer, potentially affecting logging and event tracking in the Linux kernel. Under high contention or event storms, it may cause instability or crashes in systems relying on the ring buffer for critical operations.

Compliance Impact

This vulnerability does not directly impact compliance with GDPR, HIPAA, or similar standards. It is a low-level kernel issue affecting ring-buffer operations during event storms, which does not involve data breaches, unauthorized access, or privacy violations typically addressed by these regulations.

Mitigation Strategies

Apply the latest Linux kernel patches that address this issue. Monitor system performance under high event loads. Review kernel logs for ring-buffer related warnings or errors. Consider adjusting buffer sizes if event storms are frequent.

Hi! I’m here to help you understand CVE-2026-89499. Ask me anything about the vulnerability, its impact, or mitigation strategies.

0/70