CVE-2026-89500

Received Received - Intake

Ring Buffer Resize Memory Leak 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: 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.

CVSS Scores

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Meta Information

Published

2026-09-11

Last Modified

2026-09-13

Generated

2026-10-02

AI Q&A

2026-09-12

EPSS Evaluated

2026-10-01

NVD

CVE-2026-89500

EUVD

EUVD-2026-76406

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 mismatch in memory page handling during ring buffer operations. When a cached reader page is discarded after a concurrent resize, the system uses an incorrect page order value for freeing memory. This can cause kernel crashes or memory leaks because the page was allocated with a different size than what is being used to free it.

Detection Guidance

This vulnerability is specific to the Linux kernel's ring buffer implementation and may not have direct detection commands. Monitor kernel logs for crashes or memory leaks after ring buffer resizing events. Check for kernel oops messages or warnings related to memory allocation failures in the ring buffer subsystem.

Impact Analysis

This vulnerability could lead to system instability, including kernel crashes or unexpected behavior, due to improper memory handling. It may also cause memory leaks, which could degrade system performance over time. Users running affected Linux kernel versions might experience crashes or data corruption.

Compliance Impact

This vulnerability is a kernel-level issue in the Linux ring-buffer that could cause kernel crashes or memory leaks due to incorrect page order handling during concurrent ring buffer resizing. It does not directly relate to data privacy, access controls, or audit logging required by standards like GDPR or HIPAA.

Mitigation Strategies

Apply the latest Linux kernel patches or updates that address this issue. If using a custom kernel, backport the fix that ensures the correct page order is used when freeing pages. Avoid concurrent ring buffer resizing operations until patched.

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