ring-buffer: Make cpu_buffer::free_page a buffer_data_read_page (CVE-2026-89500) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-89500

ring-buffer: Make cpu_buffer::free_page a buffer_data_read_page

Answer in brief

CVE-2026-89500 records a Unknown severity vulnerability in ring-buffer: Make cpu_buffer::free_page a buffer_data_read_page. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 11, 2026Updated Sep 11, 2026Source checked Sep 11, 2026First seen by HOL Sep 11, 2026Material review Sep 11, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Linux/Linuxgeneric	>=8e7b58c27b3c567316a51079b375b846f9223bba <a1dabe68fb53730bc0be60c5dbfd3f4c560084e7 \|\| >=8e7b58c27b3c567316a51079b375b846f9223bba <d787d509bdf6c88c85e095247daf7456cb7fb772 \|\| >=8e7b58c27b3c567316a51079b375b846f9223bba <7a1fb95de5404134f8758c1295ce88986bdf117c	a1dabe68fb53730bc0be60c5dbfd3f4c560084e7, d787d509bdf6c88c85e095247daf7456cb7fb772, 7a1fb95de5404134f8758c1295ce88986bdf117c
Linux/Linuxgeneric	6.8	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to a1dabe68fb53730bc0be60c5dbfd3f4c560084e7 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 11, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 11, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 11, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.