ring-buffer: Fix subbuf resize race with ring_buffer_alloc_read_page() (CVE-2026-89503) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-89503

ring-buffer: Fix subbuf resize race with ring_buffer_alloc_read_page()

Answer in brief

CVE-2026-89503 records a Unknown severity vulnerability in ring-buffer: Fix subbuf resize race with ring_buffer_alloc_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	>=bce761d757452ba5eb77e11fecc37a04b67494e7 <2dc510957fe8fd098ab3c3147ebdf34d00cd2734 \|\| >=bce761d757452ba5eb77e11fecc37a04b67494e7 <53106e9262a310ef2c9a9321168c03705940c678 \|\| >=bce761d757452ba5eb77e11fecc37a04b67494e7 <e743527c5bfdceda1095bc0a9e596e2aebb6a9c3	2dc510957fe8fd098ab3c3147ebdf34d00cd2734, 53106e9262a310ef2c9a9321168c03705940c678, e743527c5bfdceda1095bc0a9e596e2aebb6a9c3
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 2dc510957fe8fd098ab3c3147ebdf34d00cd2734 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: Fix subbuf resize race with ring_buffer_alloc_read_page() ring_buffer_alloc_read_page() is racy with ring_buffer_subbuf_order_set, it can allocate a reader page with an outdated order. This isn't a big issue, the user can still re-allocate a new reader page and try again. However, what is more problematic is if the value of subbuf_order changes in the middle of ring_buffer_alloc_read_page(). In that case, bpage->order might not match the actual allocated memory. Use bpage->order for the allocation to prevent this race.

Quoted source text, attributed separately from HOL analysis.