perf: arm_pmuv3: Zero initialize hw_id branch stack field (CVE-2026-90272) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-90272

perf: arm_pmuv3: Zero initialize hw_id branch stack field

Answer in brief

CVE-2026-90272 records a Unknown severity vulnerability in perf: arm_pmuv3: Zero initialize hw_id branch stack field. 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 17, 2026Updated Sep 17, 2026Source checked Sep 17, 2026First seen by HOL Sep 17, 2026Material review Sep 17, 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	>=58074a0fce66c6c97b35ce8a28ed4e7b780f9a8f <57b72442c1672963fd51ab441ca1b71f6dc79b66 \|\| >=58074a0fce66c6c97b35ce8a28ed4e7b780f9a8f <988e11b69ef9d4034e19c64407030fa948580c3d \|\| >=58074a0fce66c6c97b35ce8a28ed4e7b780f9a8f <7c3b63386c27bed8d59a4b4c283d02860420eb0a	57b72442c1672963fd51ab441ca1b71f6dc79b66, 988e11b69ef9d4034e19c64407030fa948580c3d, 7c3b63386c27bed8d59a4b4c283d02860420eb0a
Linux/Linuxgeneric	6.17	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to 57b72442c1672963fd51ab441ca1b71f6dc79b66 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 17, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 17, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 17, 2026

Sources and claim methodology

Upstream source description

In the Linux kernel, the following vulnerability has been resolved: perf: arm_pmuv3: Zero initialize hw_id branch stack field PERF_SAMPLE_BRANCH_HW_INDEX is supported by BRBE so hw_id is passed to userspace, but it's never set by the BRBE driver. Zero initialize it as it should be according to the docs: * For the architectures whose raw branch records are * already stored in age order, the hw_idx should be 0. It's probably too risky to remove PERF_SAMPLE_BRANCH_HW_INDEX from BRBE now in case anyone is setting it and reading the value, but zero initializing the whole struct also protects against the same issue with new fields that are added in the future.

Quoted source text, attributed separately from HOL analysis.