iommupt: Check for missing PAGE_SIZE in the pgsize_bitmap (CVE-2026-64151) | HOL Guard CVE

High · CVSS 8.4CVE-2026-64151

iommupt: Check for missing PAGE_SIZE in the pgsize_bitmap

Answer in brief

CVE-2026-64151 records a High severity (CVSS 8.4) vulnerability in iommupt: Check for missing PAGE_SIZE in the pgsize_bitmap. 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 Jul 19, 2026Updated Aug 17, 2026Source checked Sep 21, 2026First seen by HOL Aug 5, 2026Material review Aug 17, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 8.4
Exploitation: Not marked as known exploited
Affected software: 6 mapped packages or products
Fix availability: Available

Why this deserves its current priority

CVSS is 8.4. 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.

Affected products and reported versions
Product	Affected versions	Fixed versions
cpe:2.3:o:linux:linux_kernel::::::::	Not reported	Not reported
cpe:2.3:o:linux:linux_kernel:7.1:rc1::::::	Not reported	Not reported
cpe:2.3:o:linux:linux_kernel:7.1:rc2::::::	Not reported	Not reported
cpe:2.3:o:linux:linux_kernel:7.1:rc3::::::	Not reported	Not reported

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Linux/Linuxgeneric	>=dcd6a011a8d523a114af2360a8753de5bd60c139 <00850f41da24423587abd6124a790dd4f12bcef3 \|\| >=dcd6a011a8d523a114af2360a8753de5bd60c139 <8ef3f77c440005c7f04229a75976bfc078364247	00850f41da24423587abd6124a790dd4f12bcef3, 8ef3f77c440005c7f04229a75976bfc078364247
Linux/Linuxgeneric	6.19	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to 00850f41da24423587abd6124a790dd4f12bcef3 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Jul 19, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Aug 17, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 5, 2026

Sources and claim methodology

Upstream source description

In the Linux kernel, the following vulnerability has been resolved: iommupt: Check for missing PAGE_SIZE in the pgsize_bitmap Sashiko pointed out that the driver could drop PAGE_SIZE from the pgsize_bitmap. That is technically allowed but nothing does it, and such an iommu_domain would not be used with the DMA API today. Still, it is against the design and it is trivial to fix up. Lift the PT_WARN_ON to the if branch and just skip the fast path.

Quoted source text, attributed separately from HOL analysis.