btrfs: qgroup: fix a wrong length calculation in qgroup_free_reserved_data() (CVE-2026-90259) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-90259

btrfs: qgroup: fix a wrong length calculation in qgroup_free_reserved_data()

Answer in brief

CVE-2026-90259 records a Unknown severity vulnerability in btrfs: qgroup: fix a wrong length calculation in qgroup_free_reserved_data(). 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	>=bc42bda22345efdb5d8b578d1b4df2c6eaa85c58 <e6edde29990af8064b9d12217ec03db231ccd55d \|\| >=bc42bda22345efdb5d8b578d1b4df2c6eaa85c58 <c4c136555ff90f1e2921cc42da43daac0ef9985e \|\| >=bc42bda22345efdb5d8b578d1b4df2c6eaa85c58 <9102b179512e11644fb0489ae62010a09afa199c	e6edde29990af8064b9d12217ec03db231ccd55d, c4c136555ff90f1e2921cc42da43daac0ef9985e, 9102b179512e11644fb0489ae62010a09afa199c
Linux/Linuxgeneric	4.13	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to e6edde29990af8064b9d12217ec03db231ccd55d 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: btrfs: qgroup: fix a wrong length calculation in qgroup_free_reserved_data() In that function, we round down the start position and round up the ending position. But during the calculation of @len, we use "round_up(start + len, sectorsize)", which is the rounded up end position, not the rounded up length. Which results a much larger length, and later we are still using "start + len", which is completely incorrect. Fix it by declaring a local @aligned_start and @aligned_len and use them instead.

Quoted source text, attributed separately from HOL analysis.