ext4: fix transaction overflow during writeback (CVE-2026-100073) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-100073

ext4: fix transaction overflow during writeback

Answer in brief

CVE-2026-100073 records a Unknown severity vulnerability in ext4: fix transaction overflow during writeback. 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 25, 2026Updated Sep 25, 2026Source checked Sep 25, 2026First seen by HOL Sep 25, 2026Material review Sep 25, 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	>=95ad8ee45cdbc321c135a2db895d48b374ef0f87 <a22464c5df5827e884a5a7d3d8fb03870e5bb6c8 \|\| >=95ad8ee45cdbc321c135a2db895d48b374ef0f87 <46e8e31771f4f1c5e1cdec37a889a6730e42e9f1 \|\| 2b6d39229bc783198222cddd31e2fbded93c8db7 \|\| >=6.16.3 <6.17	a22464c5df5827e884a5a7d3d8fb03870e5bb6c8, 46e8e31771f4f1c5e1cdec37a889a6730e42e9f1, 6.17
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 a22464c5df5827e884a5a7d3d8fb03870e5bb6c8 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 25, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 25, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 25, 2026

Sources and claim methodology

Upstream source description

In the Linux kernel, the following vulnerability has been resolved: ext4: fix transaction overflow during writeback Commit 95ad8ee45cdb ("ext4: correct the reserved credits for extent conversion") was correct to note that we need to reserve enough credits for all extents possibly underlying a large folio. However it was too eager to reduce the number of reserved credits. Extent conversion may not only need to touch several leaf extent blocks, it may also need to split extents - for example a single large unwritten extent may need to be split into many small written ones in case of sparse folio dirtying. This can thus result not only in extent leaf modifications but also in a need to allocate new extent tree nodes. As a result the reserved transaction credits were not sufficient in some corner cases. Use ext4_meta_trans_blocks() for correct upper bound credit estimate.

Quoted source text, attributed separately from HOL analysis.