f2fs: only redirty pinned folios in redirty_blocks (CVE-2026-89841) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-89841

f2fs: only redirty pinned folios in redirty_blocks

Answer in brief

CVE-2026-89841 records a Unknown severity vulnerability in f2fs: only redirty pinned folios in redirty_blocks. 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 16, 2026Updated Sep 16, 2026Source checked Sep 16, 2026First seen by HOL Sep 16, 2026Material review Sep 16, 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	>=5951fee46befbf6176c86482432f4f76e522f16c <445e4a1e6025ecd5312e9a95c1b234192c976ca1 \|\| >=5951fee46befbf6176c86482432f4f76e522f16c <89c65ec3c18903de763cf567c96ab3ef60e5f3b0 \|\| >=5951fee46befbf6176c86482432f4f76e522f16c <85171332742e741ccd6f401c69b6e0d698119e72	445e4a1e6025ecd5312e9a95c1b234192c976ca1, 89c65ec3c18903de763cf567c96ab3ef60e5f3b0, 85171332742e741ccd6f401c69b6e0d698119e72
Linux/Linuxgeneric	6.16	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to 445e4a1e6025ecd5312e9a95c1b234192c976ca1 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 16, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 16, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 16, 2026

Sources and claim methodology

Upstream source description

In the Linux kernel, the following vulnerability has been resolved: f2fs: only redirty pinned folios in redirty_blocks redirty_blocks() pins folios with read_cache_folio() and then walks the same range again with filemap_lock_folio() to redirty them and drop the references it took. Commit 5951fee46bef ("f2fs: Use a folio in redirty_blocks()") changed the second pass to a do/while loop. If read_cache_folio() fails before anything is pinned, page_idx does not advance but the cleanup loop still runs once. If readahead has already populated the failed folio in page cache, that extra iteration finds it and folio_put_refs(folio, 2) drops one reference too many. Later drop_caches or reclaim can then report "BUG: Bad page state". Only redirty the range that was pinned successfully.

Quoted source text, attributed separately from HOL analysis.