f2fs: validate MOVE_RANGE destination size

Answer in brief

CVE-2026-89840 records a Unknown severity vulnerability in f2fs: validate MOVE_RANGE destination size. 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	>=4dd6f977fc778e5a0da604e5f8cb2f36d163d27b <dcae1eeda53149f219dd6af93b3083b7271c1c63 \|\| >=4dd6f977fc778e5a0da604e5f8cb2f36d163d27b <e533889fc26aea0cd83c90327063f272061dd820	dcae1eeda53149f219dd6af93b3083b7271c1c63, e533889fc26aea0cd83c90327063f272061dd820
Linux/Linuxgeneric	4.8	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to dcae1eeda53149f219dd6af93b3083b7271c1c63 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: validate MOVE_RANGE destination size F2FS_IOC_MOVE_RANGE checks the source range, but not the destination end before updating i_size. A source hole can expose this: __clone_blkaddrs() skips NULL_ADDR entries and returns success, so the caller can still extend the destination inode with unchecked pos_out + len. Reject destination overflow and use inode_newsize_ok() before extending the destination inode.

Quoted source text, attributed separately from HOL analysis.