dm array: reject an array block whose value size is not the caller's (CVE-2026-89573) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-89573

dm array: reject an array block whose value size is not the caller's

Answer in brief

CVE-2026-89573 records a Unknown severity vulnerability in dm array: reject an array block whose value size is not the caller's. 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 11, 2026Updated Sep 11, 2026Source checked Sep 11, 2026First seen by HOL Sep 11, 2026Material review Sep 11, 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	>=6513c29f44f2cc970c0e9fecfe5a6526c3e73025 <7bf4b5cb42a4e27f36bcbc6209d82a5da9c0168c \|\| >=6513c29f44f2cc970c0e9fecfe5a6526c3e73025 <ac4a5eb8b002a0742c938fc98b922e243f53573a \|\| >=6513c29f44f2cc970c0e9fecfe5a6526c3e73025 <cb409b38b0232ee4385ef55cddcd6fbdd011a8a2 \|\| >=6513c29f44f2cc970c0e9fecfe5a6526c3e73025 <4538a287bdf5d0f9a379c678e5262b9f5783f547	7bf4b5cb42a4e27f36bcbc6209d82a5da9c0168c, ac4a5eb8b002a0742c938fc98b922e243f53573a, cb409b38b0232ee4385ef55cddcd6fbdd011a8a2, 4538a287bdf5d0f9a379c678e5262b9f5783f547
Linux/Linuxgeneric	3.9	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to 7bf4b5cb42a4e27f36bcbc6209d82a5da9c0168c if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 11, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 11, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 11, 2026

Sources and claim methodology

Upstream source description

In the Linux kernel, the following vulnerability has been resolved: dm array: reject an array block whose value size is not the caller's array_block_check() can only compare the header against itself, so a block with value_size 4 and max_entries 1018 is internally consistent and passes. dm-cache keeps two arrays -- mappings at 8 bytes and hints at 4 -- and the roots for both live in the superblock. Point the mappings root at a hint block and __load_mappings() walks it through an info whose value size is 8, so element_at() strides 8 bytes over 4-byte entries and reaches offset 8160 of a 4096-byte block. get_ablock() and __shadow_ablock() are the two places that hold the block and the caller at once. Reject there when the two value sizes disagree. Arrays only ever read their own blocks, so this fires on crafted metadata only.

Quoted source text, attributed separately from HOL analysis.