CVE-2026-89573

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

State: Published
Severity: 7.8 High
Published: Sep 11, 2026
Updated: Oct 19, 2026
Reserved: Sep 11, 2026

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.

Scores

CVSS	Score	Vector	Source
3.1	7.8 High	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H	Linux

Weaknesses

The record names no weakness.

Affected Products

Product	Versions
LinuxLinux	6513c29f44f2cc970c0e9fecfe5a6526c3e73025 to before 35cd3b278448c79614f65ab6bbc9ed348d847df9Affected 6513c29f44f2cc970c0e9fecfe5a6526c3e73025 to before a8237cb8fa0a628d903e76635bfdeae4202036b9Affected 6513c29f44f2cc970c0e9fecfe5a6526c3e73025 to before a530a9a419a7c5fdb7dae55ffa2dd7a130631842Affected 6513c29f44f2cc970c0e9fecfe5a6526c3e73025 to before 522fa26da24ccaa298ebe3c1c97395d2d63dfc21Affected 6513c29f44f2cc970c0e9fecfe5a6526c3e73025 to before 7bf4b5cb42a4e27f36bcbc6209d82a5da9c0168cAffected 6513c29f44f2cc970c0e9fecfe5a6526c3e73025 to before ac4a5eb8b002a0742c938fc98b922e243f53573aAffected 6513c29f44f2cc970c0e9fecfe5a6526c3e73025 to before cb409b38b0232ee4385ef55cddcd6fbdd011a8a2Affected 6513c29f44f2cc970c0e9fecfe5a6526c3e73025 to before 4538a287bdf5d0f9a379c678e5262b9f5783f547Affected
LinuxLinux	3.9Affected before 3.9Not affected 5.10.270 through 5.10.Not affected 5.15.221 through 5.15.Not affected 6.1.188 through 6.1.Not affected 6.6.157 through 6.6.Not affected 6.12.109 through 6.12.Not affected 6.18.50 through 6.18.Not affected 7.2.4 through 7.2.*Not affected 7.3 and laterNot affected

Product

Versions

LinuxLinux

6513c29f44f2cc970c0e9fecfe5a6526c3e73025 to before 35cd3b278448c79614f65ab6bbc9ed348d847df9Affected
6513c29f44f2cc970c0e9fecfe5a6526c3e73025 to before a8237cb8fa0a628d903e76635bfdeae4202036b9Affected
6513c29f44f2cc970c0e9fecfe5a6526c3e73025 to before a530a9a419a7c5fdb7dae55ffa2dd7a130631842Affected
6513c29f44f2cc970c0e9fecfe5a6526c3e73025 to before 522fa26da24ccaa298ebe3c1c97395d2d63dfc21Affected
6513c29f44f2cc970c0e9fecfe5a6526c3e73025 to before 7bf4b5cb42a4e27f36bcbc6209d82a5da9c0168cAffected
6513c29f44f2cc970c0e9fecfe5a6526c3e73025 to before ac4a5eb8b002a0742c938fc98b922e243f53573aAffected
6513c29f44f2cc970c0e9fecfe5a6526c3e73025 to before cb409b38b0232ee4385ef55cddcd6fbdd011a8a2Affected
6513c29f44f2cc970c0e9fecfe5a6526c3e73025 to before 4538a287bdf5d0f9a379c678e5262b9f5783f547Affected

LinuxLinux

3.9Affected
before 3.9Not affected
5.10.270 through 5.10.*Not affected
5.15.221 through 5.15.*Not affected
6.1.188 through 6.1.*Not affected
6.6.157 through 6.6.*Not affected
6.12.109 through 6.12.*Not affected
6.18.50 through 6.18.*Not affected
7.2.4 through 7.2.*Not affected
7.3 and laterNot affected

References

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