dm array: reject an array block whose value size is not the caller's
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 7 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
- Fix · CNA Linux (Linux) Fixed in 5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.109, 6.18.50, 7.2.4, 7.3
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 7 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 8 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Container Platform 4 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Container Platform 5 | Affected | No fix yet: Fix deferred |
Timeline
- 2026-10-02 Threatist record created from CVE-2026-89573
- 2026-10-03 Alias added: GHSA-pg3h-8qxx-35hj
- 2026-10-18 CISA SSVC decision points changed
- 2026-10-19 Fix available: Linux/[email protected] · CNA
- 2026-11-06 Affected versions changed · Red Hat
References
Other 8
- https://git.kernel.org/stable/c/35cd3b278448c79614f65ab6bbc9ed348d847df9
- https://git.kernel.org/stable/c/a8237cb8fa0a628d903e76635bfdeae4202036b9
- https://git.kernel.org/stable/c/a530a9a419a7c5fdb7dae55ffa2dd7a130631842
- https://git.kernel.org/stable/c/522fa26da24ccaa298ebe3c1c97395d2d63dfc21
- https://git.kernel.org/stable/c/7bf4b5cb42a4e27f36bcbc6209d82a5da9c0168c
- https://git.kernel.org/stable/c/ac4a5eb8b002a0742c938fc98b922e243f53573a
- https://git.kernel.org/stable/c/cb409b38b0232ee4385ef55cddcd6fbdd011a8a2
- https://git.kernel.org/stable/c/4538a287bdf5d0f9a379c678e5262b9f5783f547
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Sources
- CVE-2026-89573 · CVE Program
- CVE-2026-89573 · NVD
- FIRST EPSS
- GHSA-pg3h-8qxx-35hj · GitHub Advisory Database · CC BY 4.0
- CVE-2026-89573 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences