Kernel disruption via omitted per-CPU migration marker
Published Sep 11, 2026 · Updated Sep 11, 2026
Incorrect code generation in Linux 7.2 on s390 allows attackers to disrupt kernel execution during interrupted per-CPU operations. MVIY_PERCPU stringifies existing string literals, and GNU as before 2.39 merges its quoted macro arguments, so GEN_MVIY silently omits the mviy instruction. Exposure requires an s390 kernel built with the older assembler; after CPU migration, the exception return path cannot repair the per-CPU address register.
Summary
What happened
Incorrect code generation in Linux 7.2 on s390 allows attackers to disrupt kernel execution during interrupted per-CPU operations. MVIY_PERCPU stringifies existing string literals, and GNU as before 2.39 merges its quoted macro arguments, so GEN_MVIY silently omits the mviy instruction. Exposure requires an s390 kernel built with the older assembler; after CPU migration, the exception return path cannot repair the per-CPU address register.
The record
- CVE
- CVE-2026-89459
- Published
- Sep 11, 2026
- Updated
- Sep 11, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- Unavailable
- Attack vector
- Unavailable
- Privileges
- Unavailable
Timeline
How it unfolded
- Sep 11, 2026CVE publishedPublication date reported by the CVE source.
- Sep 11, 2026Record updatedLatest update available in the CVE record.
Exploitability
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=7.2
- Affected versionversion=a737737cdb9c94e40a9926cdc2320f874c05d709 <101782f8945a125044347312d74d488c05741c4a
- Affected versionversion=a737737cdb9c94e40a9926cdc2320f874c05d709 <91770b08a120967077ae78600612f18bc5ee3caf
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
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Technologies
Your stack
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