Kernel memory corruption via huge-zero-page PMD move
Published Apr 3, 2026 · Updated Apr 3, 2026
Memory corruption in mm/huge_memory.c in Linux Kernel allows local users to corrupt kernel state through UFFDIO_MOVE of a huge zero page. In move_pages_huge_pmd(), the huge-zero-page branch passes a NULL folio into folio_mk_pmd(), yielding a bogus PFN or NULL dereference, and rebuilds the destination PMD without preserving pmd_special(). The path requires local low-privileged access to invoke UFFDIO_MOVE and produces an invalid physical mapping, a NULL dereference, or huge-page refcount corruption.
Summary
What happened
Memory corruption in mm/huge_memory.c in Linux Kernel allows local users to corrupt kernel state through UFFDIO_MOVE of a huge zero page. In move_pages_huge_pmd(), the huge-zero-page branch passes a NULL folio into folio_mk_pmd(), yielding a bogus PFN or NULL dereference, and rebuilds the destination PMD without preserving pmd_special(). The path requires local low-privileged access to invoke UFFDIO_MOVE and produces an invalid physical mapping, a NULL dereference, or huge-page refcount corruption.
The record
- CVE
- CVE-2026-31397
- Published
- Apr 3, 2026
- Updated
- Apr 3, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Apr 3, 2026CVE publishedPublication date reported by the CVE source.
- Apr 3, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=6.16
- Affected versionversion=e3981db444a0a18d350d9f92e3f2e8d489b54211 <e3133d0986dc5a231d5419167dbac65312b28b41
- Affected versionversion=e3981db444a0a18d350d9f92e3f2e8d489b54211 <f3caaee0f9e489fd2282d4ce45791dc8aed2da62
- Affected versionversion=e3981db444a0a18d350d9f92e3f2e8d489b54211 <fae654083bfa409bb2244f390232e2be47f05bfc
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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