Kernel disruption via stale VM_PAT fork cleanup
Published Apr 16, 2025 · Updated Sep 8, 2026
Improper VM_PAT cleanup in affected Linux kernel branches allows local users to disrupt kernel operation through a failed fork. When track_pfn_copy() fails, copy_page_range() leaves the destination VMA in the maple tree with VM_PAT set despite having neither a PAT reservation nor copied page tables. Cleanup then makes untrack_pfn() query absent page-table state; reaching this path requires local access to mmap a VM_PFNMAP device mapping and invoke fork or clone.
Summary
What happened
Improper VM_PAT cleanup in affected Linux kernel branches allows local users to disrupt kernel operation through a failed fork. When track_pfn_copy() fails, copy_page_range() leaves the destination VMA in the maple tree with VM_PAT set despite having neither a PAT reservation nor copied page tables. Cleanup then makes untrack_pfn() query absent page-table state; reaching this path requires local access to mmap a VM_PFNMAP device mapping and invoke fork or clone.
The record
- CVE
- CVE-2025-22090
- Published
- Apr 16, 2025
- Updated
- Sep 8, 2026
- Vendor
- Siemens
- Product
- SIPLUS S7-1500 CPU 1518-4 PN/DP MFP
- Classifications
- CWE-20, T1499.004
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Apr 16, 2025CVE publishedPublication date reported by the CVE source.
- Sep 8, 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=V3.1.6 <*
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- PAT fork failure reproducerproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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