System corruption via incomplete F2FS swap mapping
Published Mar 4, 2026 · Updated Mar 4, 2026
Data corruption in affected Linux Kernel releases allows local users to reboot or hang systems through fragmented F2FS swapfiles. In fs/f2fs/data.c, check_swap_activate treats an unaligned first extent under 2 MB as the last extent and omits later mappings, so swap writes target other files' blocks. Exploitation requires an F2FS swapfile smaller than one section with multiple physical extents, and the resulting corruption can trigger dm-verity reboots or F2FS boot hangs.
Summary
What happened
Data corruption in affected Linux Kernel releases allows local users to reboot or hang systems through fragmented F2FS swapfiles. In fs/f2fs/data.c, check_swap_activate treats an unaligned first extent under 2 MB as the last extent and omits later mappings, so swap writes target other files' blocks. Exploitation requires an F2FS swapfile smaller than one section with multiple physical extents, and the resulting corruption can trigger dm-verity reboots or F2FS boot hangs.
The record
- CVE
- CVE-2026-23233
- Published
- Mar 4, 2026
- Updated
- Mar 4, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- CWE-787, T1499.004
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Mar 4, 2026CVE publishedPublication date reported by the CVE source.
- Mar 4, 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=40d76c393cca83938b11eb7ca8983aa3cd0ed69b <d4534a7f6c92baaf7e12a45fc6e37332cafafc33
- Affected versionversion=6.9
- Affected versionversion=9703d69d9d153bb230711d0d577454552aeb13d4 <1ff415eef513bf12deb058fc50d57788c46c48e6
- Affected versionversion=9703d69d9d153bb230711d0d577454552aeb13d4 <5c145c03188bc9ba1c29e0bc4d527a5978fc47f9
- Affected versionversion=9703d69d9d153bb230711d0d577454552aeb13d4 <607cb9d83838d2cd9f0406c2403ed61aadf0edff
- Affected versionversion=9703d69d9d153bb230711d0d577454552aeb13d4 <fee27b69dde1a05908b350eea42937af2387c4fe
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.
Public exploit references
- stress-ng F2FS swap stress reproducerproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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