Kernel memory disclosure and corruption via F2FS sysfs
Published Mar 4, 2026 · Updated Mar 4, 2026
Out-of-bounds access in Linux Kernel F2FS from 3.12 allows local users to disclose kernel memory or interrupt service through sysfs. __sbi_store() and f2fs_sbi_show() treat every attribute value as an unsigned int rather than using the backing field's actual size, causing short fields to be accessed out of bounds and 64-bit values to be truncated. A low-privilege local account must reach sysfs entries for a mounted F2FS filesystem; reads expose adjacent memory, while writes corrupt kernel memory.
Summary
What happened
Out-of-bounds access in Linux Kernel F2FS from 3.12 allows local users to disclose kernel memory or interrupt service through sysfs. __sbi_store() and f2fs_sbi_show() treat every attribute value as an unsigned int rather than using the backing field's actual size, causing short fields to be accessed out of bounds and 64-bit values to be truncated. A low-privilege local account must reach sysfs entries for a mounted F2FS filesystem; reads expose adjacent memory, while writes corrupt kernel memory.
The record
- CVE
- CVE-2026-23235
- Published
- Mar 4, 2026
- Updated
- Mar 4, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- CWE-125
- 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?
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- Affected versionversion=3.12
- Affected versionversion=b59d0bae6ca30c496f298881616258f9cde0d9c6 <3a905e183c047577b154f08a78ac3039e9454703
- Affected versionversion=b59d0bae6ca30c496f298881616258f9cde0d9c6 <438a405fbad6882df0e34b3e1a16839a71f04240
- Affected versionversion=b59d0bae6ca30c496f298881616258f9cde0d9c6 <4ef30b9f1641c9e877792df6b049f1cf507d002d
- Affected versionversion=b59d0bae6ca30c496f298881616258f9cde0d9c6 <6a6c07a9b49e43f0df42d7118fc76aa555c73d98
- Affected versionversion=b59d0bae6ca30c496f298881616258f9cde0d9c6 <98ea0039dbfdd00e5cc1b9a8afa40434476c0955
- Affected versionversion=b59d0bae6ca30c496f298881616258f9cde0d9c6 <d4a594dd952df123cbdcdee9b9640d9d55e4a954
- Affected versionversion=b59d0bae6ca30c496f298881616258f9cde0d9c6 <e85a99db9ab85dfc30d93b0ca0e9156f3127f55a
- Affected versionversion=b59d0bae6ca30c496f298881616258f9cde0d9c6 <eebd72cff518ac87e660aefb8a41224bd88c32ce
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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