Kernel memory corruption via unvalidated JFS metadata
Published Jul 4, 2025 · Updated Aug 5, 2026
Out-of-bounds access in Linux JFS allows attackers to corrupt kernel memory and crash the system via a crafted filesystem image. dbMount accepts unvalidated db_agheight, db_agwidth, and db_agstart metadata, allowing dbAllocAG to perform a negative shift and index beyond its stree allocation map. A user or automounter must mount the image; later file allocation can expose kernel heap data, corrupt allocation state, or panic the system.
Summary
What happened
Out-of-bounds access in Linux JFS allows attackers to corrupt kernel memory and crash the system via a crafted filesystem image. dbMount accepts unvalidated db_agheight, db_agwidth, and db_agstart metadata, allowing dbAllocAG to perform a negative shift and index beyond its stree allocation map. A user or automounter must mount the image; later file allocation can expose kernel heap data, corrupt allocation state, or panic the system.
The record
- CVE
- CVE-2025-38230
- Published
- Jul 4, 2025
- Updated
- Aug 5, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1204.002
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 4, 2025CVE publishedPublication date reported by the CVE source.
- Aug 5, 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=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <0c40fa81f850556e9aa0185fede9ef1112db7b39
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <37bfb464ddca87f203071b5bd562cd91ddc0b40a
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <8b69608c6b6779a7ab07ce4467a56df90152cfb9
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <9242ff6245527a3ebb693ddd175493b38ddca72f
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <95ae5ee6069d9a5945772625f289422ef659221a
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <a4259e72363e1ea204a97292001a9fc36c7e52fd
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <b62a1e59d8716bbd2e73660743fe06acc97ed7d1
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <c3705c82b7406a15ef38a610d03bf6baa43d6e0c
- Affected versionversion=2.6.12
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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