Local privilege escalation via unchecked JFS indexes
Published May 21, 2024 · Updated Aug 5, 2026
Out-of-bounds access in Linux JFS allows local users to gain kernel privileges by mounting a crafted filesystem image. The JFS block-map code accepts out-of-range db_maxag and db_agpref values that later index the fixed-size db_agfree array during allocation. This local path can corrupt or disclose adjacent kernel heap memory or crash the host without separate user interaction.
Summary
What happened
Out-of-bounds access in Linux JFS allows local users to gain kernel privileges by mounting a crafted filesystem image. The JFS block-map code accepts out-of-range db_maxag and db_agpref values that later index the fixed-size db_agfree array during allocation. This local path can corrupt or disclose adjacent kernel heap memory or crash the host without separate user interaction.
The record
- CVE
- CVE-2023-52804
- Published
- May 21, 2024
- Updated
- Aug 5, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-129, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- May 21, 2024CVE 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 <1f74d336990f37703a8eee77153463d65b67f70e
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <2323de34a3ae61a9f9b544c18583f71cea86721f
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <32bd8f1cbcf8b663e29dd1f908ba3a129541a11b
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <5013f8269887642cca784adc8db9b5f0b771533f
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <64933ab7b04881c6c18b21ff206c12278341c72e
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <a0649e2dd4a3595b5595a29d0064d047c2fae2fb
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <c6c8863fb3f57700ab583d875adda04caaf2278a
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <ce15b0f1a431168f07b1cc6c9f71206a2db5c809
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <dca403bb035a565bb98ecc1dda5d30f676feda40
- Affected versionversion=2.6.12
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
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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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