Kernel-memory disclosure via uncleared fast-commit journal space
Published Oct 1, 2025 · Updated Oct 1, 2025
Information disclosure in the ext4 fast-commit journal in Linux allows local users to cause uninitialized kernel memory to be written to disk. The ext4_fc_reserve_space and ext4_fc_write_tail paths submit journal blocks without clearing the unused final byte or the space following the tail checksum. Exploitation requires local low-privileged access and an ext4 filesystem using fast commits; the exposed bytes remain in journal storage rather than being returned directly to the user.
Summary
What happened
Information disclosure in the ext4 fast-commit journal in Linux allows local users to cause uninitialized kernel memory to be written to disk. The ext4_fc_reserve_space and ext4_fc_write_tail paths submit journal blocks without clearing the unused final byte or the space following the tail checksum. Exploitation requires local low-privileged access and an ext4 filesystem using fast commits; the exposed bytes remain in journal storage rather than being returned directly to the user.
The record
- CVE
- CVE-2022-50465
- Published
- Oct 1, 2025
- Updated
- Oct 1, 2025
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-401
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Oct 1, 2025CVE publishedPublication date reported by the CVE source.
- Oct 1, 2025Record 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=5.10
- Affected versionversion=aa75f4d3daaeb1389b9cce9d6b84401eaf228d4e <594bc43b410316d70bb42aeff168837888d96810
- Affected versionversion=aa75f4d3daaeb1389b9cce9d6b84401eaf228d4e <7c1fb65e8ce85c281d2cba9c236f9edbbc4eaca6
- Affected versionversion=aa75f4d3daaeb1389b9cce9d6b84401eaf228d4e <871800770d7f2f952c7249ad52485c3564dab44e
- Affected versionversion=aa75f4d3daaeb1389b9cce9d6b84401eaf228d4e <b8b7922374b00a44137e5bcdd46ef86c8b065f27
- Affected versionversion=aa75f4d3daaeb1389b9cce9d6b84401eaf228d4e <d9ba03eb03dc2dccb5450de388ea46bdcaaf8348
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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Your stack
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