Crash and kernel disclosure via JFS log race
Published Nov 1, 2023 · Updated Nov 20, 2025
Use-after-free in Linux kernel JFS 6.3.0 allows local users to crash the system or read internal kernel information via a race. During JFS teardown, lmLogClose clears and frees the superblock's log object while txEnd can retain that pointer and clear log_FLUSH through freed memory. Normal local privileges are sufficient, but exploitation depends on winning the cross-thread timing window; the documented results are a kernel crash or disclosure of internal kernel information.
Summary
What happened
Use-after-free in Linux kernel JFS 6.3.0 allows local users to crash the system or read internal kernel information via a race. During JFS teardown, lmLogClose clears and frees the superblock's log object while txEnd can retain that pointer and clear log_FLUSH through freed memory. Normal local privileges are sufficient, but exploitation depends on winning the cross-thread timing window; the documented results are a kernel crash or disclosure of internal kernel information.
The record
- CVE
- CVE-2023-3397
- Published
- Nov 1, 2023
- Updated
- Nov 20, 2025
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-362, CWE-416, T1499
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Nov 1, 2023CVE publishedPublication date reported by the CVE source.
- Nov 20, 2025Record updatedLatest update available in the CVE record.
Exploitability
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What is affected?
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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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Your stack
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