Local kernel memory corruption via stale device pointer
Published Jul 12, 2024 · Updated Aug 5, 2026
Use-after-free in Linux btrfs allows local users to corrupt kernel memory during concurrent zoned-filesystem device replacement. The btrfs_load_zone_info() path keeps a device pointer taken from the chunk map outside the device-replace rwsem, so replacement can free the device before the function finishes using it. Reachability requires low-privileged local write access to a mounted zoned btrfs filesystem while source-device replacement and block-group creation overlap.
Summary
What happened
Use-after-free in Linux btrfs allows local users to corrupt kernel memory during concurrent zoned-filesystem device replacement. The btrfs_load_zone_info() path keeps a device pointer taken from the chunk map outside the device-replace rwsem, so replacement can free the device before the function finishes using it. Reachability requires low-privileged local write access to a mounted zoned btrfs filesystem while source-device replacement and block-group creation overlap.
The record
- CVE
- CVE-2024-39496
- Published
- Jul 12, 2024
- Updated
- Aug 5, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-416, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 12, 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?
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- Affected versionversion=5.11
- Affected versionversion=5b316468983dfa9473ff0f1c42e4e30b4c267141 <0090d6e1b210551e63cf43958dc7a1ec942cdde9
- Affected versionversion=5b316468983dfa9473ff0f1c42e4e30b4c267141 <092571ef9a812566c8f2c9038d9c2a64c49788d6
- Affected versionversion=5b316468983dfa9473ff0f1c42e4e30b4c267141 <17765964703b88d8befd899f8501150bb7e07e43
- Affected versionversion=5b316468983dfa9473ff0f1c42e4e30b4c267141 <a0cc006f4214b87e70983c692e05bb36c59b5752
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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Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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