System crash via stale Btrfs relocation pointer
Published Jun 5, 2023 · Updated Apr 23, 2025
Use-after-free in Linux Kernel Btrfs before 6.0-rc2 allows local users to crash the system through balance and defrag ioctls. On transaction-commit failure, prepare_to_relocate leaves fs_info->reloc_ctl pointing to a freed relocation-control structure that btrfs_init_reloc_root later dereferences. Exploitation requires local access, Btrfs balance before defrag, and the intervening commit failure; the bounded reported consequence is a system crash.
Summary
What happened
Use-after-free in Linux Kernel Btrfs before 6.0-rc2 allows local users to crash the system through balance and defrag ioctls. On transaction-commit failure, prepare_to_relocate leaves fs_info->reloc_ctl pointing to a freed relocation-control structure that btrfs_init_reloc_root later dereferences. Exploitation requires local access, Btrfs balance before defrag, and the intervening commit failure; the bounded reported consequence is a system crash.
The record
- CVE
- CVE-2023-3111
- Published
- Jun 5, 2023
- Updated
- Apr 23, 2025
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- CWE-416, T1499
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jun 5, 2023CVE publishedPublication date reported by the CVE source.
- Apr 23, 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?
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- Affected versionversion=Kernel version prior to Kernel 6.0-rc2
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
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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