Filesystem hang via reversed inode lock order
Published Jan 31, 2026 · Updated Jan 31, 2026
ABBA deadlock in btrfs in Linux Kernel 6.13 allows attackers to hang filesystem operations via unspecified vectors. On the failure path, btrfs_read_locked_inode calls iget_failed before releasing its read-locked leaf; inode eviction then reverses the delayed-node and btree lock order. The trigger requires a failed inode lookup, and published material establishes neither attacker privileges nor remote reachability; the bounded consequence is a filesystem hang.
Summary
What happened
ABBA deadlock in btrfs in Linux Kernel 6.13 allows attackers to hang filesystem operations via unspecified vectors. On the failure path, btrfs_read_locked_inode calls iget_failed before releasing its read-locked leaf; inode eviction then reverses the delayed-node and btree lock order. The trigger requires a failed inode lookup, and published material establishes neither attacker privileges nor remote reachability; the bounded consequence is a filesystem hang.
The record
- CVE
- CVE-2026-23036
- Published
- Jan 31, 2026
- Updated
- Jan 31, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- T1499.004
- Attack vector
- Unavailable
- Privileges
- Unavailable
Timeline
How it unfolded
- Jan 31, 2026CVE publishedPublication date reported by the CVE source.
- Jan 31, 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=6.13
- Affected versionversion=69673992b1aea5540199d9b8b658ede72f55a6cf <1e1f2055ad5a7a5d548789b334a4473a7665c418
- Affected versionversion=69673992b1aea5540199d9b8b658ede72f55a6cf <65241e3ddda60b53a4ee3ae12721fc9ee21d5827
What conditions does exploitation require?
What is affected?
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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