Task hang via reentrant extent locking
Published May 17, 2024 · Updated May 11, 2026
Improper locking in Linux Btrfs 2.6.29 through 6.6.23, 6.7 through 6.7.11, and 6.8-rc1 through 6.8-rc5 allows local users to hang tasks. The btrfs fiemap path holds an extent-range lock while copying each extent to user space, where a page fault can reenter btrfs_page_mkwrite on the same mapped file and wait on that lock. A local user must invoke fiemap on a memory-mapped Btrfs file and trigger a write fault; the affected task deadlocks without reported data disclosure or modification.
Summary
What happened
Improper locking in Linux Btrfs 2.6.29 through 6.6.23, 6.7 through 6.7.11, and 6.8-rc1 through 6.8-rc5 allows local users to hang tasks. The btrfs fiemap path holds an extent-range lock while copying each extent to user space, where a page fault can reenter btrfs_page_mkwrite on the same mapped file and wait on that lock. A local user must invoke fiemap on a memory-mapped Btrfs file and trigger a write fault; the affected task deadlocks without reported data disclosure or modification.
The record
- CVE
- CVE-2024-35784
- Published
- May 17, 2024
- Updated
- May 11, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-667, T1499.004
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- May 17, 2024CVE publishedPublication date reported by the CVE source.
- May 11, 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=1506fcc8189cdd4b95e06df7845a09f18b4526a6 <89bca7fe6382d61e88c67a0b0e7bce315986fb8b
- Affected versionversion=1506fcc8189cdd4b95e06df7845a09f18b4526a6 <b0ad381fa7690244802aed119b478b4bdafc31dd
- Affected versionversion=1506fcc8189cdd4b95e06df7845a09f18b4526a6 <ded566b4637f1b6b4c9ba74e7d0b8493e93f19cf
- Affected versionversion=2.6.29
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
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Public exploit references
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Technologies
Your stack
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Your stack
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