Local denial of service via zero-length iomap
Published Feb 26, 2025 · Updated May 11, 2026
Denial of service in Linux zonefs allows local users to hang readahead by reading a sequential zone file exactly at its current size. The zonefs_iomap_begin() read path labels that EOF request IOMAP_UNWRITTEN but returns a zero-length mapping, so iomap_readahead_iter() repeatedly returns without advancing. Exploitation requires local read access to a sequential file on a mounted zonefs instance, and the affected read remains stuck while consuming kernel execution time.
Summary
What happened
Denial of service in Linux zonefs allows local users to hang readahead by reading a sequential zone file exactly at its current size. The zonefs_iomap_begin() read path labels that EOF request IOMAP_UNWRITTEN but returns a zero-length mapping, so iomap_readahead_iter() repeatedly returns without advancing. Exploitation requires local read access to a sequential file on a mounted zonefs instance, and the affected read remains stuck while consuming kernel execution time.
The record
- CVE
- CVE-2022-49706
- Published
- Feb 26, 2025
- Updated
- May 11, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-125, T1499
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Feb 26, 2025CVE 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=5.6
- Affected versionversion=8dcc1a9d90c10fa4143e5c17821082e5e60e46a1 <355be6131164c5bacf2e810763835aecb6e01fcb
- Affected versionversion=8dcc1a9d90c10fa4143e5c17821082e5e60e46a1 <3a7f05f104347b407e865c10be2675cd833a4e48
- Affected versionversion=8dcc1a9d90c10fa4143e5c17821082e5e60e46a1 <c1c1204c0d0c1dccc1310b9277fb2bd8b663d8fe
- Affected versionversion=8dcc1a9d90c10fa4143e5c17821082e5e60e46a1 <c2f71b9bb398e2e573bdc2574149f42b45efe410
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
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Technologies
Your stack
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Your stack
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