Kernel crash via duplicate DNS key insertion
Published Dec 30, 2025 · Updated Dec 30, 2025
Race condition in the Linux kernel allows local users to crash the system by provoking concurrent equivalent DNS resolver queries. During request_key_and_link, exact assoc_array comparison and DNS resolver matching disagree, allowing equivalent names to be linked as duplicate index keys. The race requires overlapping in-kernel lookups such as CIFS hostname resolution, and the resulting BUG_ON interrupts the entire host.
Summary
What happened
Race condition in the Linux kernel allows local users to crash the system by provoking concurrent equivalent DNS resolver queries. During request_key_and_link, exact assoc_array comparison and DNS resolver matching disagree, allowing equivalent names to be linked as duplicate index keys. The race requires overlapping in-kernel lookups such as CIFS hostname resolution, and the resulting BUG_ON interrupts the entire host.
The record
- CVE
- CVE-2023-54170
- Published
- Dec 30, 2025
- Updated
- Dec 30, 2025
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1499
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Dec 30, 2025CVE publishedPublication date reported by the CVE source.
- Dec 30, 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=5.3
- Affected versionversion=df593ee23e05cdda16c8c995e5818779431bb29f <00edfa6d4fe022942e2f2e6f3294ff13ef78b15c
- Affected versionversion=df593ee23e05cdda16c8c995e5818779431bb29f <0a6b0ca58685be34979236f83f2b322635b80b32
- Affected versionversion=df593ee23e05cdda16c8c995e5818779431bb29f <65bd66a794bfa059375ec834885bb610d75c0182
- Affected versionversion=df593ee23e05cdda16c8c995e5818779431bb29f <9aecfebea24fe6071ace5cc9fd6d690b87276bbb
- Affected versionversion=df593ee23e05cdda16c8c995e5818779431bb29f <d55901522f96082a43b9842d34867363c0cdbac5
- Affected versionversion=df593ee23e05cdda16c8c995e5818779431bb29f <e091bb55af9a930801f83df78195a908a76e1479
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
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Technologies
Your stack
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Your stack
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