Thread scheduling delays via busy-waiting qed trace reads
Published Oct 1, 2025 · Updated Oct 1, 2025
Denial of service in the Linux kernel allows local users to delay thread scheduling by requesting a qed device trace through ethtool. The qed_mcp_cmd_and_union loop busy-waits in 10-microsecond intervals during NVM reads and can hold the current thread for more than five seconds because the trace path does not permit sleeping. Local access sufficient to issue the ethtool request is required, and the demonstrated consequence is prolonged scheduler latency rather than data disclosure or modification.
Summary
What happened
Denial of service in the Linux kernel allows local users to delay thread scheduling by requesting a qed device trace through ethtool. The qed_mcp_cmd_and_union loop busy-waits in 10-microsecond intervals during NVM reads and can hold the current thread for more than five seconds because the trace path does not permit sleeping. Local access sufficient to issue the ethtool request is required, and the demonstrated consequence is prolonged scheduler latency rather than data disclosure or modification.
The record
- CVE
- CVE-2023-53509
- Published
- Oct 1, 2025
- Updated
- Oct 1, 2025
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1499
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Oct 1, 2025CVE publishedPublication date reported by the CVE source.
- Oct 1, 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?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=4.9
- Affected versionversion=c965db44462919f613973aa618271f6c3f5a1e64 <50c81b35df01db12b348c5cbf4b1917dc9a7db54
- Affected versionversion=c965db44462919f613973aa618271f6c3f5a1e64 <5401c3e0992860b11fb4b25796e4c4f1921740df
- Affected versionversion=c965db44462919f613973aa618271f6c3f5a1e64 <e0387f4f39a8d92302273ac356d1f6b2a38160d8
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What is affected?
Published CVSS scores
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Attacks
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Weakness, pattern, technique
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Technologies
Your stack
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Your stack
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