Local denial of service via resync counter race
Published Oct 7, 2025 · Updated Oct 7, 2025
Denial of service in the Linux kernel md subsystem allows local users to cause a CPU soft lockup while array resync status is read. The status_resync function subtracts concurrently updated curr_resync and recovery_active counters without synchronization, so underflow produces a huge loop bound for progress-bar output. A low-privileged local user must reach md resync status reporting; the documented consequence is processor lockup and service interruption, not data disclosure or modification.
Summary
What happened
Denial of service in the Linux kernel md subsystem allows local users to cause a CPU soft lockup while array resync status is read. The status_resync function subtracts concurrently updated curr_resync and recovery_active counters without synchronization, so underflow produces a huge loop bound for progress-bar output. A low-privileged local user must reach md resync status reporting; the documented consequence is processor lockup and service interruption, not data disclosure or modification.
The record
- CVE
- CVE-2023-53620
- Published
- Oct 7, 2025
- Updated
- Oct 7, 2025
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-667, T1499
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Oct 7, 2025CVE publishedPublication date reported by the CVE source.
- Oct 7, 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=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <23309704e90859af2662bedc44101e6d1d2ece7e
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <6efddf1e32e2a264694766ca485a4f5e04ee82a7
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <b4acb6c3ede88d6b7d33742a09e63cfce5e7fb69
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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