PTP operation hang via recursive mutex acquisition
Published Jul 10, 2025 · Updated May 11, 2026
Deadlock in affected Linux kernels from 5.14 allows local users to hang PTP clock operations through virtual-clock reconfiguration. In drivers/ptp/ptp_private.h, ptp_vclock_in_use() acquires n_vclocks_mux to read n_vclocks even when n_vclocks_store() already holds that mutex. A local user needs permission to change the PTP virtual-clock count; the recursive acquisition blocks the affected clock-unregister path without disclosing or modifying data.
Summary
What happened
Deadlock in affected Linux kernels from 5.14 allows local users to hang PTP clock operations through virtual-clock reconfiguration. In drivers/ptp/ptp_private.h, ptp_vclock_in_use() acquires n_vclocks_mux to read n_vclocks even when n_vclocks_store() already holds that mutex. A local user needs permission to change the PTP virtual-clock count; the recursive acquisition blocks the affected clock-unregister path without disclosing or modifying data.
The record
- CVE
- CVE-2025-38305
- Published
- Jul 10, 2025
- Updated
- May 11, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1499.004
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 10, 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?
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- Affected versionversion=5.14
- Affected versionversion=73f37068d540eba5f93ba3a0019bf479d35ebd76 <259119595227fd20f6aa29d85abe086b6fdd9eb1
- Affected versionversion=73f37068d540eba5f93ba3a0019bf479d35ebd76 <5d217e7031a5c06d366580fc6ddbf43527b780d4
- Affected versionversion=73f37068d540eba5f93ba3a0019bf479d35ebd76 <87f7ce260a3c838b49e1dc1ceedf1006795157a2
- Affected versionversion=73f37068d540eba5f93ba3a0019bf479d35ebd76 <b1b73c452331451020be3bf4b014901015ae6663
- Affected versionversion=73f37068d540eba5f93ba3a0019bf479d35ebd76 <b93e6fef4eda48e17d9c642b9abad98a066fd4a3
- Affected versionversion=73f37068d540eba5f93ba3a0019bf479d35ebd76 <ef8fc007c28a30a4c0d90bf755e0f343d99bb392
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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
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