Kernel memory disclosure and panic via unchecked PTFF
Published Aug 10, 2026 · Updated Aug 10, 2026
Improper hardware validation in Linux ptp_s390 allows local users to leak kernel memory or panic the host through PTP device calls. The driver registers its physical clock without confirming facility 28 and PTFF QPT support, then ptp_s390_qpt_gettime() executes PTFF and returns unchecked stack data. An affected IBM Z system must expose the s390 PTP character device; read ioctls require no CAP_SYS_TIME privilege.
Summary
What happened
Improper hardware validation in Linux ptp_s390 allows local users to leak kernel memory or panic the host through PTP device calls. The driver registers its physical clock without confirming facility 28 and PTFF QPT support, then ptp_s390_qpt_gettime() executes PTFF and returns unchecked stack data. An affected IBM Z system must expose the s390 PTP character device; read ioctls require no CAP_SYS_TIME privilege.
The record
- CVE
- CVE-2026-68134
- Published
- Aug 10, 2026
- Updated
- Aug 10, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-280, T1499.004
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Aug 10, 2026CVE publishedPublication date reported by the CVE source.
- Aug 10, 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=2d7de7a3010d713fb89b7ba99e6fdc14475ad106 <545a7fdbc110c82933d448db2695abff07536f08
- Affected versionversion=2d7de7a3010d713fb89b7ba99e6fdc14475ad106 <b3efb4744abf493c9782eae713b861a80d9bbeca
- Affected versionversion=2d7de7a3010d713fb89b7ba99e6fdc14475ad106 <e78f1ac37afcb16cb6fef8a2c92591eab6558956
- Affected versionversion=6.13
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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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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