{"id":"CVE-2026-68134","state":"PUBLISHED","title":"ptp: ptp_s390: Add missing facility check","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nptp: ptp_s390: Add missing facility check\n\nOnly register the physical clock when facility 28 is installed\nand PTFF QAF returns that PTFF QPT is available.","publishedAt":"2026-08-10T11:58:57.504Z","updatedAt":"2026-08-17T04:59:26.371Z","severity":{"score":7.3,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"2d7de7a3010d713fb89b7ba99e6fdc14475ad106","status":"affected","lessThan":"b3efb4744abf493c9782eae713b861a80d9bbeca","versionType":"git"},{"version":"2d7de7a3010d713fb89b7ba99e6fdc14475ad106","status":"affected","lessThan":"545a7fdbc110c82933d448db2695abff07536f08","versionType":"git"},{"version":"2d7de7a3010d713fb89b7ba99e6fdc14475ad106","status":"affected","lessThan":"e78f1ac37afcb16cb6fef8a2c92591eab6558956","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/ptp/ptp_s390.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.13","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.13","versionType":"semver"},{"version":"6.18.42","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.6","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/ptp/ptp_s390.c"]}],"references":["https://git.kernel.org/stable/c/b3efb4744abf493c9782eae713b861a80d9bbeca","https://git.kernel.org/stable/c/545a7fdbc110c82933d448db2695abff07536f08","https://git.kernel.org/stable/c/e78f1ac37afcb16cb6fef8a2c92591eab6558956"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:49.727Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/68xxx/CVE-2026-68134.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-68134","state":"PUBLISHED","datePublished":"2026-08-10T11:58:57.504Z","dateUpdated":"2026-08-17T04:59:26.371Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-07-30T09:28:09.370Z"},"containers":{"cna":{"title":"ptp: ptp_s390: Add missing facility check","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nptp: ptp_s390: Add missing facility check\n\nOnly register the physical clock when facility 28 is installed\nand PTFF QAF returns that PTFF QPT is available."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"2d7de7a3010d713fb89b7ba99e6fdc14475ad106","status":"affected","lessThan":"b3efb4744abf493c9782eae713b861a80d9bbeca","versionType":"git"},{"version":"2d7de7a3010d713fb89b7ba99e6fdc14475ad106","status":"affected","lessThan":"545a7fdbc110c82933d448db2695abff07536f08","versionType":"git"},{"version":"2d7de7a3010d713fb89b7ba99e6fdc14475ad106","status":"affected","lessThan":"e78f1ac37afcb16cb6fef8a2c92591eab6558956","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/ptp/ptp_s390.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.13","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.13","versionType":"semver"},{"version":"6.18.42","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.6","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/ptp/ptp_s390.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/b3efb4744abf493c9782eae713b861a80d9bbeca"},{"url":"https://git.kernel.org/stable/c/545a7fdbc110c82933d448db2695abff07536f08"},{"url":"https://git.kernel.org/stable/c/e78f1ac37afcb16cb6fef8a2c92591eab6558956"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H","baseScore":7.3,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The bug is reached only via local PTP character-device access: open(/dev/ptpX) followed by ioctl paths such as PTP_SYS_OFFSET or clock_gettime on the posix clock FD, which call ptp_s390_qpt_gettime() and execute the PTFF instruction in kernel context.\nAC:L - On affected IBM Z systems with the s390 PTP driver enabled, any process that can open the physical-clock device can repeatedly issue read ioctls that deterministically invoke PTFF without races or attacker-uncontrollable timing.\nPR:L - PTP read ioctls and clock_gettime do not require CAP_SYS_TIME; on typical chrony/ptp4l and containerized time-sync deployments /dev/ptp* is often opened by non-root service accounts or passed into unprivileged workloads, not only init-namespace root.\nUI:N - Exploitation requires only the attacker (or their service account) opening the PTP device and issuing ioctls; no separate victim action such as mounting a filesystem or clicking a prompt is needed.\nS:U - Impact is confined to the same Linux kernel running the ptp_s390 driver on the s390 host; it does not cross a VM, IOMMU, or other security boundary to another authority.\nC:H - When PTFF QPT is unavailable the driver still calls ptff() and returns the unchecked stack buffer to userspace, leaking kernel memory; on systems without facility 28 the illegal PTFF traps in kernel mode and can expose register/state data during the fault path.\nI:L - Returning attacker-influenced or uninitialized PTFF output as authoritative PTP time via ioctl can corrupt time-sync decisions for chrony/ptp4l and other consumers that steer system clocks from the physical-clock device.\nA:H - Executing PTFF without facility 28 or on unsupported configurations triggers an s390 program check in kernel context (illegal/specification exception) that ends in die(), causing a kernel oops/panic and total loss of host availability."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-17T04:59:26.371Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.13","versionEndExcluding":"6.18.42"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.13","versionEndExcluding":"7.1.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.13","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}