{"api_version":"1","generated_at":"2026-07-23T14:11:42+00:00","cve":"CVE-2026-64070","urls":{"html":"https://cve.report/CVE-2026-64070","api":"https://cve.report/api/cve/CVE-2026-64070.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-64070","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-64070"},"summary":{"title":"powerpc/hv-gpci: fix preempt count leak in sysfs show paths","description":"In the Linux kernel, the following vulnerability has been resolved:\n\npowerpc/hv-gpci: fix preempt count leak in sysfs show paths\n\nFour sysfs show() callbacks in hv-gpci take get_cpu_var(hv_gpci_reqb)\n(which calls preempt_disable()) but only call the matching put_cpu_var()\non the error path under the 'out:' label. Every successful read leaks\none preempt_disable():\n\n  processor_bus_topology_show()\n  processor_config_show()\n  affinity_domain_via_virtual_processor_show()\n  affinity_domain_via_domain_show()\n\n(affinity_domain_via_partition_show() was already correct.)\n\nOn a CONFIG_PREEMPT=y kernel, repeated reads raise preempt_count and\neventually return to userspace with preemption still disabled. The\nnext user-mode page fault then hits faulthandler_disabled() == 1,\ngets forced to SIGSEGV, and the resulting coredump trips\n'BUG: scheduling while atomic' in call_usermodehelper_exec ->\nwait_for_completion_state -> schedule:\n\n  BUG: scheduling while atomic: <task>/<pid>/0x00000004\n  ...\n  __schedule_bug+0x6c/0x90\n  __schedule+0x58c/0x13a0\n  schedule+0x48/0x1a0\n  schedule_timeout+0x104/0x170\n  wait_for_completion_state+0x16c/0x330\n  call_usermodehelper_exec+0x254/0x2d0\n  vfs_coredump+0x1050/0x2590\n  get_signal+0xb9c/0xc80\n  do_notify_resume+0xf8/0x470\n\nAdd an out_success label that calls put_cpu_var() before returning\nthe byte count, mirroring affinity_domain_via_partition_show().","state":"PUBLISHED","assigner":"Linux","published_at":"2026-07-19 16:17:47","updated_at":"2026-07-19 16:17:47"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/903409000a07ac8e31ffedeb8516f4f8d67150c8","name":"https://git.kernel.org/stable/c/903409000a07ac8e31ffedeb8516f4f8d67150c8","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/dbc30a57bd8e026995e9fa8e8c31cffd18542c01","name":"https://git.kernel.org/stable/c/dbc30a57bd8e026995e9fa8e8c31cffd18542c01","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-64070","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-64070","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 71f1c39647d8c9d4d54a861ec81f1ff17544bcb6 903409000a07ac8e31ffedeb8516f4f8d67150c8 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 71f1c39647d8c9d4d54a861ec81f1ff17544bcb6 dbc30a57bd8e026995e9fa8e8c31cffd18542c01 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.6","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.0.11 7.0.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"64070","cve":"CVE-2026-64070","epss":"0.001550000","percentile":"0.051010000","score_date":"2026-07-20","updated_at":"2026-07-21 00:13:14"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["arch/powerpc/perf/hv-gpci.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"903409000a07ac8e31ffedeb8516f4f8d67150c8","status":"affected","version":"71f1c39647d8c9d4d54a861ec81f1ff17544bcb6","versionType":"git"},{"lessThan":"dbc30a57bd8e026995e9fa8e8c31cffd18542c01","status":"affected","version":"71f1c39647d8c9d4d54a861ec81f1ff17544bcb6","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["arch/powerpc/perf/hv-gpci.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"6.6"},{"lessThan":"6.6","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"7.0.*","status":"unaffected","version":"7.0.11","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.1","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.0.11","versionStartIncluding":"6.6","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1","versionStartIncluding":"6.6","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\npowerpc/hv-gpci: fix preempt count leak in sysfs show paths\n\nFour sysfs show() callbacks in hv-gpci take get_cpu_var(hv_gpci_reqb)\n(which calls preempt_disable()) but only call the matching put_cpu_var()\non the error path under the 'out:' label. Every successful read leaks\none preempt_disable():\n\n  processor_bus_topology_show()\n  processor_config_show()\n  affinity_domain_via_virtual_processor_show()\n  affinity_domain_via_domain_show()\n\n(affinity_domain_via_partition_show() was already correct.)\n\nOn a CONFIG_PREEMPT=y kernel, repeated reads raise preempt_count and\neventually return to userspace with preemption still disabled. The\nnext user-mode page fault then hits faulthandler_disabled() == 1,\ngets forced to SIGSEGV, and the resulting coredump trips\n'BUG: scheduling while atomic' in call_usermodehelper_exec ->\nwait_for_completion_state -> schedule:\n\n  BUG: scheduling while atomic: <task>/<pid>/0x00000004\n  ...\n  __schedule_bug+0x6c/0x90\n  __schedule+0x58c/0x13a0\n  schedule+0x48/0x1a0\n  schedule_timeout+0x104/0x170\n  wait_for_completion_state+0x16c/0x330\n  call_usermodehelper_exec+0x254/0x2d0\n  vfs_coredump+0x1050/0x2590\n  get_signal+0xb9c/0xc80\n  do_notify_resume+0xf8/0x470\n\nAdd an out_success label that calls put_cpu_var() before returning\nthe byte count, mirroring affinity_domain_via_partition_show()."}],"providerMetadata":{"dateUpdated":"2026-07-19T15:39:46.536Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/903409000a07ac8e31ffedeb8516f4f8d67150c8"},{"url":"https://git.kernel.org/stable/c/dbc30a57bd8e026995e9fa8e8c31cffd18542c01"}],"title":"powerpc/hv-gpci: fix preempt count leak in sysfs show paths","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-64070","datePublished":"2026-07-19T15:39:46.536Z","dateReserved":"2026-07-19T07:54:57.030Z","dateUpdated":"2026-07-19T15:39:46.536Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-07-19 16:17:47","lastModifiedDate":"2026-07-19 16:17:47","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"64070","Ordinal":"1","Title":"powerpc/hv-gpci: fix preempt count leak in sysfs show paths","CVE":"CVE-2026-64070","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"64070","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\npowerpc/hv-gpci: fix preempt count leak in sysfs show paths\n\nFour sysfs show() callbacks in hv-gpci take get_cpu_var(hv_gpci_reqb)\n(which calls preempt_disable()) but only call the matching put_cpu_var()\non the error path under the 'out:' label. Every successful read leaks\none preempt_disable():\n\n  processor_bus_topology_show()\n  processor_config_show()\n  affinity_domain_via_virtual_processor_show()\n  affinity_domain_via_domain_show()\n\n(affinity_domain_via_partition_show() was already correct.)\n\nOn a CONFIG_PREEMPT=y kernel, repeated reads raise preempt_count and\neventually return to userspace with preemption still disabled. The\nnext user-mode page fault then hits faulthandler_disabled() == 1,\ngets forced to SIGSEGV, and the resulting coredump trips\n'BUG: scheduling while atomic' in call_usermodehelper_exec ->\nwait_for_completion_state -> schedule:\n\n  BUG: scheduling while atomic: <task>/<pid>/0x00000004\n  ...\n  __schedule_bug+0x6c/0x90\n  __schedule+0x58c/0x13a0\n  schedule+0x48/0x1a0\n  schedule_timeout+0x104/0x170\n  wait_for_completion_state+0x16c/0x330\n  call_usermodehelper_exec+0x254/0x2d0\n  vfs_coredump+0x1050/0x2590\n  get_signal+0xb9c/0xc80\n  do_notify_resume+0xf8/0x470\n\nAdd an out_success label that calls put_cpu_var() before returning\nthe byte count, mirroring affinity_domain_via_partition_show().","Type":"Description","Title":"powerpc/hv-gpci: fix preempt count leak in sysfs show paths"}]}}}