{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-64070", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T07:54:57.030Z", "datePublished": "2026-07-19T15:39:46.536Z", "dateUpdated": "2026-07-19T15:39:46.536Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-07-19T15:39:46.536Z"}, "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()."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["arch/powerpc/perf/hv-gpci.c"], "versions": [{"version": "71f1c39647d8c9d4d54a861ec81f1ff17544bcb6", "lessThan": "903409000a07ac8e31ffedeb8516f4f8d67150c8", "status": "affected", "versionType": "git"}, {"version": "71f1c39647d8c9d4d54a861ec81f1ff17544bcb6", "lessThan": "dbc30a57bd8e026995e9fa8e8c31cffd18542c01", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["arch/powerpc/perf/hv-gpci.c"], "versions": [{"version": "6.6", "status": "affected"}, {"version": "0", "lessThan": "6.6", "status": "unaffected", "versionType": "semver"}, {"version": "7.0.11", "lessThanOrEqual": "7.0.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.1", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.6", "versionEndExcluding": "7.0.11"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.6", "versionEndExcluding": "7.1"}]}]}], "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"}}}}

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{}

{"bugzilla": {"description": "kernel: powerpc/hv-gpci: fix preempt count leak in sysfs show paths", "id": "2502611", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2502611"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.5", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-772", "details": ["A flaw was found in the Linux kernel's powerpc/hv-gpci component. This vulnerability allows a local attacker to cause a denial of service (DoS) by repeatedly reading from specific sysfs files. The flaw is due to a preemption count leak, where successful reads from sysfs show functions fail to re-enable preemption. This can lead to a 'scheduling while atomic' bug, causing a system crash and coredump."], "name": "CVE-2026-64070", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Fix deferred", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/a:redhat:hummingbird:1", "fix_state": "Fix deferred", "impact": "moderate", "package_name": "erlang27", "product_name": "Red Hat Hardened Images"}], "public_date": "2026-07-19T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-64070\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-64070\nhttps://lore.kernel.org/linux-cve-announce/2026071913-CVE-2026-64070-6db2@gregkh/T"], "threat_severity": "Low"}

{}