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CVE-2026-64070

In the Linux kernel, the following vulnerability has been resolved: powerpc/hv-gpci: fix preempt count leak in sysfs show paths Four sysfs show() callbacks in hv-gpci take get_cpu_var(hv_gpci_req…

Published Jul 19, 2026EPSS 0.12%

Overview

CVE-2026-64070 is a known-severity vulnerability. It was published on July 19, 2026.

Technical description

In the Linux kernel, the following vulnerability has been resolved:

powerpc/hv-gpci: fix preempt count leak in sysfs show paths

Four sysfs show() callbacks in hv-gpci take get_cpu_var(hv_gpci_reqb)

(which calls preempt_disable()) but only call the matching put_cpu_var()

on the error path under the 'out:' label. Every successful read leaks

one preempt_disable():

processor_bus_topology_show()

processor_config_show()

affinity_domain_via_virtual_processor_show()

affinity_domain_via_domain_show()

(affinity_domain_via_partition_show() was already correct.)

On a CONFIG_PREEMPT=y kernel, repeated reads raise preempt_count and

eventually return to userspace with preemption still disabled. The

next user-mode page fault then hits faulthandler_disabled() == 1,

gets forced to SIGSEGV, and the resulting coredump trips

'BUG: scheduling while atomic' in call_usermodehelper_exec ->

wait_for_completion_state -> schedule:

BUG: scheduling while atomic: <task>/<pid>/0x00000004

...

__sch

Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

Frequently asked questions

What is CVE-2026-64070?

CVE-2026-64070 is a known-severity vulnerability. It was published on July 19, 2026.

How severe is CVE-2026-64070?

CVSS score information is not yet available for this vulnerability. Check back as the CVE record is updated by NVD analysts.

How do I fix or remediate CVE-2026-64070?

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

How can CyberStrike help with CVE-2026-64070?

CyberStrike is an open-source, AI-augmented pentesting engine. Rather than flag a version number, it tests whether an issue like CVE-2026-64070 is actually reachable in your own applications and APIs, then verifies each finding before reporting it. That tells you if the weakness is a real, exploitable risk in your environment or a false positive you can safely deprioritize.