The kernel’s cpuhp_invoke_callback() function mistakenly reuses a return value when an earlier hotplug callback fails, overwriting the original error code and making the operation appear successful. This flaw falls under CWE-393 (incorrect error handling). As a result, the system may silently lose CPUs or report wrong hotplug states.

All Linux kernel releases that have not yet incorporated the commit that fixes this rollback path are vulnerable. No specific version ranges are published, so any unpatched kernel across all Linux distributions is considered at risk.

With a CVSS score of 7.8, the issue has moderate‑to‑high severity, while an EPSS score of <1% indicates a low probability of exploitation. The flaw requires local kernel access or the ability to trigger a hotplug transition, making the primary attack vector local. It is not listed in CISA’s KEV catalog, and no publicly available exploits are known at this time. Silent masking of errors can lead to subtle stability or hardware availability problems.