CVE-2026-64477

/// Technical description

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

x86,fs/resctrl: Prevent out-of-bounds access while offlining CPU when SNC enabled

The architecture updates the cpu_mask in a domain's header to track which

online CPUs are associated with the domain. When this mask becomes empty

the architecture initiates offline of the domain that includes calling

on resctrl fs to offline the domain. If it is a monitoring domain in

which LLC occupancy is tracked resctrl fs forces the limbo handler to

clear all busy RMID state associated with the domain.

The limbo handler always reads the current event value associated with a

busy RMID irrespective of it being checked as part of regular "is it still

busy" check or whether it will be forced released anyway. When reading an

RMID on a system with SNC enabled the "logical RMID" is converted to the

"physical RMID" and this conversion requires the NUMA node ID of the

resctrl monitoring domain that is in turn determined by querying the NUM

/// 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.

/// References