Linux Kernel Cpufreq AMD Pstate Global Sysfs Attribute Type Confusion Vulnerability

A vulnerability in the Linux kernel's cpufreq AMD Pstate driver has been addressed. The issue arose when the 'amd_pstate' attributes were relocated from a dedicated kobject to the CPU root kobject. This change created a mismatch, as the dedicated kobject was designed for kobj_attributes, while the root kobject required device_attributes. Although this discrepancy was not frequently problematic, it triggered a Control Flow Integrity (CFI) failure, indicating a potential vulnerability.

Impact

The vulnerability could lead to a Control Flow Integrity failure, where the expected type of a device attribute was not met, potentially allowing for unintended behavior or exploitation.

Reproduction

The vulnerability can be reproduced by moving the 'amd_pstate' attributes from their dedicated kobject to the CPU root kobject, creating a mismatch between the expected and actual attribute types. This can be done by modifying the cpufreq AMD Pstate driver's handling of sysfs attributes to use the root kobject instead of a dedicated one.

Remediation

Users can upgrade to the latest version of the Linux kernel where this vulnerability has been fixed. The specific commit addressing this issue is available in the Linux kernel stable tree.