In the Linux kernel, a vulnerability has been identified and resolved that has potential implications for system stability. Specifically, this issue arises when loading the amd-pstate-ut driver, which can lead to kernel panic due to improper handling of CPU frequency policies. This vulnerability has been classified as medium severity, with a CVSS score of 5.5.
The risk to organizations includes system hang-ups that can affect availability and operational continuity. Attackers may leverage this vulnerability to create conditions that lead to prolonged system unresponsiveness, particularly when the amd_pstate mode is altered.
Organizations should prioritize patching immediately to mitigate the risk of being adversely affected by this vulnerability. As per the current exploitation status, there are no known public exploits or instances of active exploitation reported.
This vulnerability highlights the importance of proper resource management in system operations. The vulnerability was officially published on October 4, 2025, and it remains crucial for organizations to stay updated with security patches.
Vulnerability Details
The vulnerability is described as follows: after loading the amd-pstate-ut driver, the functions amd_pstate_ut_check_perf() and amd_pstate_ut_check_freq() utilize cpufreq_cpu_get() to obtain the CPU policy and mark it as busy. However, cpufreq_cpu_put() is not called to release the policy, which results in any other entity attempting to access the policy being blocked indefinitely.
The CVSS score of 5.5 indicates that the vulnerability has a medium impact, with a high availability impact. It requires low privileges and low complexity to exploit, making it a relevant concern for system administrators.
The vulnerability affects the Linux kernel versions from 6.1 up to but not including 6.1.53, as well as versions starting from 6.2 to below 6.4.16, and from 6.5 to below 6.5.3.
Technical Analysis
The root cause of this vulnerability is the failure to properly release CPU frequency policies after being accessed. When the amd_pstate mode is altered, it leads to a kernel panic as observed in the logs, which indicate that tasks can be blocked indefinitely.
The attack vector for this vulnerability is local, as it requires access to the system to manipulate CPU settings. The attack complexity is low, with privileges required being low, meaning that an attacker with standard user access could potentially exploit this.
No user interaction is required to exploit this vulnerability, and the confidentiality and integrity impacts are none, while the availability impact is high.
Risk & Impact Analysis
The real-world deployment risk associated with this vulnerability is significant, especially for organizations relying on the Linux kernel for critical operations. With the potential for system hang-ups, the operational impact could cause disruptions and affect user productivity.
Given the current CVSS score, organizations should address this vulnerability in their priority patch cycle. The blast radius could be extensive depending on the scale of the deployment of affected kernel versions.
Organizations should also monitor for any changes in the exploitability of this vulnerability, as this could evolve over time. The fact that it has not been included in the KEV catalog suggests that it is not currently being exploited in the wild, which provides a temporary buffer for remediation efforts.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The affected versions of the Linux kernel include:
1. All versions from 6.1 up to but not including 6.1.53 2. All versions from 6.2 up to but not including 6.4.16 3. All versions from 6.5 up to but not including 6.5.3
Mitigation & Remediation
To mitigate this vulnerability, organizations should implement the following actions:
1. Apply the latest patches for the Linux kernel as they become available. 2. Monitor kernel updates and apply them in a timely manner. 3. If a patch is not yet available, consider implementing configuration hardening strategies to limit exposure.
Organizations should validate remediation through continuous penetration testing to identify similar weaknesses.
Detection Guidance
Organizations should monitor for the following indicators to detect any exploitation of this vulnerability:
1. Logs indicating long wait times for CPU resource allocation. 2. Behavioral anomalies in system performance, such as unexpected hangs or slowdowns. 3. Network signatures associated with system resource manipulation.
AppSecure Threat Intelligence Insight
This vulnerability emphasizes the critical need for organizations to ensure robust kernel management practices. The pattern of resource management failures can lead to significant operational disruptions. Security teams should take away the importance of proactive monitoring and the necessity of timely patching to prevent potential exploitation.
For further reading on security best practices, organizations can refer to the following resources:
Vulnerability management program design and penetration testing methodology to strengthen overall security posture.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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