In the Linux kernel, the following vulnerability has been resolved: rcu: Fix __this_cpu_read() lockdep warning in rcu_force_quiescent_state(). Running rcutorture with non-zero fqs_duration module parameter in a kernel built with CONFIG_PREEMPTION=y results in the following splat: BUG: using __this_cpu_read() in preemptible code: rcu_torture_fqs/398. The caller is __this_cpu_preempt_check. The problem is that rcu_force_quiescent_state() uses __this_cpu_read() in preemptible code instead of the proper raw_cpu_read(). This commit changes __this_cpu_read() to raw_cpu_read().
This vulnerability allows potential disruption in kernel operations, which could lead to performance degradation under specific conditions. Even though the status is deferred, it is essential for organizations to understand the implications of such vulnerabilities.
The risk to organizations includes possible operational interruptions or performance issues in applications relying on the Linux kernel. Although there is currently no known exploit associated with this vulnerability, organizations should maintain awareness of future developments.
Urgency for defenders is currently low, as the vulnerability is classified as deferred. However, continuous monitoring for updates related to this CVE is recommended.
Vulnerability Details
CVE-2022-50771 is identified as an issue in the Linux kernel, specifically concerning the improper use of __this_cpu_read() in a preemptible context. The vulnerability was published on December 24, 2025, with a deferred status indicating that further investigation or action may be pending.
The CVSS score for this vulnerability has not been officially assigned, indicating a lack of severity classification at this time. The CWE classification is also not applicable as no specific weaknesses are detailed.
Technical Analysis
The root cause stems from the usage of __this_cpu_read() where raw_cpu_read() should have been employed. This oversight can lead to operational issues during the execution of the kernel, particularly under the conditions specified in the rcutorture test.
The attack vector for this vulnerability is classified as unknown, indicating that the specific method of exploitation has not been detailed. Given the nature of this issue, it is likely that the complexity of an attack remains high, as it would require specific conditions to trigger.
There are no privileges required to exploit this vulnerability, nor is any user interaction necessary. The impact on confidentiality, integrity, and availability remains undetermined at this time.
Risk & Impact Analysis
The risk to organizations includes potential disruptions in kernel operations which can lead to performance drops under specific test conditions. Although the vulnerability is currently marked as deferred, organizations should be aware that changes in its status could elevate its risk profile.
Understanding the significance of this vulnerability is crucial, especially for organizations utilizing Linux in critical operations. The blast radius potential may vary, but the implications of kernel vulnerabilities can be far-reaching.
Organizations should continuously assess their deployment of affected kernel versions and remain alert for any updates regarding this or related vulnerabilities.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
All versions prior to vendor patch.
Mitigation & Remediation
Organizations should remain aware of updates related to this vulnerability. While the status is currently deferred, monitoring for future patches is advised. Regularly updating the Linux kernel can mitigate potential risks from similar vulnerabilities.
Detection Guidance
Monitoring kernel logs for anomalies or unusual behavior can help detect potential exploitation attempts, although no active exploits have been reported.
AppSecure Threat Intelligence Insight
The long-term significance of this vulnerability in the Linux kernel highlights the ongoing need for vigilance in kernel security. Organizations should learn from this incident to strengthen their security posture against similar vulnerabilities.
For further insights into vulnerability management, security teams can refer to our resources on the vulnerability management program and effective penetration testing methodology strategies to mitigate risks.
Security teams should also focus on maintaining updated knowledge of kernel vulnerabilities through continuous education and engagement with relevant resources.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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