CVE-2021-47067 is a vulnerability identified in the Linux kernel specifically within the Tegra subsystem's regulator driver code. The issue arises from improper handling of voltage spread parameters in the voltage coupler logic. When the voltage-spread value is out of the expected range, a locking condition occurs, causing the regulator to lock up. This bug is related to the max-spread requirement not being properly enforced when the CPU regulator has no consumers. The problem was notably observed on the Tegra30-based Ouya game console when system-wide Dynamic Voltage and Frequency Scaling (DVFS) is enabled via device-tree configuration. The lockup can cause the regulator to become unresponsive, potentially leading to system instability or denial of service conditions. The vulnerability is rooted in a logic flaw in the kernel's power management code for Tegra SoCs, which are commonly used in embedded devices and some specialized hardware platforms. The fix involves correcting the locking mechanism and ensuring the voltage spread constraints are properly checked and enforced, preventing the lockup scenario. There is no indication that this vulnerability has been exploited in the wild, and no CVSS score has been assigned yet.

For European organizations, the impact of CVE-2021-47067 depends largely on the use of Tegra-based Linux systems within their infrastructure. While Tegra SoCs are primarily found in embedded and specialized devices rather than mainstream servers or desktops, organizations relying on such hardware for industrial control, IoT deployments, or specialized computing tasks could face system instability or denial of service if the vulnerability is triggered. This could disrupt critical operations, especially in sectors like manufacturing, automotive, or telecommunications where embedded Linux devices are prevalent. The lockup could cause downtime or require manual intervention to recover devices, impacting availability. Confidentiality and integrity impacts appear minimal as the vulnerability is related to power management lockup rather than code execution or privilege escalation. However, availability degradation in critical embedded systems can have cascading effects on operational continuity and safety.

To mitigate this vulnerability, organizations should ensure that all Tegra-based Linux kernel deployments are updated to the latest patched kernel versions that include the fix for CVE-2021-47067. Specifically, kernel maintainers and device vendors should apply the patch that corrects the voltage spread locking logic. For embedded device operators, it is critical to verify device-tree configurations related to DVFS and voltage regulators to avoid enabling configurations that could trigger the bug. Monitoring device logs for regulator lockup symptoms and implementing automated recovery mechanisms (such as watchdog timers or remote reboot capabilities) can reduce operational impact. Additionally, organizations should maintain an inventory of Tegra-based devices to assess exposure and prioritize patching. Since no known exploits exist in the wild, proactive patching and configuration review remain the best defense.