CVE-2021-47532 is a vulnerability identified in the Linux kernel, specifically within the Direct Rendering Manager (DRM) subsystem for Qualcomm MSM (Mobile Station Modem) devices, related to the devfreq (device frequency scaling) component. The issue involves a leak of the Operating Performance Points (OPP) reference count, which is a mechanism used to manage and track the power and frequency states of hardware components. The OPP refcount leak means that the kernel fails to properly decrement reference counts when they are no longer needed, potentially leading to resource exhaustion or inconsistent power management states. This flaw could cause degraded system performance or instability, as the device frequency scaling might not function correctly, potentially impacting power consumption and thermal management. Although no known exploits are reported in the wild, the vulnerability affects Linux kernel versions containing the specified commit hashes, which are likely part of the kernel branches used in embedded or mobile devices running Qualcomm MSM chipsets. The vulnerability was reserved and published in May 2024, and no CVSS score has been assigned yet. The fix involves correcting the reference count handling in the drm/msm/devfreq code to prevent the leak and ensure proper resource management.

For European organizations, the impact of CVE-2021-47532 primarily concerns devices and systems running Linux kernels with Qualcomm MSM chipsets, commonly found in embedded systems, mobile devices, and potentially IoT devices. The vulnerability could lead to degraded device performance, increased power consumption, or system instability, which may affect operational continuity, especially in critical infrastructure or industrial environments relying on embedded Linux systems. While it does not directly enable remote code execution or privilege escalation, the resource leak could be exploited in a denial-of-service scenario by exhausting kernel resources, leading to system crashes or degraded service availability. Organizations in sectors such as telecommunications, manufacturing, automotive, and critical infrastructure that deploy Linux-based embedded devices should be particularly vigilant. The absence of known exploits reduces immediate risk, but unpatched systems remain vulnerable to potential future exploitation or cascading failures due to resource mismanagement.

To mitigate CVE-2021-47532, European organizations should: 1) Identify and inventory all Linux systems using Qualcomm MSM chipsets or affected kernel versions, including embedded and IoT devices. 2) Apply the official Linux kernel patches or updates that fix the OPP refcount leak as soon as they become available from trusted sources or vendor distributions. 3) For devices where kernel updates are not feasible, consider implementing monitoring for abnormal system behavior such as increased power consumption, thermal events, or unexpected reboots that could indicate resource leaks. 4) Engage with device vendors to confirm patch availability and deployment timelines. 5) Incorporate this vulnerability into vulnerability management and incident response plans to ensure rapid detection and remediation. 6) Limit exposure by segmenting affected devices on the network and restricting access to trusted users and systems to reduce the risk of exploitation or cascading failures.