CVE-2021-47042 is a vulnerability identified in the Linux kernel, specifically within the AMD GPU driver subsystem (amdgpu) related to the Direct Rendering Manager (DRM) component. The issue involves a memory leak in the function dc_link_construct(), which is part of the display core (dc) initialization process for AMD GPUs. The vulnerability arises because local data allocated during the link creation process is not properly freed after use, leading to unreferenced objects consuming kernel memory. The backtrace provided indicates that the leak occurs during the allocation and initialization of display link structures when the AMD GPU driver loads and initializes the device. Although this is a memory leak rather than a direct code execution or privilege escalation flaw, it can degrade system performance or stability over time, especially on systems with AMD GPUs running affected Linux kernel versions. The vulnerability has been fixed by ensuring that the allocated local data is freed appropriately after use, preventing the accumulation of leaked memory. No known exploits are reported in the wild, and no CVSS score has been assigned yet. The affected versions are identified by specific kernel commit hashes, indicating that this is a relatively recent fix in the Linux kernel source.

For European organizations, the impact of CVE-2021-47042 is primarily related to system stability and resource exhaustion rather than immediate security breaches such as data theft or system takeover. Organizations using Linux systems with AMD GPUs, particularly in environments where uptime and performance are critical (e.g., data centers, cloud providers, research institutions, and enterprises relying on GPU-accelerated workloads), may experience degraded performance or potential system instability if the memory leak accumulates over time. This could lead to increased maintenance costs, unexpected reboots, or degraded user experience. While the vulnerability does not directly compromise confidentiality or integrity, prolonged exploitation could indirectly affect availability, which is a key concern for critical infrastructure and service providers in Europe. Since no active exploits are known, the immediate risk is low, but unpatched systems remain vulnerable to potential future exploitation or operational issues.

To mitigate this vulnerability, European organizations should prioritize updating their Linux kernel to the latest stable version that includes the fix for CVE-2021-47042. Specifically, kernel versions incorporating the patch that frees local data after use in the dc_link_construct() function should be deployed. System administrators should audit their environments to identify Linux hosts running AMD GPU drivers and verify kernel versions. For environments where kernel upgrades are challenging, consider applying backported patches if available from Linux distribution maintainers. Additionally, monitoring system memory usage patterns on affected hosts can help detect abnormal memory consumption indicative of the leak. Implementing proactive system restarts or resource management policies may temporarily alleviate symptoms until patches are applied. Finally, maintaining robust patch management processes and subscribing to Linux kernel security advisories will ensure timely awareness and response to similar vulnerabilities.