CVE-2021-47422 is a vulnerability identified in the Linux kernel, specifically within the Direct Rendering Manager (DRM) subsystem's nouveau driver component, which handles NVIDIA graphics hardware (nv50 series). The issue arises from improper resource management in the kernel code where the function single_open() is used to open a file, but the corresponding single_release() function is not called upon file release. This omission causes a memory leak because the 'op' structure allocated by single_open() remains unreleased. While this vulnerability does not directly allow code execution or privilege escalation, the memory leak can degrade system stability and performance over time, especially on systems with heavy graphics usage or prolonged uptime. The leak occurs in kernel space, which means it could potentially be exploited to cause denial of service (DoS) conditions by exhausting kernel memory resources. The vulnerability has been resolved by ensuring that single_release() is properly called to free the allocated memory. No known exploits are currently reported in the wild, and no CVSS score has been assigned yet.

For European organizations, the impact of CVE-2021-47422 primarily concerns system reliability and availability rather than direct compromise of confidentiality or integrity. Organizations relying on Linux servers or workstations with NVIDIA graphics hardware using the nouveau driver could experience gradual memory exhaustion leading to system instability or crashes. This is particularly relevant for sectors with high graphical processing demands such as media production, scientific computing, and certain industrial control systems. Additionally, embedded systems or network appliances running affected Linux kernels could face degraded performance or unexpected reboots, potentially disrupting critical services. Although the vulnerability does not currently have known exploits, the risk of denial of service through resource exhaustion could impact operational continuity if left unpatched.

To mitigate this vulnerability, European organizations should: 1) Apply the latest Linux kernel updates that include the patch fixing the memory leak in the nouveau driver. 2) Monitor system logs and kernel memory usage for unusual patterns that might indicate resource leaks. 3) For systems where kernel updates are delayed, consider disabling the nouveau driver if NVIDIA proprietary drivers are an option and compatible, as this can reduce exposure. 4) Implement proactive system resource monitoring and automated alerts to detect early signs of memory leaks or system instability. 5) In environments with critical uptime requirements, schedule regular reboots as a temporary measure to clear leaked memory until patches are applied. 6) Engage with Linux distribution vendors for timely security updates and verify that custom kernels incorporate the fix.