CVE-2021-47513 is a vulnerability identified in the Linux kernel specifically within the Distributed Switch Architecture (DSA) subsystem, related to the Felix driver. The issue involves a memory leak occurring in the felix_setup_mmio_filtering function when no CPU port is defined. This memory leak results from resources not being properly released during the setup process of memory-mapped I/O filtering in the network driver. The vulnerability was detected and addressed by fixing the resource management to avoid leaking memory under these specific conditions. Although the vulnerability does not directly allow code execution or privilege escalation, the leak could lead to gradual resource exhaustion on affected systems, potentially degrading system performance or causing denial of service over time. The affected versions correspond to specific Linux kernel commits prior to the fix, indicating that systems running these kernel versions or derivatives thereof are vulnerable. There are no known exploits in the wild at this time, and no CVSS score has been assigned. The vulnerability was identified through static analysis tools (Coverity) and fixed in the Linux kernel source. This issue is primarily relevant to environments using the Felix DSA driver, which is typically deployed in embedded or specialized network hardware running Linux.

For European organizations, the impact of CVE-2021-47513 depends largely on their use of Linux systems with the Felix DSA driver enabled. Organizations operating network infrastructure, telecommunications equipment, or embedded devices that utilize this driver could experience memory leaks leading to resource exhaustion. Over time, this could degrade network device performance or cause unexpected reboots or failures, impacting availability of critical network services. While the vulnerability does not appear to allow direct compromise of confidentiality or integrity, the availability impact could disrupt business operations, especially in sectors relying on stable network infrastructure such as finance, manufacturing, and critical infrastructure. The absence of known exploits reduces immediate risk, but unpatched systems remain vulnerable to potential future exploitation or accidental denial of service. European organizations with large-scale Linux deployments in network equipment should prioritize patching to maintain operational stability and avoid service interruptions.

To mitigate CVE-2021-47513, organizations should: 1) Identify Linux systems running kernel versions containing the vulnerable Felix DSA driver code, particularly those using embedded or specialized network hardware. 2) Apply the official Linux kernel patches that fix the memory leak as soon as possible. If immediate patching is not feasible, consider disabling the Felix DSA driver or the MMIO filtering feature if it is not required for operational purposes. 3) Monitor system memory usage and network device logs for signs of resource exhaustion or instability that could indicate the leak is impacting operations. 4) Incorporate this vulnerability into vulnerability management and patching workflows to ensure timely updates. 5) Engage with hardware vendors to confirm firmware or driver updates are available and deployed for affected network devices. 6) For critical infrastructure, implement redundancy and failover mechanisms to mitigate potential availability impacts from device failures related to this vulnerability.