CVE-2021-47516 is a memory leak vulnerability identified in the Linux kernel's nfp (Netronome Flow Processor) driver, specifically within the function nfp_cpp_area_cache_add(). The vulnerability arises due to improper error handling when allocating a cache structure. In the vulnerable code, the function nfp_cpp_area_alloc() successfully allocates and initializes a CPP area structure. However, if the subsequent allocation of the cache structure (using kzalloc) fails, the previously allocated CPP area structure is not freed, resulting in a memory leak. This leak occurs because the code returns an error (-ENOMEM) without releasing the allocated memory, leading to gradual memory consumption over time if the failure condition is repeatedly triggered. The patch involves adding a free operation to release the CPP area structure when the cache allocation fails, thereby preventing the leak. While this vulnerability does not directly allow code execution or privilege escalation, memory leaks in kernel space can degrade system stability and performance, potentially leading to denial of service (DoS) conditions. The affected product is the Linux kernel, with specific affected versions identified by commit hashes. There are no known exploits in the wild, and no CVSS score has been assigned yet. The vulnerability is technical and low-level, impacting kernel memory management in the nfp driver component.

For European organizations, the primary impact of CVE-2021-47516 is related to system stability and availability. Organizations running Linux systems with the affected kernel versions and utilizing the nfp driver—commonly found in environments using Netronome network flow processors or similar hardware accelerators—may experience memory leaks that degrade performance or cause kernel instability over time. This can lead to unexpected system crashes or degraded network throughput, impacting critical infrastructure, data centers, or network appliances. While the vulnerability does not directly compromise confidentiality or integrity, the resulting denial of service could disrupt business operations, especially in sectors relying heavily on network performance such as telecommunications, cloud service providers, and financial services. Given the absence of known exploits, the immediate risk is moderate; however, unpatched systems could become targets for attackers aiming to cause disruption. European organizations with high network traffic and specialized hardware using the nfp driver are most at risk.

To mitigate CVE-2021-47516, organizations should: 1) Identify Linux systems running affected kernel versions and confirm whether the nfp driver is in use, particularly in network processing or acceleration roles. 2) Apply the official Linux kernel patches that fix the memory leak as soon as they are available and tested in the environment. 3) Monitor system logs and kernel memory usage for unusual increases that may indicate memory leaks. 4) Implement proactive kernel update policies to ensure timely patching of vulnerabilities. 5) For critical systems where immediate patching is not feasible, consider isolating affected hardware or limiting exposure to untrusted network traffic to reduce the chance of triggering the leak. 6) Engage with hardware vendors for firmware or driver updates that may also address this issue. 7) Conduct regular system health checks and stress tests to detect early signs of memory leaks or instability.