CVE-2021-47287 is a vulnerability identified in the Linux kernel's driver core, specifically within the auxiliary bus subsystem. The issue arises when the function driver_register() fails during the registration of an auxiliary driver. In such failure scenarios, the kernel code does not properly free the memory allocated for the driver's name (auxdrv->driver.name) before returning from the __auxiliary_driver_register() function. This results in a memory leak within the kernel space. Although a memory leak does not directly allow code execution or privilege escalation, it can degrade system stability and performance over time, especially on systems that frequently load and unload drivers or auxiliary devices. The vulnerability is present in certain Linux kernel versions identified by the commit hash 7de3697e9cbd4bd3d62bafa249d57990e1b8f294. The issue has been addressed by ensuring that the allocated memory is freed appropriately when driver_register() returns an error. No known exploits are currently reported in the wild, and no CVSS score has been assigned to this vulnerability yet.

For European organizations, the impact of CVE-2021-47287 is primarily related to system reliability and resource management rather than direct security compromise. Systems running affected Linux kernel versions that utilize auxiliary drivers could experience gradual memory exhaustion due to leaks, potentially leading to degraded performance, system instability, or crashes. This can affect critical infrastructure, servers, and embedded devices relying on Linux, especially in environments with high driver churn or dynamic hardware configurations. While this vulnerability does not directly expose confidential data or allow unauthorized access, the resulting instability could disrupt business operations, cause downtime, and increase maintenance costs. Organizations with stringent uptime requirements, such as financial institutions, healthcare providers, and industrial control systems in Europe, may find this vulnerability more impactful. However, the absence of known exploits and the nature of the flaw suggest a lower immediate risk of targeted attacks.

To mitigate CVE-2021-47287, European organizations should prioritize updating their Linux kernel to the patched versions where the memory leak has been fixed. Kernel updates should be tested and deployed promptly, especially on systems that frequently register and unregister auxiliary drivers. System administrators should monitor kernel logs for driver registration errors and memory usage patterns to detect potential leaks early. For environments where immediate patching is not feasible, implementing strict resource monitoring and automated alerts for abnormal memory consumption can help mitigate impact. Additionally, organizations should review their driver management policies to minimize unnecessary driver registrations and removals, reducing exposure to this issue. Employing containerization or virtualization to isolate critical workloads can also limit the impact of potential kernel instability caused by this vulnerability.