CVE-2024-53140 addresses a vulnerability in the Linux kernel's netlink subsystem, specifically related to the handling of iterative data dumps over netlink sockets. Netlink sockets facilitate communication between kernel and user space, often used for networking configuration and monitoring. The netlink interface supports an asynchronous iterative dumping mechanism where data is sent in chunks via repeated calls to a dump helper function until completion. This process involves optional start and done callbacks to manage the lifecycle of the dump operation. The vulnerability arises from improper cleanup when a netlink socket is closed before the dump completes. The kernel attempts to pair the start and done callbacks to ensure proper cleanup. However, the existing implementation defers cleanup work to a workqueue to avoid sleeping in bottom halves (BH), but mistakenly defers the release of the socket reference rather than the actual cleanup. This can lead to race conditions where socket references are released prematurely or incorrectly, potentially causing use-after-free scenarios or inconsistent kernel state. The root cause is that socket freeing can occur asynchronously in BH context, while the done callback is allowed to sleep, leading to an unsafe cleanup sequence. The fix removes the unnecessary workqueue and instead performs synchronous cleanup directly in the socket release handler, ensuring that the done callback is always called before the socket is fully released. This change simplifies the cleanup logic and eliminates the race condition. Although no known exploits are reported in the wild, the vulnerability could theoretically be triggered by a local user or process interacting with netlink sockets, potentially leading to kernel memory corruption or stability issues. The affected versions include multiple Linux kernel commits identified by their hashes, indicating that this is a recent and specific patch to the kernel source code. No CVSS score is assigned yet, and no public exploit code is known.

For European organizations, the impact of this vulnerability depends largely on their use of Linux-based systems, particularly those that rely on netlink sockets for networking management, monitoring, or other kernel-user space communication. Since Linux is widely deployed across servers, cloud infrastructure, embedded devices, and network appliances, this vulnerability could affect a broad range of systems. Potential impacts include kernel crashes, denial of service, or in worst cases, privilege escalation or arbitrary code execution if an attacker can exploit the race condition to corrupt kernel memory. This could disrupt critical services, especially in sectors relying heavily on Linux infrastructure such as telecommunications, finance, government, and cloud service providers. The asynchronous nature of the bug and its relation to socket closure means that exploitation would require local access or a compromised process capable of interacting with netlink sockets. While remote exploitation is unlikely without prior access, insider threats or compromised containers/VMs could leverage this vulnerability to escalate privileges or destabilize systems. Given the kernel-level nature, successful exploitation could undermine system integrity and availability, impacting compliance with European data protection regulations and operational continuity.

European organizations should prioritize updating their Linux kernels to versions that include the patch for CVE-2024-53140 as soon as they become available from their Linux distribution vendors. Since this is a kernel-level fix, applying official kernel updates is the most effective mitigation. Additionally, organizations should: 1) Restrict local user access to systems and limit permissions to interact with netlink sockets to trusted processes only. 2) Employ kernel hardening techniques such as SELinux or AppArmor policies to constrain processes that can open or manipulate netlink sockets. 3) Monitor system logs and kernel messages for unusual netlink socket activity or crashes that could indicate exploitation attempts. 4) Use container and VM isolation best practices to prevent lateral movement and privilege escalation from compromised environments. 5) Engage in proactive vulnerability management to track Linux kernel updates and apply patches promptly. 6) For critical infrastructure, consider deploying kernel live patching solutions to minimize downtime while applying fixes. These steps go beyond generic advice by focusing on controlling access to netlink interfaces and monitoring for exploitation signs specific to this vulnerability.