CVE-2024-35908 is a vulnerability identified in the Linux kernel's TLS (Transport Layer Security) implementation, specifically within the function tls_sw_recvmsg. The issue arises from improper reference management of the 'psock' (presumably a pointer to a socket structure) during the receive message operation. Initially, the kernel code takes a reference on the psock before acquiring the rxlock (receive lock) via tls_rx_reader_lock. If the lock acquisition fails, the function returns immediately without releasing the previously taken reference, leading to a reference leak. This leak could cause resource exhaustion or memory management inconsistencies over time. The fix involves changing the code logic to take the psock reference only after successfully acquiring the rxlock, ensuring that no references are held if the lock is not obtained. This correction prevents the leak by aligning reference counting with lock acquisition, maintaining kernel stability and resource integrity. The vulnerability affects certain Linux kernel versions identified by specific commit hashes, and no known exploits are reported in the wild as of the publication date (May 19, 2024). No CVSS score has been assigned yet, and the vulnerability does not appear to be directly exploitable for privilege escalation or remote code execution but could degrade system reliability if left unpatched.

For European organizations relying on Linux-based systems, especially those using kernel versions affected by this vulnerability, the primary impact is on system stability and resource management. The reference leak could lead to gradual resource exhaustion, potentially causing degraded performance, denial of service, or kernel crashes in environments with high TLS traffic or heavy socket usage. This is particularly relevant for data centers, cloud providers, telecom operators, and enterprises running critical infrastructure on Linux servers. While the vulnerability does not directly compromise confidentiality or integrity, the availability of services could be impacted if the leak leads to system instability. Organizations with high uptime requirements or those operating in sectors such as finance, healthcare, or government services may experience operational disruptions if the vulnerability is exploited indirectly through resource depletion. Since no known exploits exist yet, the immediate risk is low, but the vulnerability should be addressed proactively to prevent future exploitation or accidental system failures.

European organizations should prioritize updating their Linux kernels to versions where this vulnerability is patched. Since the issue is related to kernel code, applying official Linux kernel updates or vendor-provided patches is the most effective mitigation. For environments where immediate patching is not feasible, monitoring system resource usage, particularly socket references and memory consumption related to TLS operations, can help detect abnormal behavior early. Implementing kernel hardening and resource limits may reduce the impact of potential leaks. Additionally, organizations should audit their TLS-dependent applications and services to ensure they handle socket connections efficiently and restart services periodically to clear leaked references if patching is delayed. Engaging with Linux distribution vendors for timely security updates and testing patches in staging environments before production deployment is recommended. Finally, maintaining comprehensive logging and alerting on kernel errors or unusual socket behavior can aid in early detection of issues stemming from this vulnerability.