CVE-2024-57935 is a vulnerability identified in the Linux kernel specifically affecting the RDMA (Remote Direct Memory Access) subsystem, particularly the hns (HiSilicon Network Subsystem) driver component. The issue arises during the destruction of a Queue Pair (QP), a fundamental RDMA communication endpoint. The vulnerability is caused by improper handling of the dip_ctx pointer, which is intended to be attached when a QP transitions to the Ready to Receive (RTR) state. If the QP fails to transition to RTR, the dip_ctx pointer remains unattached (invalid). However, during the destruction phase of the QP, the kernel attempts to access this invalid dip_ctx pointer, leading to a use-after-free or null pointer dereference scenario. This can cause kernel memory corruption, potentially leading to a denial of service (system crash) or other unpredictable kernel behavior. The vulnerability is rooted in a logic flaw in the state transition and resource cleanup code of the RDMA hns driver. The affected Linux kernel versions are identified by specific commit hashes, indicating that this is a recent issue fixed in the latest kernel updates. No known exploits are currently reported in the wild, and no CVSS score has been assigned yet. The vulnerability requires kernel-level access to trigger, and it does not appear to require user interaction beyond the ability to manipulate RDMA QPs, which typically implies privileged or specialized access. The flaw is significant in environments where RDMA is used, such as high-performance computing clusters, data centers, and enterprise servers relying on low-latency, high-throughput networking.

For European organizations, the impact of CVE-2024-57935 can be considerable in sectors that rely heavily on RDMA-enabled Linux servers, including telecommunications, cloud service providers, financial institutions, and research institutions with HPC infrastructure. Exploitation could lead to denial of service conditions, causing service outages and potential disruption of critical applications. While direct data exfiltration or privilege escalation is not explicitly indicated, kernel memory corruption can sometimes be leveraged for more severe attacks if combined with other vulnerabilities. The disruption of RDMA services can degrade performance and availability of latency-sensitive applications, impacting business continuity and operational efficiency. Organizations with Linux-based RDMA deployments must consider the risk of unpatched systems being targeted for disruption or as part of a multi-stage attack chain. Given the lack of known exploits, the immediate risk is moderate, but the potential for future exploitation exists once the vulnerability details become widely known.

To mitigate CVE-2024-57935, European organizations should promptly apply the latest Linux kernel patches that address this issue, ensuring that all RDMA-enabled systems are updated. Specifically, kernel versions containing the fix identified by the commit hashes in the advisory should be deployed. Organizations should audit their environments to identify systems using the hns RDMA driver and prioritize patching those systems. Additionally, restricting access to RDMA configuration interfaces to trusted administrators can reduce the risk of exploitation. Monitoring kernel logs for unusual RDMA-related errors or crashes can help detect attempts to exploit this vulnerability. Where feasible, temporarily disabling RDMA services on non-critical systems until patches are applied can reduce exposure. Network segmentation and strict access controls around RDMA-capable hosts can further limit attack surface. Finally, organizations should maintain an up-to-date inventory of Linux kernel versions in use and integrate this vulnerability into their patch management and vulnerability scanning processes to ensure timely remediation.