CVE-2024-35834 is a vulnerability identified in the Linux kernel, specifically related to the AF_XDP socket (xsk) implementation. AF_XDP is a high-performance packet processing interface that allows user-space applications to directly access network packets, bypassing much of the kernel networking stack for efficiency. The vulnerability arises from a missing call to xsk_buff_free() in the __xsk_rcv_zc() function when it fails to produce a descriptor to the XSK receive (Rx) queue. This omission leads to a recycle buffer not being freed properly in cases where the Rx queue is full. Essentially, when the Rx queue cannot accept new descriptors due to being full, the buffer that should have been recycled and freed remains allocated, potentially causing a memory leak or buffer exhaustion. Over time, this could degrade system performance or lead to denial of service (DoS) conditions. The vulnerability does not appear to have any known exploits in the wild as of the published date (May 17, 2024), and no CVSS score has been assigned yet. The affected versions are identified by a specific commit hash, indicating that this issue is relevant to recent Linux kernel versions incorporating the AF_XDP functionality. The patch involves adding the missing xsk_buff_free() call to ensure proper buffer recycling when the Rx queue is full, preventing resource leakage. This vulnerability is technical and low-level, affecting kernel network buffer management in a specialized subsystem used primarily in high-performance networking scenarios.

For European organizations, the impact of CVE-2024-35834 depends largely on their deployment of Linux systems utilizing AF_XDP sockets, which are typically found in environments requiring high-speed packet processing such as telecommunications infrastructure, cloud service providers, data centers, and network appliance vendors. If exploited or left unpatched, the vulnerability could lead to resource exhaustion on critical network servers or appliances, resulting in degraded network performance or denial of service. This could disrupt business operations, especially for sectors relying on real-time data processing or high availability, such as financial services, telecommunications, and critical infrastructure. While the vulnerability does not directly expose confidentiality or integrity risks, the availability impact could be significant in environments with heavy network traffic. The lack of known exploits reduces immediate risk, but the potential for DoS conditions means that organizations should prioritize patching to maintain network reliability and service continuity.

1. Immediate application of the official Linux kernel patch that adds the missing xsk_buff_free() call in the __xsk_rcv_zc() function to ensure proper buffer recycling. 2. For organizations unable to patch immediately, monitor network devices and servers using AF_XDP for abnormal memory usage or performance degradation indicative of buffer leaks. 3. Limit exposure by restricting access to systems running vulnerable kernel versions to trusted networks and users only. 4. Employ kernel-level monitoring tools to detect unusual socket buffer states or queue fullness that could signal exploitation attempts or resource exhaustion. 5. Engage with Linux distribution vendors to obtain updated kernel packages and verify that all network-facing systems are updated promptly. 6. Review and test network applications using AF_XDP sockets to ensure they handle queue full conditions gracefully and do not exacerbate resource exhaustion.