CVE-2025-37920 is a vulnerability identified in the Linux kernel's AF_XDP (Address Family eXpress Data Path) generic RX (receive) path. AF_XDP is a high-performance packet processing interface designed to enable fast packet processing in user space by bypassing the kernel network stack. The vulnerability arises from a race condition due to improper synchronization in the handling of RX and FILL queues when multiple sockets share a single xsk_buff_pool in shared umem (user memory) mode. Specifically, the RX queue is exclusive to each xsk_socket, while the FILL queue can be shared among multiple sockets. The race condition occurs when two CPU cores concurrently access the RX path of different sockets sharing the same umem, potentially leading to data corruption or inconsistent state. The fix involves moving the rx_lock spinlock from the xsk_socket structure to the shared xsk_buff_pool and protecting both RX and FILL queues by acquiring this spinlock, ensuring proper synchronization. The patch also reorders the spin_lock_bh(rx_lock) to occur after xsk_rcv_check(), which is safe due to memory barriers and synchronization mechanisms in place during socket binding and unbinding. This vulnerability does not require user interaction and can be triggered in environments where multiple AF_XDP sockets share umem, which is common in high-performance networking applications. No known exploits are currently reported in the wild, and no CVSS score has been assigned yet.

For European organizations, the impact of this vulnerability can be significant, particularly for enterprises and service providers relying on Linux-based high-performance networking solutions, such as telecom operators, cloud providers, and data centers. Exploitation of this race condition could lead to data corruption, packet loss, or denial of service in critical network functions, affecting the availability and integrity of network communications. This could disrupt services dependent on real-time packet processing, including 5G infrastructure, financial trading platforms, and industrial control systems. Although no direct confidentiality breach is indicated, the instability caused by the race condition could indirectly affect data integrity and system reliability. Organizations using custom or commercial solutions leveraging AF_XDP for accelerated packet processing are at higher risk. Given the Linux kernel's widespread use across European IT infrastructure, the vulnerability has broad potential impact if left unpatched.

Organizations should prioritize updating their Linux kernel versions to include the patch that addresses CVE-2025-37920. Since the vulnerability involves kernel-level synchronization, applying vendor-provided kernel updates or recompiling kernels with the fix is essential. For environments using AF_XDP sockets with shared umem, administrators should audit their configurations to identify shared xsk_buff_pool usage and consider isolating sockets where feasible to reduce risk exposure. Monitoring kernel logs and network performance metrics for anomalies related to packet processing can help detect exploitation attempts or instability. Additionally, organizations should implement strict change management and testing procedures when deploying kernel updates to avoid service disruptions. Network segmentation and limiting access to systems performing high-performance packet processing can further reduce attack surface. Finally, staying informed through Linux kernel mailing lists and security advisories will ensure timely awareness of any emerging exploits or patches.