CVE-2024-57936 is a vulnerability identified in the Linux kernel's RDMA (Remote Direct Memory Access) subsystem, specifically affecting the bnxt_re driver which handles RDMA operations for Broadcom NetXtreme-E network adapters. The issue arises from a mismatch between the maximum number of Scatter-Gather Entries (SGEs) supported by the hardware and the software's internal data structures. The Gen P7 hardware supports up to 13 SGEs per Work Request, but the software structure for the Work Queue Element (WQE) currently only accommodates 6 SGEs. Because the maximum send SGE count is reported as 13, the system may accept Work Requests with up to 13 SGEs, which the software cannot properly handle. This discrepancy leads to traffic failures and can cause system crashes due to buffer overflows or memory corruption within the kernel's RDMA processing path. The fix involves updating the software to use a defined constant for the maximum SGEs supported, allowing the WQE structure to dynamically handle the correct number of SGEs, thus preventing the overflow and associated failures. This vulnerability is rooted in a low-level kernel driver and affects specific Linux kernel versions identified by their commit hashes. No known exploits are currently reported in the wild, and no CVSS score has been assigned yet.

For European organizations relying on Linux servers with RDMA-enabled Broadcom NetXtreme-E adapters, this vulnerability could lead to network traffic disruptions and system instability or crashes. RDMA is commonly used in high-performance computing, data centers, and enterprise environments to enable low-latency, high-throughput networking. A crash or traffic failure in such environments can cause significant downtime, impacting critical applications, data transfers, and services. Confidentiality and integrity impacts are less direct but could arise if system crashes lead to denial of service or if attackers leverage the instability to execute further attacks. The vulnerability requires no known authentication or user interaction, but exploitation depends on the presence of specific hardware and kernel versions. European organizations with data centers, research institutions, or enterprises using RDMA-enabled Linux servers are at risk of operational disruption until patched.

Organizations should immediately identify Linux systems running the affected kernel versions with Broadcom NetXtreme-E RDMA hardware. Applying the official Linux kernel patches that correct the max SGE handling is critical. Until patches are applied, administrators should consider disabling RDMA functionality on affected interfaces to prevent triggering the vulnerability, though this may impact performance. Monitoring system logs for RDMA-related errors or crashes can provide early warning signs. Network segmentation and limiting access to RDMA-enabled servers can reduce exposure. Additionally, organizations should maintain up-to-date inventories of hardware and kernel versions to quickly assess exposure to such vulnerabilities. Testing patches in staging environments before deployment is recommended to ensure stability.