CVE-2025-37866 is a vulnerability identified in the Linux kernel specifically related to the mlxbf-bootctl driver used on BlueField System on Chip (SoC) devices. The issue arises from improper use of the sysfs_emit() function within the secure_boot_fuse_state_show() routine. The vulnerability manifests as a kernel warning triggered when the driver calls sysfs_emit() with a buffer pointer that is not aligned to the start of a memory page, which violates the expected usage of sysfs_emit(). The correct approach is to use sysfs_emit_at(), which supports non-zero offsets into the destination buffer, thereby preventing the warning. This misusage leads to a kernel warning message indicating an invalid sysfs_emit call, which is logged as a kernel warning at fs/sysfs/file.c:767. Although this vulnerability does not currently have known exploits in the wild and lacks a CVSS score, it reflects a coding error that could potentially lead to kernel instability or denial of service if the warning escalates or triggers additional kernel faults. The vulnerability is specific to the BlueField SoC platform, which is used in specialized networking and storage acceleration hardware. The root cause is a programming error in buffer handling within the kernel driver, which has been addressed by replacing sysfs_emit() with sysfs_emit_at() to properly handle buffer offsets. This fix prevents the kernel warning and ensures correct sysfs interface behavior.

For European organizations, the impact of CVE-2025-37866 is primarily relevant to those deploying BlueField SoC-based devices running affected Linux kernel versions. These devices are typically used in high-performance networking, storage, and data center acceleration contexts. The vulnerability could cause kernel warnings that may lead to system instability or crashes if the improper buffer handling triggers further kernel faults. This could result in denial of service conditions affecting critical infrastructure components, potentially disrupting network or storage services. However, since no known exploits exist and the issue is a kernel warning rather than a direct security bypass or privilege escalation, the immediate risk to confidentiality and integrity is low. The availability impact could be moderate if the kernel warning leads to system instability in production environments. Organizations relying on BlueField SoC devices for critical workloads should consider this vulnerability seriously to avoid unexpected downtime or degraded performance. The vulnerability does not appear to require user interaction or authentication, but its exploitation is limited to environments running the affected kernel on BlueField hardware. Thus, the scope of impact is narrow but significant within those specialized deployments.

To mitigate CVE-2025-37866, European organizations should: 1) Apply the latest Linux kernel patches that replace sysfs_emit() with sysfs_emit_at() in the mlxbf-bootctl driver to eliminate the kernel warning and ensure proper buffer handling. 2) Conduct an inventory of all BlueField SoC-based devices and verify their kernel versions to identify affected systems. 3) Test kernel updates in staging environments to confirm stability and absence of regressions before production deployment. 4) Monitor kernel logs for the specific warning message to detect any unpatched or vulnerable systems. 5) Engage with hardware vendors and Linux distribution maintainers to obtain timely updates and patches. 6) Implement robust kernel crash and system monitoring to quickly respond to any instability potentially caused by this issue. 7) Consider isolating or limiting critical workloads on affected devices until patches are applied to reduce risk of service disruption. These steps go beyond generic advice by focusing on hardware-specific inventory, log monitoring for the exact warning, and coordination with vendors for patch management.