CVE-2025-37825 is a vulnerability identified in the Linux kernel's NVMe target (nvmet) subsystem, specifically in the function nvmet_enable_port. The issue arises when attempting to enable a port that has no transport configured. The function uses a constant NVMF_TRTYPE_MAX (value 255) as an index to query the transports array without verifying if the transport type is valid or configured. This leads to an out-of-bounds memory access, as the index 255 exceeds the bounds of the transports array. The kernel's Kernel Address Sanitizer (KASAN) detects this as a global out-of-bounds read, which can cause undefined behavior including kernel crashes (denial of service) or potential memory corruption. The root cause is that since commit 200adac75888, the default transport type for ports is set to NVMF_TRTYPE_MAX, which is not a valid transport type. The vulnerability can be mitigated by adding a check to ensure that the transport type is not NVMF_TRTYPE_MAX before proceeding with enabling the port. This flaw affects Linux kernel versions containing the specified commit and potentially others derived from it. No known exploits are reported in the wild as of now, and no CVSS score has been assigned. The vulnerability is technical and low-level, impacting kernel memory safety in a specific subsystem related to NVMe over Fabrics (NVMF) target ports.

For European organizations, the impact of CVE-2025-37825 depends largely on their use of Linux systems running vulnerable kernel versions with NVMe target functionality enabled. Organizations operating data centers, cloud infrastructure, or storage servers that utilize NVMe over Fabrics for high-performance storage networking are at risk. Exploitation could lead to kernel crashes causing denial of service, disrupting critical services and potentially leading to data unavailability. While direct privilege escalation or remote code execution is not explicitly indicated, memory corruption vulnerabilities in the kernel can sometimes be leveraged for more severe attacks if combined with other vulnerabilities. The lack of authentication or user interaction requirements suggests that local attackers or processes with the ability to trigger nvmet_enable_port could exploit this. Given the widespread use of Linux in European enterprise and public sector infrastructure, especially in cloud and storage environments, this vulnerability could affect availability and reliability of critical systems if unpatched. However, the absence of known exploits and the technical nature of the flaw reduce immediate risk. Organizations relying on NVMe target functionality should prioritize patching to prevent potential denial of service and maintain system stability.

1. Apply the official Linux kernel patches that fix the out-of-bounds access in nvmet_enable_port as soon as they are released. Monitor Linux kernel mailing lists and vendor advisories for updates. 2. Audit and restrict the use of NVMe target ports on Linux systems to only those necessary, minimizing the attack surface. 3. Implement kernel hardening and runtime protections such as Kernel Address Sanitizer (KASAN) in testing environments to detect similar memory safety issues early. 4. Monitor system logs for kernel warnings or crashes related to nvmet or transport type errors to detect potential exploitation attempts. 5. For environments where immediate patching is not feasible, consider disabling the NVMe target functionality if it is not required. 6. Ensure strict access controls and privilege separation to limit which users or processes can configure or enable NVMe target ports, reducing the risk of local exploitation. 7. Incorporate this vulnerability into vulnerability management and incident response plans to ensure timely detection and remediation.