CVE-2025-37933 is a vulnerability identified in the Linux kernel's octeon_ep network driver. The issue arises during device reboot scenarios when the host system loses heartbeat messages from the device. In this situation, the driver calls the device-specific ndo_stop function to free resources. However, if the driver is subsequently unloaded while the device is already stopped, ndo_stop is called again, leading to a double-free of resources. This double-free condition causes the host system to hang, effectively resulting in a denial-of-service (DoS) condition. The root cause is that the driver incorrectly calls ndo_stop directly during unload instead of using dev_close, which internally manages the stopping of the network interface and performs necessary cleanup, including preventing double-free errors. The fix involves replacing the direct call to ndo_stop with dev_close during driver unload, ensuring that if the device is already down, ndo_stop is not called again. This vulnerability specifically affects the octeon_ep driver within the Linux kernel, which is used for networking on certain Cavium Octeon processors. There are no known exploits in the wild at the time of publication, and no CVSS score has been assigned yet. The vulnerability was published on May 20, 2025, and the affected Linux kernel versions are identified by specific commit hashes. The issue primarily impacts system stability by causing host hangs during device reboot or driver unload operations involving the octeon_ep driver.

For European organizations, the primary impact of CVE-2025-37933 is the potential for system instability and denial-of-service conditions on Linux systems using the octeon_ep driver. This can disrupt critical network services, especially in environments relying on Cavium Octeon-based hardware for networking tasks, such as telecommunications infrastructure, data centers, and enterprise networking equipment. A host hang can lead to downtime, loss of productivity, and potential cascading failures in network-dependent operations. While this vulnerability does not directly expose data confidentiality or integrity, the availability impact can be significant for organizations with high uptime requirements. In sectors such as finance, healthcare, and critical infrastructure within Europe, even short outages can have regulatory and operational consequences. The lack of known exploits reduces immediate risk, but the vulnerability should be addressed proactively to prevent potential exploitation or accidental system hangs during maintenance or device reboots.

European organizations should take the following specific mitigation steps: 1) Identify Linux systems running kernels with the octeon_ep driver, particularly those using Cavium Octeon processors. 2) Apply the official Linux kernel patches that replace the direct ndo_stop calls with dev_close during driver unload to prevent double-free and host hang conditions. 3) Test patches in staging environments to ensure stability before deployment in production, especially in critical network infrastructure. 4) Implement monitoring for host hangs or network interface failures that could indicate attempts to trigger this vulnerability. 5) Establish maintenance procedures that avoid unloading the octeon_ep driver during active device heartbeat loss scenarios until patched. 6) Coordinate with hardware vendors and Linux distribution maintainers to ensure timely updates and backports for affected kernel versions. 7) Educate system administrators about the symptoms and safe handling of device reboots involving the octeon_ep driver to minimize accidental hangs.