CVE-2025-37802 is a vulnerability identified in the Linux kernel, specifically within the ksmbd (Kernel SMB Daemon) component. The issue arises from improper handling of task states during mutex locking operations in the function ksmbd_durable_scavenger_alive(). The vulnerability is triggered because wait_event_timeout() sets the current task's state to TASK_UNINTERRUPTIBLE before checking the condition. Consequently, ksmbd_durable_scavenger_alive() attempts to acquire a mutex lock while the task is already in a sleeping state, which violates kernel scheduling rules and triggers a warning: "do not call blocking ops when !TASK_RUNNING". This improper locking can lead to kernel warnings and potentially unstable behavior or deadlocks within the ksmbd service. The root cause is that the mutex lock in ksmbd_durable_scavenger_alive() is unnecessary and should be removed to prevent blocking operations during non-runnable task states. Although no known exploits are currently reported in the wild, the vulnerability could cause system instability or denial of service (DoS) conditions if triggered. The vulnerability affects specific Linux kernel versions identified by commit hashes, indicating it is present in recent kernel builds prior to the patch. No CVSS score has been assigned yet, and no public patch links are provided in the data, but the issue is acknowledged and published as of May 2025.

For European organizations, the impact of CVE-2025-37802 primarily concerns systems running Linux kernels with the vulnerable ksmbd implementation, especially those utilizing SMB services for file sharing and network resource access. The vulnerability could lead to kernel warnings, potential deadlocks, or crashes in the ksmbd service, resulting in denial of service for SMB clients. This can disrupt critical file sharing and collaboration services, impacting business continuity, especially in sectors relying heavily on Linux-based infrastructure such as finance, telecommunications, and public administration. While the vulnerability does not appear to allow privilege escalation or remote code execution directly, the resulting instability could be exploited as part of a broader attack chain or cause operational disruptions. Given the widespread use of Linux in European data centers, cloud environments, and enterprise servers, unpatched systems may face increased risk of service outages. Additionally, organizations with strict uptime and availability requirements could experience reputational and financial damage if SMB services are interrupted. The lack of known exploits reduces immediate risk, but the vulnerability's presence in kernel-level code warrants prompt attention to avoid potential exploitation or accidental system failures.

European organizations should prioritize updating their Linux kernels to versions where this vulnerability is resolved. Since the root cause is the unnecessary mutex lock in ksmbd_durable_scavenger_alive(), applying the official kernel patch that removes this locking behavior is essential. Organizations should: 1) Identify all Linux systems running vulnerable kernel versions, focusing on those providing SMB services via ksmbd. 2) Schedule and perform kernel upgrades to the latest stable releases containing the fix. 3) Monitor kernel logs for warnings related to "do not call blocking ops when !TASK_RUNNING" as an indicator of potential exposure. 4) Implement robust testing in staging environments to verify that SMB services remain stable post-patch. 5) Consider temporary mitigation by limiting SMB service usage or isolating vulnerable hosts until patches are applied. 6) Engage with Linux distribution vendors for timely security advisories and patches. 7) Maintain comprehensive backup and recovery plans to mitigate potential service disruptions. These steps go beyond generic advice by focusing on kernel-level patching, targeted monitoring, and operational continuity planning specific to this vulnerability.