CVE-2024-58042 is a vulnerability identified in the Linux kernel's rhashtable (resizable hash table) implementation. The issue arises from a potential deadlock scenario caused by nested locking dependencies involving the rhashtable bucket lock (rht lock), the runqueue lock (rq lock), and the deadline scheduling queue lock (dsq lock). Specifically, the original code performed a hash table growth check and scheduled work while still holding the rht lock. This created a circular locking dependency that could trigger lockdep warnings and potentially lead to deadlocks in kernel operations. The vulnerability was addressed by moving the hash table growth check and the scheduling of work outside the rht lock, thereby breaking the circular locking chain. Additionally, the atomic increment operation (atomic_inc) was also moved outside the bucket lock to further reduce locking contention. This fix enhances the flexibility of the rhashtable by removing restrictive locking constraints that previously limited its use in scheduler and workqueue contexts. The vulnerability does not appear to have known exploits in the wild and does not have an assigned CVSS score. The affected versions are identified by specific Linux kernel commit hashes, indicating that this is a low-level kernel synchronization issue rather than a user-facing vulnerability. The fix improves kernel stability and reliability by preventing potential deadlocks that could arise under certain concurrency conditions in kernel subsystems relying on rhashtable structures.

For European organizations, the primary impact of this vulnerability lies in system stability and availability rather than direct compromise of confidentiality or integrity. Linux is widely used across European enterprises, government agencies, and critical infrastructure, especially in servers, cloud environments, and embedded systems. A deadlock in the kernel scheduler or workqueue subsystem could cause system hangs or crashes, leading to denial of service conditions. This could disrupt business operations, cloud services, or critical infrastructure systems relying on Linux-based platforms. While there is no indication that this vulnerability can be exploited to gain unauthorized access or escalate privileges, the risk of system unavailability could affect service continuity and operational resilience. Organizations with high-availability requirements or those running large-scale Linux deployments should be particularly attentive. The absence of known exploits reduces immediate risk, but the potential for deadlocks under specific workloads means that systems with heavy concurrency or complex scheduling could be vulnerable to stability issues if unpatched.

European organizations should prioritize updating their Linux kernel to versions that include the patch for CVE-2024-58042. Since this is a kernel-level fix, applying the latest stable kernel releases from trusted Linux distributions is the most effective mitigation. Organizations should: 1) Identify all Linux systems in their environment, including servers, virtual machines, containers, and embedded devices. 2) Verify kernel versions and apply vendor-supplied updates or compile kernels with the fix if using custom builds. 3) Test kernel updates in staging environments to ensure compatibility and stability before production rollout. 4) Monitor system logs for lockdep warnings or unusual scheduler behavior that might indicate deadlock conditions. 5) For critical systems, implement redundancy and failover mechanisms to mitigate potential downtime caused by kernel deadlocks. 6) Engage with Linux distribution vendors to confirm patch availability and deployment timelines. 7) Avoid running untrusted or experimental kernel modules that might interact with rhashtable structures until patched. These steps go beyond generic advice by focusing on kernel version management, proactive monitoring for deadlock symptoms, and operational continuity planning.