CVE-2022-49927 is a vulnerability identified in the Linux kernel's NFSv4 (Network File System version 4) client implementation. Specifically, the issue arises in the memory management of slot allocations within the NFSv4 client code. When the kernel attempts to allocate a slot and the allocation fails, the existing allocated slots are not properly cleaned up, resulting in a memory leak. This is evidenced by unreferenced kernel memory objects associated with the mount.nfs process, which can accumulate over time if the failure condition is triggered repeatedly. The root cause is improper error handling in the nfs4_find_or_create_slot and nfs4_realloc_slot_table functions, where failure to allocate a new slot does not trigger cleanup of previously allocated slots. This can lead to kernel memory leaks, which in turn may degrade system performance or stability. The vulnerability does not appear to allow direct code execution or privilege escalation but can cause resource exhaustion in affected systems. The issue was resolved by ensuring that all allocated slots are cleaned up if any slot allocation fails, preventing the leak. The vulnerability affects specific Linux kernel versions identified by commit hashes, and no known exploits are currently reported in the wild. The vulnerability was published on May 1, 2025, and no CVSS score has been assigned yet.

For European organizations, the impact of CVE-2022-49927 primarily concerns systems running Linux kernels with the vulnerable NFSv4 client code, especially those heavily reliant on NFS mounts for networked storage. Memory leaks in kernel space can lead to gradual degradation of system performance, increased memory consumption, and potential system instability or crashes if the leak is severe and sustained. This can disrupt critical services, particularly in environments with high NFS usage such as data centers, cloud providers, and enterprises using Linux-based file servers or clients. While this vulnerability does not directly enable remote code execution or privilege escalation, the resulting denial of service through resource exhaustion could impact availability of services. European organizations with large-scale Linux deployments, including government agencies, financial institutions, and telecommunications providers, may experience operational disruptions if this vulnerability is exploited or triggered inadvertently. The lack of known exploits reduces immediate risk, but unpatched systems remain vulnerable to potential future exploitation or accidental triggering of the leak under heavy load conditions.

To mitigate CVE-2022-49927, European organizations should prioritize updating their Linux kernel versions to those containing the patch that properly handles slot allocation failures in the NFSv4 client code. Kernel upgrades should be tested and deployed promptly in production environments. Additionally, organizations should monitor system memory usage and kernel logs for signs of memory leaks or abnormal behavior related to NFS mounts. Implementing resource limits and watchdog mechanisms can help detect and recover from potential memory exhaustion scenarios. For environments where immediate kernel upgrades are not feasible, reducing reliance on NFSv4 mounts or limiting the number of concurrent NFS sessions may reduce exposure. Network segmentation and strict access controls on NFS servers can also limit the attack surface. Finally, maintaining an up-to-date inventory of Linux kernel versions in use and applying security patches as part of regular maintenance cycles will help prevent exploitation of this and similar vulnerabilities.