CVE-2022-49917 is a vulnerability identified in the Linux kernel specifically related to the IP Virtual Server (IPVS) subsystem. The issue arises during the initialization and cleanup phases of the ip_vs_app module. During the initialization function ip_vs_app_net_init(), if the creation of the ip_vs_app proc file fails, the initialization process still reports success by default. This leads to a scenario where the ip_vs_app proc file does not exist when the cleanup function ip_vs_app_net_cleanup() attempts to remove it. The absence of the file triggers a warning in the kernel logs, specifically a WARNING at fs/proc/generic.c in the remove_proc_entry function. The stack trace indicates that this warning occurs during the cleanup of network namespaces and workqueue processing. While the vulnerability does not appear to cause a kernel panic or direct denial of service, the warning indicates improper handling of resource cleanup which could potentially lead to resource leaks or instability under certain conditions. The vulnerability does not have an associated CVSS score and there are no known exploits in the wild. The affected versions are identified by specific commit hashes, indicating this is a code-level bug fixed in recent Linux kernel updates. The root cause is a logic flaw in error handling during proc file creation and cleanup in the IPVS kernel module.

For European organizations, the impact of CVE-2022-49917 is primarily related to system stability and reliability rather than direct compromise or data breach. Linux servers running IPVS, commonly used for load balancing and high availability in data centers and cloud environments, may experience kernel warnings that could complicate troubleshooting and monitoring. In large-scale deployments, repeated warnings could mask other critical kernel messages or contribute to degraded system performance. While no direct exploitation is known, the improper cleanup could theoretically be leveraged in complex attack scenarios to cause resource exhaustion or kernel instability, impacting availability. Organizations relying heavily on Linux-based load balancers or network appliances with IPVS enabled should be aware of this vulnerability. The impact on confidentiality and integrity is minimal as the vulnerability does not provide privilege escalation or code execution vectors. However, availability could be affected if the issue leads to kernel instability under specific workloads.

To mitigate CVE-2022-49917, European organizations should prioritize updating their Linux kernels to versions where this vulnerability is patched. Since the issue stems from a logic flaw in the IPVS module, applying the latest stable kernel releases or backported security patches from trusted Linux distributions is essential. System administrators should verify that IPVS is properly configured and monitor kernel logs for warnings related to ip_vs_app during initialization and cleanup phases. Disabling IPVS if not in use can reduce the attack surface. Additionally, implementing robust kernel monitoring and alerting can help detect abnormal warnings early. For environments with custom kernel builds, reviewing and testing the IPVS module code for proper error handling during proc file creation and cleanup is recommended. Finally, maintaining comprehensive backup and recovery procedures ensures resilience in case of system instability.