CVE-2025-22075 is a vulnerability identified in the Linux kernel's rtnetlink subsystem, specifically related to the handling of Virtual Function (VF) GUIDs in netlink ifinfo messages. The vulnerability arises because the kernel code added support for retrieving VF port and node GUIDs but failed to properly account for the increased size of these GUIDs when allocating memory for netlink messages. This oversight leads to a situation where netlink messages can become too large to be handled correctly, resulting in errors such as "RTNETLINK answers: Message too long" and kernel warnings or crashes. The root cause is an insufficient allocation size for netlink messages when many VF GUIDs are present, causing the kernel to emit warnings and potentially leading to denial of service due to kernel warnings or crashes triggered by malformed or oversized netlink messages. The vulnerability is triggered when commands like "ip link show dev ib0" are executed on devices with many VFs configured (e.g., via sriov_numvfs). The detailed kernel warning and stack trace indicate that the issue occurs in the rtnl_getlink function, which is responsible for processing netlink link messages. While no known exploits are currently reported in the wild, the vulnerability could be leveraged to disrupt network management operations or cause kernel instability on affected systems. The affected versions correspond to a specific commit (30aad41721e0) in the Linux kernel source, indicating that this issue is present in kernel versions including or derived from this commit. The vulnerability affects Linux kernel installations that utilize SR-IOV (Single Root I/O Virtualization) with multiple virtual functions, particularly in environments using InfiniBand or similar network interfaces that expose VF GUIDs via rtnetlink. This vulnerability is primarily a denial-of-service risk due to kernel warnings and potential crashes, rather than a direct code execution or privilege escalation flaw.

For European organizations, the impact of CVE-2025-22075 could be significant in environments relying on Linux servers with SR-IOV enabled network interfaces, especially those using InfiniBand or advanced networking hardware supporting virtual functions. Data centers, cloud providers, and enterprises with high-performance computing clusters or virtualized infrastructure could experience service disruptions due to kernel warnings or crashes triggered by this vulnerability. This could lead to network management failures, degraded network performance, or unplanned downtime affecting critical business operations. Since the vulnerability causes denial of service rather than direct data compromise, the confidentiality and integrity impact is limited; however, availability impact could be substantial, particularly for organizations with strict uptime requirements. Additionally, troubleshooting and remediation efforts may require kernel updates and careful validation to avoid operational disruptions. The lack of known exploits reduces immediate risk, but the vulnerability should be addressed proactively to prevent potential exploitation or accidental triggering during routine network management tasks.

To mitigate CVE-2025-22075, European organizations should: 1) Apply the latest Linux kernel patches that address this issue as soon as they become available, ensuring that the netlink message allocation properly accounts for VF GUID sizes. 2) In the interim, limit the number of virtual functions configured on affected network devices to reduce the likelihood of triggering the message size limitation. 3) Monitor kernel logs for rtnetlink warnings or errors related to message size or VF GUID handling to detect potential attempts to exploit or inadvertently trigger the vulnerability. 4) Implement strict access controls on systems with SR-IOV enabled to restrict who can execute network management commands that interact with rtnetlink interfaces, reducing the risk of accidental or malicious triggering. 5) Test kernel updates in staging environments that mirror production to ensure stability and compatibility, especially in complex networking setups involving SR-IOV and InfiniBand. 6) Coordinate with hardware vendors for firmware or driver updates that may complement kernel fixes and improve VF GUID handling robustness. 7) Document and train network administrators on the implications of this vulnerability and the importance of cautious configuration of virtual functions.