CVE-2025-22061 is a vulnerability identified in the Linux kernel specifically related to the 'airoha' Ethernet driver, which handles HTB (Hierarchical Token Bucket) offloading for traffic control. The issue arises in the function 'airoha_tc_get_htb_get_leaf_queue', which improperly reports the queue ID (qid) when deleting HTB offloaded leaf or root qdiscs (queueing disciplines). This improper handling leads to kernel warnings and potentially unstable behavior, as evidenced by the kernel stack trace and warning messages included in the report. The vulnerability manifests when commands manipulating HTB offload qdiscs are executed, such as adding or deleting qdiscs and classes via the 'tc' (traffic control) utility. The kernel warning and trace indicate a use-after-free or invalid pointer dereference scenario during qdisc destruction and grafting operations, which could lead to kernel crashes (denial of service) or unpredictable kernel behavior. The vulnerability affects Linux kernel version 6.6.71 and possibly other versions containing the affected commit (ef1ca9271313b4ea7b03de69576aacef1e78f381). No known exploits are currently reported in the wild, and no CVSS score has been assigned yet. The vulnerability is technical and low-level, involving network traffic control subsystems and driver-specific code for Airoha Ethernet hardware, which is used in certain embedded or specialized devices. The fix involves correcting the qid reporting logic to prevent kernel warnings and ensure proper qdisc deletion without corrupting kernel state.

For European organizations, the primary impact of CVE-2025-22061 is the potential for denial of service (DoS) on Linux systems running the affected kernel versions with Airoha Ethernet hardware and utilizing HTB offloading for traffic control. This could disrupt network traffic management, leading to degraded network performance or outages in critical infrastructure, data centers, or enterprise networks. While the vulnerability does not appear to allow privilege escalation or remote code execution directly, kernel crashes can cause system instability and downtime, impacting availability. Organizations relying on embedded Linux devices or specialized network equipment using the Airoha driver are at higher risk. The vulnerability could affect network appliances, IoT gateways, or telecom equipment deployed in European enterprises or service providers. Given the lack of known exploits, the immediate risk is moderate, but the potential for targeted attacks exploiting this flaw in critical network infrastructure cannot be discounted. The impact on confidentiality and integrity is low, but availability impact is medium to high depending on the deployment context.

European organizations should take the following specific mitigation steps: 1) Identify Linux systems running kernel versions 6.6.71 or other versions containing the vulnerable commit and verify if the Airoha Ethernet driver is in use, especially in network appliances or embedded devices. 2) Apply kernel updates or patches from the Linux vendor or distribution maintainers that address this vulnerability as soon as they become available. 3) If immediate patching is not possible, disable HTB offloading on affected interfaces as a temporary workaround to prevent triggering the vulnerable code path. 4) Monitor system logs for kernel warnings related to qdisc operations and investigate any anomalies promptly. 5) Limit administrative access to systems performing traffic control operations to reduce the risk of exploitation via crafted 'tc' commands. 6) Engage with hardware vendors to confirm if firmware or driver updates are required for devices using Airoha Ethernet components. 7) Incorporate this vulnerability into vulnerability management and incident response plans to ensure timely detection and remediation.