CVE-2022-49646 is a vulnerability identified in the Linux kernel's mac80211 wireless subsystem, specifically affecting queue selection for mesh and Outside the Context of a BSS (OCB) interfaces. The issue arises from the handling of broadcast packet queues when using the iTXQ (transmit queue) mechanism. The kernel code assumes that there is only one virtual interface (vif) queue for broadcast packets, which is the Best Effort (BE) queue. However, if non-BE queue markings are used, this assumption is violated, causing a mismatch between the transmit queue's access category (txq->ac) and the socket buffer's queue mapping (skb_queue_mapping). This discrepancy can lead to improper queue handling within the wireless driver and triggers warnings related to the recent Automatic Queue Length (AQL) changes, specifically an AQL underflow warning. Although the vulnerability does not directly indicate a memory corruption or privilege escalation, the improper queue handling could potentially cause packet loss, degraded wireless performance, or instability in wireless communications on affected Linux systems. The vulnerability affects Linux kernel versions identified by the commit hash 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, and no known exploits are currently reported in the wild. The issue was publicly disclosed on February 26, 2025, but no CVSS score has been assigned yet.

For European organizations, this vulnerability could impact any systems running affected Linux kernel versions with wireless mesh or OCB interfaces enabled, particularly in environments relying on wireless networking for critical communications, such as industrial control systems, public safety networks, or enterprise Wi-Fi infrastructures. The improper queue handling could lead to intermittent wireless connectivity issues, packet loss, or degraded network performance, which may disrupt business operations or critical services. While there is no evidence of direct exploitation leading to privilege escalation or data breaches, the instability caused by this flaw could be leveraged in denial-of-service scenarios or to degrade the reliability of wireless communications. Organizations using Linux-based wireless routers, access points, or embedded devices in mesh networks should be particularly vigilant. The impact is more pronounced in sectors with high dependency on wireless mesh networks, such as smart city deployments, transportation systems, and large-scale enterprise wireless environments common in Europe.

To mitigate this vulnerability, European organizations should prioritize updating their Linux kernel to the latest patched version that addresses CVE-2022-49646. Since the vulnerability relates to the mac80211 subsystem and queue handling, kernel updates from trusted Linux distributions should be applied promptly. Network administrators should audit their wireless configurations to identify the use of mesh or OCB interfaces and assess whether non-BE queue markings are in use. If feasible, temporarily disabling mesh or OCB interfaces or restricting broadcast packet queue markings to the BE queue can reduce exposure until patches are applied. Additionally, monitoring wireless network logs for AQL underflow warnings or unusual queue handling errors can help detect potential exploitation attempts or instability. For embedded devices or appliances running custom Linux kernels, vendors should be contacted to ensure timely firmware updates. Implementing network segmentation to isolate critical wireless infrastructure and employing redundancy in wireless mesh networks can also help mitigate potential service disruptions caused by this vulnerability.