CVE-2022-48794 is a vulnerability identified in the Linux kernel specifically within the ieee802154 subsystem, which handles the at86rf230 radio transceiver driver. The issue arises during the transmission (Tx) process where, upon an error, the function ieee802154_xmit_complete() is not invoked as expected. Instead, only ieee802154_wake_queue() is called manually. This improper handling leads to a memory leak of the socket buffer (skb) structure, which is a fundamental data structure used in the Linux kernel networking stack to manage packets. The root cause is related to the timing and state management in the transmission completion handler, where the 'is_tx' flag cannot be safely moved due to potential race conditions between switching states (from transmission to reception mode) and new interrupts. To address this, the patch introduces an intermediate boolean 'was_tx' to safely track the transmission state and ensure that the skb is properly freed upon error conditions, preventing memory leaks. This vulnerability has existed for some time due to the complexity and frequent changes in this area of the kernel. While no direct exploit has been observed in the wild, the flaw could lead to resource exhaustion on affected systems if exploited, potentially degrading system performance or causing denial of service. The vulnerability affects Linux kernel versions identified by the commit hash 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and similar builds incorporating this code path. No CVSS score has been assigned yet, and no known public exploits are reported. The vulnerability is technical and low-level, impacting embedded or IoT devices using the ieee802154 protocol stack with at86rf230 radios, as well as other Linux systems that include this driver and feature set.

For European organizations, the impact of CVE-2022-48794 depends largely on the deployment of Linux systems utilizing the ieee802154 protocol and the at86rf230 radio transceiver. This protocol is commonly used in low-power wireless personal area networks, including some IoT and industrial control systems. Organizations in sectors such as manufacturing, smart grid utilities, and critical infrastructure that deploy embedded Linux devices with these radios could face risks of memory leaks leading to degraded device performance or denial of service. While the vulnerability does not directly enable remote code execution or data leakage, the resource exhaustion could disrupt operations, particularly in environments where device uptime and reliability are critical. European companies relying on Linux-based IoT devices in smart city deployments or industrial automation may experience operational interruptions if devices are not patched. However, the lack of known exploits and the specialized nature of the affected subsystem limit the immediate widespread impact. Nonetheless, unpatched devices in critical roles could be targeted for disruption by threat actors aiming to cause denial of service or degrade network reliability.

To mitigate CVE-2022-48794, European organizations should: 1) Identify and inventory all Linux-based devices and systems that utilize the ieee802154 protocol stack and specifically the at86rf230 radio driver. This includes embedded IoT devices, industrial controllers, and any custom Linux builds. 2) Apply the official Linux kernel patches that address this vulnerability as soon as they become available, or upgrade to a kernel version that includes the fix identified by the commit hash 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2. 3) For devices where kernel upgrades are not immediately feasible, implement monitoring for abnormal memory usage or resource exhaustion symptoms that could indicate exploitation attempts. 4) Collaborate with device manufacturers and vendors to ensure firmware updates incorporating the fix are deployed promptly. 5) Harden network segmentation to isolate vulnerable IoT or embedded devices from critical infrastructure and sensitive networks to limit potential impact. 6) Incorporate this vulnerability into vulnerability management and patch management workflows to ensure timely remediation. 7) Conduct security assessments of IoT deployments to evaluate exposure and implement compensating controls such as rate limiting or watchdog timers to mitigate denial of service risks.