CVE-2024-56543 is a vulnerability identified in the Linux kernel's ath12k wireless driver, which is responsible for managing Qualcomm Atheros Wi-Fi chipsets. The flaw arises during the cleanup process of receive traffic identifiers (Rx TIDs) associated with wireless peers. Specifically, when the core halts, the driver performs a cleanup of all peers' Rx TIDs. However, the self peer (the local device itself) does not undergo the usual data path (dp) setup during peer creation, leading to an invalid access of the rx_tid::ab field during cleanup. This results in a kernel warning and a stack trace indicating an invalid operation exception. The root cause is that the cleanup code does not properly skip the self peer, causing it to access uninitialized or invalid memory structures. The vulnerability was observed and tested on Qualcomm chipsets QCN9274 and WCN7850. The fix involves detecting the self peer using the peer::sta object and skipping the Rx TID cleanup for it, preventing the invalid memory access and associated kernel crash. Although no known exploits are reported in the wild, the issue can cause system instability or denial of service due to kernel crashes triggered by malformed or unexpected wireless peer states. This vulnerability affects Linux kernel versions containing the specified commit hashes prior to the patch and is relevant to systems using the ath12k driver for Qualcomm Atheros Wi-Fi hardware.

For European organizations, this vulnerability poses a risk primarily to systems running Linux with Qualcomm Atheros Wi-Fi chipsets managed by the ath12k driver. The impact includes potential denial of service conditions caused by kernel panics or crashes when the wireless driver mishandles self peer cleanup. This can disrupt network connectivity, leading to loss of productivity, interruption of critical services, and potential cascading failures in network-dependent applications. In environments such as enterprises, research institutions, and public sector organizations where Linux-based systems are prevalent, especially those relying on wireless connectivity, this could degrade operational stability. Additionally, embedded Linux devices or IoT infrastructure using affected chipsets may experience similar disruptions. While no direct remote code execution or privilege escalation is indicated, the denial of service impact on availability is significant, particularly for mission-critical systems. The lack of known exploits reduces immediate risk, but the vulnerability should be addressed promptly to prevent potential exploitation or accidental triggering in complex network environments.

To mitigate CVE-2024-56543, organizations should: 1) Apply the latest Linux kernel updates that include the patch for this vulnerability, ensuring the ath12k driver is updated to the fixed version. 2) Identify and inventory all Linux systems using Qualcomm Atheros Wi-Fi chipsets with the ath12k driver, prioritizing those in critical network roles. 3) For embedded or IoT devices where kernel updates may be delayed, consider network segmentation or disabling affected wireless interfaces if feasible to reduce exposure. 4) Monitor system logs for kernel warnings or crashes related to ath12k, which may indicate attempted exploitation or instability. 5) Engage with hardware and distribution vendors to confirm patch availability and deployment timelines. 6) Implement robust backup and recovery procedures to minimize downtime in case of service disruption. 7) Consider temporary mitigation by disabling wireless interfaces or switching to alternative drivers if supported until patches are applied. These steps go beyond generic advice by focusing on chipset-specific driver updates, proactive system inventory, and operational continuity planning.