CVE-2024-50292 is a vulnerability identified in the Linux kernel specifically affecting the ALSA System on Chip (ASoC) driver for the STM32 SPDIFRX audio controller. The issue arises in the error handling path of the stm32_spdifrx_remove function, where the DMA (Direct Memory Access) channel release logic does not properly verify if the ctrl_chan pointer is valid before attempting to release it. In scenarios where the DMA channel request fails (indicated by error -19), the ctrl_chan pointer remains non-null but invalid. Consequently, the kernel attempts to release a DMA channel using an invalid pointer, leading to a NULL pointer dereference and a kernel crash (kernel panic). The kernel logs show error messages such as "dma_request_slave_channel error -19" followed by a NULL pointer dereference at a low virtual address, indicating a critical memory access violation. The call trace points to dma_release_channel and stm32_spdifrx_remove functions as the root cause. The vulnerability is resolved by adding a check to ensure the DMA channel pointer is valid before releasing it, preventing the kernel from dereferencing a NULL or invalid pointer. This flaw is a classic example of improper error handling in kernel device drivers that can cause system instability or denial of service. There are no known exploits in the wild currently, and no CVSS score has been assigned yet. The affected versions correspond to specific Linux kernel commits identified by their hashes, indicating the vulnerability is present in certain recent kernel builds prior to the patch. This vulnerability is relevant primarily to systems using the STM32 SPDIFRX audio controller driver, which is common in embedded Linux environments and certain industrial or IoT devices running Linux on STM32 microcontrollers.

For European organizations, the primary impact of CVE-2024-50292 is the potential for denial of service (DoS) on Linux systems utilizing the STM32 SPDIFRX audio controller driver. This could lead to unexpected kernel panics and system reboots, causing service interruptions. Organizations deploying embedded Linux devices in industrial control systems, telecommunications infrastructure, or IoT deployments that rely on STM32 hardware could face operational disruptions. Although this vulnerability does not directly lead to privilege escalation or remote code execution, the resulting instability could be exploited by attackers to cause outages or degrade service availability. In critical infrastructure sectors such as manufacturing, energy, or transportation within Europe, such disruptions could have cascading effects on operational continuity and safety. Additionally, the kernel crash could potentially be triggered by local users or processes with access to the affected device, increasing the risk of insider or accidental DoS. However, the scope is limited to systems with the specific hardware and driver combination, reducing the overall attack surface. Since no known exploits exist yet, the immediate risk is moderate, but timely patching is essential to prevent future exploitation.

European organizations should take the following specific mitigation steps: 1) Identify all Linux systems running STM32-based hardware that utilize the stm32_spdifrx driver, focusing on embedded and IoT devices. 2) Apply the official Linux kernel patches that fix the DMA channel release logic as soon as they become available in the stable kernel releases or backported to long-term support (LTS) kernels used in production. 3) For devices where kernel updates are not immediately feasible, implement monitoring to detect kernel panics or crashes related to the stm32_spdifrx driver and establish rapid recovery procedures. 4) Restrict access to affected devices and drivers to trusted users and processes to minimize the risk of accidental or malicious triggering of the vulnerability. 5) Engage with hardware and device vendors to confirm firmware and driver update availability and coordinate patch deployment. 6) Incorporate this vulnerability into vulnerability management and patching workflows, ensuring embedded Linux systems are not overlooked. 7) Consider network segmentation and isolation of critical embedded devices to limit the impact of potential DoS events. These targeted actions go beyond generic advice by focusing on the specific hardware and driver context of the vulnerability.