CVE-2024-35833 is a medium-severity vulnerability identified in the Linux kernel's dmaengine subsystem, specifically affecting the fsl-qdma driver. The issue arises from a memory leak caused by improper handling of dma_alloc_coherent() allocations. In the affected code paths, the allocated DMA-coherent memory is not freed either in the driver's remove function or in the error handling path of the fsl_qdma_probe() function. This leads to a gradual consumption of system memory resources when the driver is loaded and unloaded or when initialization errors occur. The root cause is the failure to switch to the managed DMA API, which would automatically handle the release of allocated resources, thereby preventing leaks. The vulnerability does not impact confidentiality or integrity but affects availability due to resource exhaustion. The CVSS 3.1 vector (AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H) indicates that the attack requires local access with low privileges and no user interaction, and the impact is limited to availability. No known exploits are currently reported in the wild. The affected versions correspond to specific Linux kernel commits prior to the fix. The patch involves switching to the managed DMA API to ensure proper cleanup of allocated memory in all code paths.

For European organizations, this vulnerability could lead to denial-of-service conditions on Linux systems running the affected kernel versions, particularly those using the fsl-qdma driver for DMA operations. Systems experiencing repeated driver reloads or initialization failures may suffer from memory leaks that degrade system performance or cause crashes. This can impact critical infrastructure, servers, embedded devices, or industrial control systems relying on Linux kernels with this driver. While the vulnerability does not allow privilege escalation or data compromise, the availability impact could disrupt business operations, especially in environments where uptime and reliability are critical. Organizations using Linux in embedded or specialized hardware contexts (e.g., telecommunications, manufacturing, or automotive sectors) may be more exposed due to the use of the fsl-qdma driver. The lack of known exploits reduces immediate risk, but the presence of a fix means timely patching is advisable to prevent potential future exploitation or operational issues.

European organizations should identify Linux systems running kernel versions that include the vulnerable fsl-qdma driver. They should apply the official Linux kernel patches that switch the driver to use the managed DMA API, which ensures proper resource cleanup. For systems where immediate patching is not feasible, monitoring for abnormal memory usage or system instability related to DMA operations can help detect potential issues. Additionally, limiting local access to trusted users reduces the risk of exploitation since the vulnerability requires local privileges. Organizations should incorporate this fix into their regular kernel update cycles and validate that embedded or specialized devices receive firmware or kernel updates addressing this vulnerability. Where possible, testing updated kernels in staging environments before deployment will help ensure stability. Finally, documenting and auditing driver usage and system logs can assist in early detection of memory leak symptoms.