CVE-2024-41088 is a vulnerability identified in the Linux kernel's CAN (Controller Area Network) driver for the MCP251XFD device, specifically within the mcp251xfd_start_xmit() function. This function is responsible for transmitting CAN messages over an SPI (Serial Peripheral Interface) bus. The vulnerability arises when the transmission function fails, particularly under conditions where multiple devices share the same SPI interface and concurrent access to the bus occurs. In such scenarios, the driver enters an infinite loop because the interrupt routine does not return after a transmission failure, even if the application that initiated the transmission is terminated. The root cause is that the tx_ring->head pointer increments despite the failure in mcp251xfd_start_xmit(), causing the driver to skip a transmission package while still expecting a response in the transmit event FIFO handler (mcp251xfd_handle_tefif_one()). This leads to the driver continuously processing the same error state, resulting in an infinite loop and effectively halting message processing. The error manifests as repeated kernel log messages indicating transmission errors and FIFO buffer issues. The fix involves modifying the driver to handle the -EBUSY error by starting a workqueue to synchronously write the transmission object and, for other errors, decrementing the tx_ring->head, removing the socket buffer from the echo stack, and dropping the problematic message. This ensures the driver recovers gracefully from transmission failures and prevents the infinite loop condition. No known exploits are reported in the wild, and no CVSS score has been assigned yet.

For European organizations, this vulnerability primarily affects systems that rely on Linux-based embedded devices or industrial control systems using the MCP251XFD CAN controller over SPI interfaces. Such devices are common in automotive manufacturing, industrial automation, and critical infrastructure sectors where CAN bus communication is prevalent. The infinite loop condition can cause denial of service (DoS) on the affected device, leading to halted communications on the CAN bus, potentially disrupting operational technology (OT) environments or embedded systems. This could result in degraded system performance, loss of telemetry or control signals, and increased downtime. While the vulnerability does not directly expose confidentiality or integrity risks, the availability impact can be significant in safety-critical or real-time systems. European industries with extensive use of Linux-based embedded controllers in manufacturing plants, automotive testing facilities, or transportation infrastructure may face operational disruptions if this vulnerability is exploited or triggered unintentionally. Given the concurrency condition required to trigger the issue, the risk is more pronounced in complex multi-device SPI bus configurations.

Organizations should apply the official Linux kernel patches that address CVE-2024-41088 as soon as they become available in their distribution or vendor kernel updates. For embedded and industrial systems, ensure that firmware and kernel versions are updated to include this fix. Additionally, review and audit SPI bus configurations to minimize concurrent access conflicts, possibly by isolating devices or implementing access serialization where feasible. Monitoring kernel logs for repeated mcp251xfd transmission errors can help detect attempts to trigger this condition. In environments where immediate patching is not possible, consider implementing watchdog timers or fail-safe mechanisms to reset devices stuck in infinite loops. For development and testing, simulate concurrent SPI access scenarios to verify that the driver behaves correctly under failure conditions. Finally, coordinate with hardware vendors to confirm that their device firmware and drivers incorporate the fix and follow best practices for SPI bus arbitration.