CVE-2024-46675 is a vulnerability identified in the Linux kernel's USB core driver, specifically affecting the DesignWare Core USB3 (dwc3) controller implementation on Exynos platforms. The vulnerability arises during the runtime suspend process of the USB core. The issue occurs because the USB core may attempt to access an invalid event buffer address if the software clears the event buffer address prematurely while the USB core is still active. This sequence can lead to System Memory Management Unit (SMMU) faults and other memory-related errors. The root cause is a timing window where the USB core is transitioning to a halt state but may experience a timeout, and the event buffer is cleared regardless of the USB core's actual status. This improper clearing can cause the hardware to access invalid memory addresses, potentially leading to system instability or crashes. The patch for this vulnerability ensures that the event buffer address is only cleared after verifying that the USB core is inactive, preventing invalid memory access during runtime suspend. This fix addresses a hardware quirk specific to Exynos platforms, which are Samsung's ARM-based SoCs commonly used in mobile and embedded devices. Although the vulnerability is specific to certain hardware, it resides in the Linux kernel codebase, which is widely used across many devices and distributions. No known exploits are currently reported in the wild, and the vulnerability was published on September 13, 2024.

For European organizations, the impact of CVE-2024-46675 depends largely on their use of Linux-based systems running on Exynos hardware or similar ARM-based platforms incorporating the affected USB controller. Organizations deploying embedded systems, mobile devices, or specialized hardware using Exynos SoCs could experience system instability, crashes, or denial of service conditions due to SMMU faults triggered by this vulnerability. This could affect operational continuity, especially in sectors relying on embedded Linux devices such as telecommunications, industrial control systems, and IoT deployments. While the vulnerability does not directly expose data confidentiality or integrity risks, the potential for system crashes or denial of service could disrupt critical services or processes. Since the flaw is hardware-specific and requires the USB core to enter a runtime suspend state, exploitation is somewhat constrained but still relevant for affected platforms. European organizations using standard x86 Linux servers or non-Exynos ARM platforms are unlikely to be impacted. However, given the widespread use of Linux in various environments, organizations should assess their hardware inventory carefully. The absence of known exploits reduces immediate risk but does not eliminate the need for timely patching to prevent future exploitation or accidental system failures.

1. Apply the official Linux kernel patch that addresses CVE-2024-46675 as soon as it becomes available in your distribution's updates. This patch ensures the event buffer address is not cleared while the USB core is active, preventing invalid memory access. 2. Identify and inventory all systems running Linux kernels on Exynos platforms or devices using the dwc3 USB controller to prioritize patch deployment. 3. For embedded or mobile devices where kernel updates may be delayed, consider implementing runtime monitoring for USB subsystem errors or SMMU faults to detect potential exploitation or instability early. 4. Coordinate with hardware vendors and device manufacturers to obtain updated firmware or kernel versions that include the fix. 5. Limit runtime suspend states on affected devices if feasible, as a temporary workaround to reduce exposure until patches are applied. 6. Conduct thorough testing of updated kernels in staging environments to ensure stability and compatibility, especially for critical embedded systems. 7. Maintain strong operational procedures for incident response to quickly address any system crashes or anomalies potentially related to this vulnerability.