CVE-2024-46675: 
Linux Kernel vulnerability analysis and mitigation

CVE-2024-46675 is a vulnerability in the Linux kernel's USB core component, specifically affecting the DWC3 (DesignWare USB3) driver. The vulnerability was discovered and disclosed in September 2024, affecting multiple versions of the Linux kernel from 4.19.x through 6.11.x. The issue occurs during runtime suspend operations where the USB core could potentially access an invalid event buffer address (NVD).

The vulnerability stems from a sequence of events in the USB core's operation. During dwc3gadgetsuspend execution, there is a possibility of a timeout when attempting to move the USB core to the halt state after clearing the run/stop bit by software. In dwc3coreexit, the event buffer is cleared regardless of the USB core's status, which can lead to SMMU faults and other memory issues if the USB core attempts to access the event buffer address. This issue particularly affects Exynos platforms. The vulnerability has been assigned a CVSS v3.1 base score of 5.5 (Medium) with vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H (NVD).

The vulnerability can cause SMMU (System Memory Management Unit) faults and other memory-related issues in affected systems, particularly on Exynos platforms. When exploited, it can lead to a denial of service condition by causing system crashes or memory corruption during USB device runtime suspend operations (NVD).

A patch has been developed and committed to the Linux kernel that prevents the USB core from accessing invalid event buffer addresses during runtime suspend. The fix ensures that the event buffer address is not cleared by software when the USB core is active during runtime suspend by checking its status before clearing the buffer address. This is implemented by adding a check for the USB core's halt state before proceeding with event buffer cleanup (Kernel Patch).