CVE-2022-48761 is a medium severity vulnerability in the Linux kernel's USB xHCI platform driver, specifically affecting the suspend/resume power management sequence on certain ARM-based platforms such as the Freescale i.MX8QM MEK. The issue arises when the system attempts to enter suspend mode with remote wakeup enabled on USB hubs. During suspend, the xhci_suspend function is called, which in turn calls xhci_disable_hub_port_wake to disable remote wakeup on USB hub ports. However, due to a recent kernel change (commit c1df456d0f06e) that removed automatic runtime resume calls before device suspend, the clock gating occurs prematurely. This means the clock to the USB controller is turned off before the driver accesses hardware registers to disable remote wakeup, leading to a synchronous external abort (hardware fault) and kernel crash. The root cause is a race condition between power domain management and runtime PM, causing register access with the clock gated off. The vulnerability can cause system instability and denial of service (DoS) by crashing the kernel during suspend operations on affected hardware. Exploitation requires local privileges with the ability to trigger suspend with remote wakeup enabled, and no user interaction is needed. The CVSS 3.1 score is 5.3 (medium), reflecting the local attack vector, low complexity, required privileges, and impact on confidentiality, integrity, and availability. No known exploits are reported in the wild yet. The patch involves ensuring runtime resume is called before suspend to keep the clock enabled when accessing registers, preventing the crash.

For European organizations, the primary impact of CVE-2022-48761 is potential denial of service on Linux systems running on affected ARM-based embedded platforms, particularly those using Freescale/NXP i.MX8QM or similar hardware. This could affect industrial control systems, IoT devices, telecommunications equipment, and embedded systems that rely on Linux kernel versions containing this flaw. A kernel crash during suspend could cause unexpected reboots or system downtime, impacting availability of critical infrastructure or services. Confidentiality and integrity impacts are limited but possible if the crash is leveraged as part of a larger attack chain. Organizations with embedded Linux devices in operational technology (OT) environments or edge computing nodes are at higher risk. The vulnerability requires local privileges, so attackers would need some level of access to the device. However, the medium severity and lack of known exploits reduce immediate risk for general IT environments. Still, the disruption potential in embedded or industrial contexts makes timely patching important to maintain system stability and availability.

1. Apply the official Linux kernel patches that address CVE-2022-48761, ensuring runtime resume is called before suspend to prevent clock gating issues. 2. For embedded devices or custom Linux builds, update the kernel to versions including the fix or backport the patch if upgrading is not feasible. 3. Audit and control local access to affected devices to prevent unauthorized users from triggering suspend with remote wakeup enabled. 4. Disable USB remote wakeup functionality on affected devices if not required, reducing the attack surface. 5. Implement monitoring for unexpected kernel crashes or reboots on embedded Linux systems to detect potential exploitation attempts. 6. Coordinate with hardware vendors (e.g., NXP) for firmware updates or advisories related to this issue. 7. For critical infrastructure, consider network segmentation and strict access controls to limit exposure of embedded Linux devices to untrusted users. 8. Test suspend/resume functionality thoroughly after patching to ensure system stability.