CVE-2022-48952 is a vulnerability identified in the Linux kernel specifically related to the PCI driver for the MediaTek MT7621 System on Chip (SoC). The issue arises from the absence of a sentinel value in the soc_device_attribute array within the mt7621 PCI quirks driver. This sentinel is necessary to properly terminate the array that is used by the soc_device_match function during device matching operations. Without this sentinel, the kernel attempts to access beyond the intended array bounds, leading to a kernel oops (a type of kernel crash). This vulnerability was introduced or became exposed after a prior fix (commit 7c18b64bba3b) that corrected the registration of the MT7621 SoC as a device, which changed how the soc_device_match function processes the quirks table. The root cause is a missing sentinel in the quirks table array, which is a programming oversight in the driver code. The impact of this flaw is primarily a denial-of-service condition caused by a kernel crash when the affected driver code is executed. There is no indication that this vulnerability allows for privilege escalation, arbitrary code execution, or data leakage. The vulnerability affects specific Linux kernel versions containing the affected driver code and the MT7621 SoC platform. No known exploits are currently reported in the wild, and no CVSS score has been assigned to this vulnerability yet. The fix involves adding the required sentinel value to the quirks table array to prevent out-of-bounds access and subsequent kernel oops.

For European organizations, the primary impact of CVE-2022-48952 is the potential for denial-of-service (DoS) on systems running Linux kernels with the affected MT7621 PCI driver. The MT7621 SoC is commonly used in embedded devices such as routers, gateways, and network appliances. Organizations relying on such devices with Linux-based firmware that includes this vulnerable driver could experience unexpected system crashes, leading to network outages or degraded service availability. This could affect critical infrastructure components, especially in sectors like telecommunications, industrial control systems, and enterprise networking where embedded Linux devices are prevalent. However, since the vulnerability does not appear to allow code execution or privilege escalation, the risk of data breaches or system compromise is low. The absence of known exploits in the wild reduces immediate threat levels but does not eliminate the risk of future exploitation attempts. Organizations using custom or vendor-provided Linux distributions on MT7621-based hardware should assess their exposure and prioritize patching to maintain operational stability and avoid service disruptions.

1. Identify all devices and systems within the organization that use the MediaTek MT7621 SoC running Linux kernels with the affected driver versions. This includes embedded routers, network appliances, and IoT devices. 2. Apply the official Linux kernel patches that add the missing sentinel to the mt7621 PCI quirks table as soon as they become available from trusted sources or vendor firmware updates. 3. For devices where kernel patching is not immediately feasible, consider temporary network segmentation or isolation to limit exposure and reduce the risk of triggering the vulnerability. 4. Monitor system logs and kernel messages for signs of kernel oops or crashes related to the mt7621_pcie_quirks_match function. 5. Engage with device vendors to obtain updated firmware versions that incorporate the fix. 6. Implement robust device inventory and configuration management to track embedded Linux devices and their kernel versions. 7. Conduct regular vulnerability assessments and penetration tests focusing on embedded device firmware to detect similar issues proactively.