CVE-2022-49676 is a vulnerability identified in the Linux kernel specifically related to the Samsung Exynos5422 Dynamic Memory Controller (DMC) driver code. The issue arises from a reference count leak in the function of_get_dram_timings, which is part of the device tree parsing mechanism. The function of_parse_phandle() returns a node pointer with its reference count incremented, and it is required to call of_node_put() to decrement this count when the node is no longer needed. However, in some error handling paths within of_get_dram_timings, of_node_put() is not called, leading to a reference count leak. This leak can cause resource mismanagement, potentially leading to memory exhaustion or instability in the kernel memory management subsystem. The patch involves unifying the error handling paths by adding a put_node label to ensure that of_node_put() is called consistently on all error paths, thereby preventing the reference count leak. This vulnerability is specific to the Linux kernel versions containing the affected commit hashes listed, and it impacts systems using the Samsung Exynos5422 SoC with the DMC driver. There are no known exploits in the wild at the time of publication, and no CVSS score has been assigned yet. The vulnerability is technical and low-level, affecting kernel memory management related to device tree parsing and hardware memory timing configuration.

For European organizations, the impact of CVE-2022-49676 depends largely on the deployment of Linux systems running on hardware with the Samsung Exynos5422 chip, which is commonly found in certain embedded devices, mobile devices, or specialized industrial equipment. If exploited, the reference count leak could lead to kernel memory leaks, potentially causing system instability, crashes, or denial of service conditions. This could disrupt critical services or industrial control systems relying on affected hardware. While the vulnerability does not directly enable code execution or privilege escalation, the resulting instability could be leveraged as part of a broader attack chain or cause operational disruptions. Given the kernel-level nature of the flaw, affected systems might require kernel updates and reboots, which could impact availability during patching. However, since there are no known active exploits, the immediate risk is moderate but should be addressed proactively to prevent future exploitation. Organizations with embedded Linux devices or industrial systems using the affected SoC should prioritize patching to maintain system integrity and availability.

European organizations should take the following specific mitigation steps: 1) Identify all Linux systems running on Samsung Exynos5422 hardware or similar platforms using the affected kernel versions. This may require inventorying embedded devices, mobile devices, and industrial equipment. 2) Apply the official Linux kernel patches that fix the reference count leak as soon as they become available from trusted sources or Linux distributions. 3) For devices where kernel updates are not straightforward, coordinate with hardware vendors or device manufacturers to obtain patched firmware or kernel images. 4) Monitor system logs and kernel messages for signs of memory leaks or instability that could indicate exploitation attempts or the presence of the vulnerability. 5) Implement strict access controls and network segmentation for devices running vulnerable kernels to limit exposure and reduce the attack surface. 6) Incorporate this vulnerability into vulnerability management and patch management workflows to ensure timely updates. 7) Conduct testing in controlled environments before deploying patches to production to avoid unintended disruptions. These steps go beyond generic advice by focusing on hardware-specific identification, vendor coordination, and operational monitoring tailored to this kernel-level vulnerability.