CVE-2022-49758 is a vulnerability identified in the Linux kernel specifically related to the reset controller driver for the uniphier-glue platform. The issue arises from a potential null pointer dereference (null-ptr-deref) when the function resource_size(res) is called. This occurs if the platform_get_resource() function returns NULL, indicating that the requested hardware resource is not available or not properly defined. In such cases, the kernel code does not adequately check for a NULL pointer before dereferencing it, leading to a kernel crash or system instability. This vulnerability is a classic example of insufficient input validation in kernel device drivers, which can cause denial of service (DoS) conditions by crashing the kernel or triggering a kernel panic. The vulnerability affects specific versions of the Linux kernel as identified by the commit hashes provided, and has been resolved by adding proper NULL checks in the reset controller driver code. There are no known exploits in the wild at this time, and no CVSS score has been assigned yet. The vulnerability does not appear to require user interaction or authentication, but exploitation requires the presence of the vulnerable driver and the ability to trigger the faulty code path, which is typically possible only with local access or through specific hardware configurations.

For European organizations, the primary impact of CVE-2022-49758 is the potential for denial of service on systems running vulnerable Linux kernel versions with the uniphier-glue reset controller driver enabled. This could lead to unexpected system crashes, affecting availability of critical infrastructure, servers, or embedded devices that rely on this kernel version. While the vulnerability does not directly lead to privilege escalation or data confidentiality breaches, the resulting instability can disrupt business operations, especially in environments where uptime is critical such as telecommunications, industrial control systems, or embedded Linux devices used in manufacturing. Organizations using customized or embedded Linux distributions that include the affected driver are at higher risk. Since the vulnerability is triggered by a NULL pointer dereference, it is unlikely to be exploited remotely without prior access. However, attackers with local access or the ability to load kernel modules could cause system crashes, potentially as part of a broader attack to disrupt services or gain further foothold.

To mitigate this vulnerability, European organizations should first identify if their Linux systems use the uniphier-glue reset controller driver and verify the kernel versions against the affected commits. Applying the official patches or upgrading to a Linux kernel version where this issue is resolved is the most effective mitigation. For embedded systems or custom kernels, vendors should rebuild and redeploy updated kernel images with the fix included. Additionally, organizations should restrict local access to trusted users only, as exploitation requires local privileges or specific hardware interactions. Monitoring system logs for kernel oops or panic messages related to reset controller failures can help detect attempted exploitation. Implementing kernel lockdown features and secure boot can reduce the risk of unauthorized kernel module loading, which might be used to trigger the vulnerability. Finally, maintaining a robust patch management process and working closely with hardware and software vendors to receive timely updates is critical to prevent exploitation.