CVE-2022-48915 is a vulnerability identified in the Linux kernel's thermal management subsystem. Specifically, the issue arises in the thermal core component where a NULL pointer dereference can occur due to improper handling of thermal zone trip points. The vulnerability is triggered when the function thermal_genl_cmd_tz_get_trip() calls get_trip_hyst() without verifying whether the thermal zone defines this function, leading to a NULL pointer dereference. This can cause the kernel to crash or become unstable, resulting in a denial of service (DoS) condition. The flaw is rooted in the thermal management code that handles temperature thresholds (trip points) for thermal zones, which are critical for system stability and hardware protection. The patch resolves the issue by adding a check to ensure get_trip_hyst() is only called if the thermal zone defines it, preventing the NULL pointer dereference. Although no known exploits are currently reported in the wild, the vulnerability affects Linux kernel versions prior to the patch and could be triggered by local users or processes interacting with the thermal subsystem. Since the thermal subsystem is part of the core kernel, this vulnerability potentially impacts a wide range of Linux-based systems, including servers, desktops, and embedded devices that rely on Linux for thermal management.

For European organizations, the impact of CVE-2022-48915 primarily involves potential system instability or crashes due to kernel panics caused by the NULL pointer dereference in the thermal subsystem. This can lead to denial of service, affecting availability of critical systems. Organizations running Linux servers, especially those in data centers, cloud environments, or industrial control systems, may experience unexpected downtime or degraded performance. Given the thermal subsystem's role in hardware protection, improper handling could also risk hardware damage if thermal thresholds are not correctly managed. Although exploitation requires interaction with the thermal subsystem, which may limit remote exploitation, local privilege escalation or malicious local processes could trigger the vulnerability. This risk is particularly relevant for multi-tenant environments or systems with untrusted local users. The lack of known exploits reduces immediate risk, but the widespread use of Linux in European enterprises, government agencies, and critical infrastructure means that patching is essential to maintain operational continuity and security compliance.

To mitigate CVE-2022-48915, European organizations should promptly apply the official Linux kernel patches that address the NULL pointer dereference in the thermal subsystem. Kernel updates should be tested and deployed in a timely manner across all affected systems. For environments where immediate patching is not feasible, organizations can limit access to interfaces that interact with the thermal subsystem, restricting local user permissions and employing strict access controls to reduce the risk of exploitation. Monitoring system logs for kernel panics or thermal subsystem errors can help detect attempts to trigger the vulnerability. Additionally, organizations should ensure that their Linux distributions are up to date with vendor security advisories and consider using kernel live patching solutions where available to minimize downtime. Regular security audits and vulnerability scanning should include checks for this specific kernel version to identify unpatched systems. Finally, educating system administrators about the importance of thermal subsystem security and proper patch management will enhance overall resilience.