CVE-2024-38546 is a vulnerability identified in the Linux kernel, specifically within the Direct Rendering Manager (DRM) subsystem's vc4 driver, which handles video output for Broadcom's VideoCore IV GPUs commonly found in devices like the Raspberry Pi. The flaw arises in the function vc4_hdmi_audio_init(), where the call to of_get_address() can return a NULL pointer. This NULL pointer is subsequently dereferenced without a proper check, leading to a potential null pointer dereference vulnerability. Such a dereference can cause the kernel to crash or panic, resulting in a denial of service (DoS) condition. The vulnerability was discovered by the Linux Verification Center using static analysis tools (SVACE). The issue has been addressed by adding a NULL check to prevent dereferencing a NULL pointer. The affected versions correspond to specific Linux kernel commits identified by the hash bb7d78568814a31a11fa14f1479a9fe51f1582ad. There are no known exploits in the wild at the time of publication, and no CVSS score has been assigned yet. The vulnerability does not appear to allow privilege escalation or code execution directly but can impact system stability and availability.

For European organizations, the primary impact of this vulnerability is the risk of system instability or denial of service on Linux systems utilizing the vc4 DRM driver, particularly those running on hardware with Broadcom VideoCore IV GPUs such as Raspberry Pi devices. This could affect embedded systems, IoT devices, or specialized computing environments that rely on these platforms. While the vulnerability does not directly compromise confidentiality or integrity, the availability impact could disrupt critical services or operations, especially in industrial, educational, or research environments where such hardware is prevalent. Organizations using Linux servers or desktops without this specific hardware are unlikely to be affected. The absence of known exploits reduces immediate risk, but unpatched systems remain vulnerable to potential future exploitation or accidental crashes triggered by malformed device tree data or hardware configurations.

European organizations should promptly apply the official Linux kernel patches that include the NULL pointer check in the vc4_hdmi_audio_init() function. For environments using custom or long-term support kernels, backporting the patch is recommended. Additionally, organizations should audit their Linux systems to identify devices running the vc4 driver, especially Raspberry Pi or similar hardware, and prioritize patching those systems. Implementing kernel crash monitoring and alerting can help detect exploitation attempts or accidental crashes. Where feasible, isolating critical systems using affected hardware from untrusted networks can reduce exposure. Regularly updating device firmware and ensuring device tree configurations are validated can also mitigate risks related to malformed inputs triggering the vulnerability. Finally, maintain awareness of any emerging exploit reports or security advisories related to this CVE.