CVE-2024-27038 is a vulnerability identified in the Linux kernel's clock framework, specifically within the clk_core_get() function. The vulnerability arises due to a NULL pointer dereference caused by improper handling of the return value from the __clk_get_hw() function. In the affected code path, __clk_get_hw() can return NULL, but clk_core_get() proceeds to dereference the returned pointer without verifying its validity, leading to a potential NULL pointer dereference at hw->core. This issue was introduced after a commit (dde4eff47c82) that removed a previous check (IS_ERR_OR_NULL()) which would have caught NULL returns. The vulnerability can cause kernel crashes or system instability when clk_core_get() is invoked with certain clock specifications that lead to NULL hardware clock references. The fix involves reintroducing a check for NULL before dereferencing the pointer and returning NULL if the hardware clock pointer is invalid. This vulnerability affects Linux kernel versions containing the specified commit and potentially other versions derived from it. No known exploits are currently reported in the wild, and no CVSS score has been assigned yet. The vulnerability is a classic example of improper pointer validation in kernel code, which can lead to denial of service through kernel panics or crashes.

For European organizations, the impact of CVE-2024-27038 primarily involves potential denial of service (DoS) conditions on Linux-based systems. Since the Linux kernel is widely used across servers, embedded devices, and critical infrastructure, a kernel panic or crash caused by this vulnerability could disrupt business operations, especially in environments relying on specific hardware clock configurations. This could affect data centers, cloud service providers, telecommunications infrastructure, and industrial control systems that run Linux kernels with the affected code. While the vulnerability does not directly lead to privilege escalation or remote code execution, the resulting instability could be exploited as part of a broader attack chain or cause significant operational downtime. Systems that handle real-time processing or require high availability could be particularly vulnerable to service interruptions. The absence of known exploits reduces immediate risk, but the vulnerability's presence in the kernel code base means that attackers with local access or the ability to influence clock configuration could trigger crashes. For organizations in Europe, especially those in sectors such as finance, healthcare, and critical infrastructure, ensuring kernel stability is crucial to maintaining compliance with regulatory requirements and operational resilience.

To mitigate CVE-2024-27038, European organizations should prioritize updating their Linux kernels to versions where the patch addressing this NULL pointer dereference has been applied. This involves tracking vendor-specific kernel updates or mainline Linux kernel releases that include the fix. For environments using custom or embedded Linux kernels, developers should backport the patch to their kernel versions. Additionally, organizations should audit systems to identify any software or drivers that interact with the clock framework and verify that they do not pass malformed or unexpected clock specifications that could trigger the vulnerability. Implementing kernel crash monitoring and alerting can help detect exploitation attempts or instability early. In environments where immediate patching is not feasible, restricting local access and limiting the ability of unprivileged users to invoke clock-related kernel interfaces can reduce risk. Finally, maintaining robust backup and recovery procedures will help minimize downtime if a crash occurs due to this vulnerability.