CVE-2024-39461 is a vulnerability identified in the Linux kernel specifically affecting the Broadcom (bcm) clock driver for Raspberry Pi devices. The issue arises from improper initialization order in the code within the function raspberrypi_discover_clocks(). The vulnerability is related to the handling of the struct clk_hw_onecell_data, which contains an array member 'hws' annotated with __counted_by to indicate the number of elements for bounds checking by the Undefined Behavior Sanitizer (UBSAN). The problem occurs because the 'num' field, which specifies the number of elements in the 'hws' array, is assigned after the array is accessed. This leads to out-of-bounds array access warnings from UBSAN, indicating a potential for accessing invalid memory locations. The root cause is that the bounds sanitizer expects the 'num' field to be initialized before any access to 'hws' to correctly enforce array bounds. The fix involves moving the assignment of 'num' to before the first access of 'hws', thereby preventing out-of-bounds access and eliminating the UBSAN warnings. Although this vulnerability is primarily a code correctness and memory safety issue detected by a sanitizer, it could potentially lead to undefined behavior if exploited, such as memory corruption or crashes. However, there is no indication of known exploits in the wild, and the vulnerability appears to be limited to the Raspberry Pi clock driver within the Linux kernel. The affected versions are identified by a specific commit hash, and the issue was published on June 25, 2024. No CVSS score has been assigned yet.

For European organizations, the impact of CVE-2024-39461 is likely limited but should not be disregarded. The vulnerability affects the Linux kernel's Raspberry Pi clock driver, which is relevant primarily to environments using Raspberry Pi devices running affected Linux kernel versions. Organizations using Raspberry Pi for IoT deployments, edge computing, or development platforms could experience stability issues such as kernel crashes or undefined behavior due to out-of-bounds memory access. While no active exploitation is known, the potential for memory corruption could be leveraged in targeted attacks to escalate privileges or cause denial of service if combined with other vulnerabilities. The impact on confidentiality, integrity, and availability is therefore medium to low in isolation but could be higher in complex attack chains. Given the widespread use of Linux in European enterprises and research institutions, especially in embedded systems and IoT, awareness and patching are important to maintain system reliability and security.

To mitigate CVE-2024-39461, European organizations should: 1) Identify and inventory all Raspberry Pi devices running affected Linux kernel versions, especially those used in production or critical environments. 2) Apply the patch that reorders the initialization of the 'num' field before accessing the 'hws' array as soon as it becomes available in the Linux kernel updates or backported fixes from trusted sources. 3) For environments where immediate patching is not feasible, implement monitoring for kernel crashes or unusual behavior on Raspberry Pi devices that could indicate exploitation attempts or instability. 4) Employ kernel hardening techniques such as enabling kernel address space layout randomization (KASLR), stack canaries, and other memory protection features to reduce the risk of exploitation. 5) Maintain strict access controls and limit network exposure of Raspberry Pi devices to reduce attack surface. 6) Engage with Linux kernel maintainers or vendors for timely updates and verify that custom kernel builds incorporate the fix. 7) Conduct thorough testing of patched kernels in staging environments before deployment to avoid regressions.