CVE-2024-46832 is a vulnerability identified in the Linux kernel specifically affecting the MIPS architecture, particularly the cevt-r4k timer implementation. The issue arises from the kernel calling the function get_c0_compare_int on secondary CPUs when a timer interrupt request (IRQ) is installed. This leads to a warning and an unstable kernel state indicated by the message: "BUG: sleeping function called from invalid context at kernel/locking/mutex.c:283." The root cause is that get_c0_compare_int is invoked in an inappropriate context on secondary CPUs, which violates kernel locking and sleeping context rules, potentially causing kernel instability or crashes. Additionally, the vulnerability involves improper handling of the IRQ number in the clock_event_device structure, where the IRQ number was saved unnecessarily despite being unused by the clockevent core. The fix involves preventing the call to get_c0_compare_int when a timer IRQ is installed and skipping the unnecessary saving of the IRQ number for non-CPU local devices. This vulnerability is specific to the MIPS architecture and does not affect other architectures. No known exploits are currently reported in the wild, and no CVSS score has been assigned yet. The vulnerability was published on September 27, 2024, and is relevant to Linux kernel versions containing the specified commit hashes. The issue primarily impacts kernel stability and reliability on affected MIPS-based systems, which are often embedded or specialized devices running Linux.

For European organizations, the impact of CVE-2024-46832 depends largely on the deployment of MIPS-based Linux systems within their infrastructure. MIPS architecture is commonly used in embedded systems, network devices, and specialized industrial equipment rather than mainstream servers or desktops. Organizations relying on such devices for critical operations—such as telecommunications providers, industrial automation companies, or IoT device manufacturers—may experience kernel crashes or system instability if the vulnerability is exploited or triggered inadvertently. This could lead to denial of service conditions, impacting availability of critical services or devices. Since the vulnerability involves kernel-level bugs, there is a risk of broader system disruption, but no direct evidence suggests privilege escalation or remote code execution. The absence of known exploits reduces immediate risk, but unpatched systems remain vulnerable to potential future exploitation or accidental crashes. European entities with MIPS-based infrastructure should prioritize patching to maintain operational continuity and avoid service interruptions.

1. Apply the official Linux kernel patches that address CVE-2024-46832 as soon as they become available from trusted sources or Linux distributions supporting MIPS architecture. 2. For organizations using custom or embedded Linux builds, coordinate with vendors or internal development teams to integrate the patch into firmware or kernel updates promptly. 3. Conduct thorough testing of patched kernels in staging environments to ensure stability and compatibility with existing hardware and software. 4. Monitor system logs for kernel warnings or crashes related to timer IRQs or mutex locking to detect potential exploitation or triggering of the vulnerability. 5. Limit access to MIPS-based devices to trusted personnel and networks to reduce risk of accidental or malicious triggering. 6. Maintain an inventory of all MIPS-based Linux systems within the organization to ensure comprehensive patch management coverage. 7. Consider deploying kernel hardening and monitoring tools that can detect anomalous kernel behavior or invalid context calls to preemptively identify issues.