CVE-2024-27047 is a vulnerability identified in the Linux kernel's PHY (physical layer) network driver subsystem. Specifically, the issue arises in the function phy_get_internal_delay, which is responsible for retrieving internal delay parameters related to physical network interfaces. The vulnerability occurs when this function attempts to access an empty array due to improper handling of delay values. This situation can happen if the driver calls phy_get_internal_delay without defining the delay_values array, or if the device-tree properties rx-internal-delay-ps or tx-internal-delay-ps are set to zero. Under these conditions, the function tries to dereference a NULL pointer, leading to a kernel oops—a critical error that causes the kernel to crash or become unstable. The root cause is the absence of a check for the array size being zero before accessing it. The fix involves adding a condition to verify that the size of the delay_values array is not zero before accessing it, preventing the NULL pointer dereference and subsequent kernel crash. This vulnerability is a denial-of-service (DoS) type, as it can cause system instability or crash when triggered. It does not appear to allow privilege escalation or arbitrary code execution. No known exploits are currently reported in the wild. The vulnerability affects certain versions of the Linux kernel identified by specific commit hashes, indicating it is relevant to systems running these kernel versions or derivatives thereof. Since the Linux kernel is widely used across many distributions and devices, the impact can be broad depending on deployment scenarios.

For European organizations, the impact of CVE-2024-27047 primarily concerns system availability and stability. Systems running vulnerable Linux kernel versions with affected PHY drivers may experience kernel crashes or reboots if the vulnerability is triggered, potentially disrupting network connectivity and critical services. This can affect servers, network appliances, embedded devices, and IoT infrastructure that rely on Linux-based systems with PHY drivers configured via device trees. In sectors such as telecommunications, manufacturing, critical infrastructure, and cloud service providers, such disruptions could lead to operational downtime, loss of productivity, and increased incident response costs. Although this vulnerability does not directly compromise confidentiality or integrity, the denial-of-service impact could be leveraged as part of a broader attack chain to degrade service or cause outages. The absence of known exploits reduces immediate risk, but unpatched systems remain vulnerable to accidental or targeted triggering of the kernel oops. Organizations with large Linux deployments, especially those using custom or embedded Linux kernels, should be particularly vigilant.

To mitigate CVE-2024-27047, European organizations should: 1) Identify all Linux systems running affected kernel versions or custom kernels derived from these commits, focusing on those using PHY drivers with device-tree configurations for internal delays. 2) Apply the official Linux kernel patches or updates that include the fix for this vulnerability as soon as they become available from trusted Linux distribution vendors or kernel maintainers. 3) For embedded or custom Linux environments, coordinate with device manufacturers or internal development teams to integrate the patch into firmware or kernel builds. 4) Implement monitoring for kernel oops or unexpected reboots related to network drivers to detect potential exploitation or accidental triggering. 5) Conduct configuration reviews of device-tree parameters (rx-internal-delay-ps and tx-internal-delay-ps) to ensure they are not set to zero or left undefined in a way that could trigger the vulnerability. 6) Employ network segmentation and access controls to limit exposure of vulnerable systems to untrusted networks, reducing the risk of remote triggering. 7) Maintain an incident response plan that includes procedures for handling Linux kernel crashes and service disruptions. These steps go beyond generic patching advice by emphasizing configuration audits, monitoring, and tailored response strategies for affected Linux PHY drivers.