CVE-2022-48840 is a vulnerability in the Linux kernel affecting the iavf network driver, which is used for Intel Ethernet Virtual Function (VF) devices. The issue arises from a recent code change that introduced a wait-loop in the iavf_remove() function to ensure port initialization completes before unregistering the network device. However, this change causes a regression during system reboot or shutdown. Specifically, the iavf_shutdown() callback detaches the device and sets its state to __IAVF_REMOVE. Subsequently, the shutdown callback of the associated Physical Function (PF) driver (such as ice_shutdown) calls sriov_disable(), which indirectly calls iavf_remove(). Because the adapter state is already __IAVF_REMOVE, the wait-loop in iavf_remove() becomes infinite, causing the shutdown or reboot process to hang indefinitely. The vulnerability is triggered when a VF is created on a PF driven by the ice or i40e driver, the VF is bound to the iavf driver, and the system is rebooted. This leads to a blocked shutdown sequence, as demonstrated by kernel stack traces showing the system stuck in the wait-loop. The root cause is a missing state check at the start of iavf_remove() to skip processing if the adapter is already in the remove state. The patch fixes this by adding this state check, preventing the infinite loop during shutdown. This vulnerability affects specific Linux kernel versions containing the problematic commits and impacts systems using Intel Ethernet VF devices with the iavf driver in conjunction with PF drivers like ice or i40e. While no known exploits are reported in the wild, the issue can cause denial of service by hanging system reboot or shutdown operations.

For European organizations, this vulnerability can have significant operational impacts, especially in data centers, cloud providers, and enterprises relying on Linux servers with Intel Ethernet VF devices for virtualization and network performance. A hung shutdown or reboot can delay critical maintenance, patching, or recovery operations, potentially leading to extended downtime. This is particularly problematic for environments requiring high availability or rapid failover. Additionally, automated orchestration systems that rely on clean shutdowns may fail, causing cascading service disruptions. Although this vulnerability does not directly lead to data breaches or privilege escalation, the denial of service effect can impact business continuity and service level agreements (SLAs). Organizations using virtualized network functions or NFV infrastructure with affected drivers are at higher risk. The issue is less likely to be exploited remotely but can be triggered by local administrative actions or automated reboot sequences, making insider threat or misconfiguration scenarios relevant.

European organizations should promptly update their Linux kernels to versions that include the patch fixing CVE-2022-48840. Specifically, ensure that kernel versions incorporate the fix that adds the adapter state check in iavf_remove(). For environments where immediate patching is not feasible, consider the following mitigations: avoid creating VFs bound to the iavf driver on PFs managed by ice or i40e drivers, or disable SR-IOV features temporarily to prevent triggering the shutdown hang. Additionally, implement monitoring to detect hung shutdown or reboot processes and establish manual recovery procedures to handle such scenarios. Testing shutdown and reboot sequences in staging environments before production deployment can help identify if systems are affected. Coordination with hardware and OS vendors to confirm driver versions and patches is recommended. Finally, maintain strict change management and limit administrative access to reduce accidental triggering of the vulnerability.