CVE-2024-35889 is a vulnerability identified in the Linux kernel's idpf network driver, which handles packet processing for certain Intel Ethernet devices. The issue arises when the driver encounters an unknown packet type. In such cases, the function idpf_rx_process_skb_fields returns early without invoking eth_type_trans, a critical function responsible for setting the skb (socket buffer) protocol and determining the appropriate network layer handler. This omission leads to improper packet handling. The vulnerability is particularly problematic when diagnostic tools like tcpdump are running and such an unknown packet is received, causing a kernel panic—a severe system crash that results in denial of service. The root cause is that the driver does not call eth_type_trans for every packet, which is necessary even when the packet type is unrecognized. The fix involves ensuring eth_type_trans is called for all packets, preventing the kernel panic by properly setting the protocol and avoiding the crash. This vulnerability affects specific Linux kernel versions identified by the commit hash 3a8845af66edb340ba9210bb8a0da040c7d6e590, and it was publicly disclosed on May 19, 2024. There are no known exploits in the wild at this time, and no CVSS score has been assigned yet.

For European organizations, this vulnerability poses a risk primarily related to system availability and stability. Linux is widely used across European enterprises, government agencies, and critical infrastructure, often running on servers, network appliances, and embedded systems. A kernel panic triggered by this vulnerability could cause unexpected system crashes, leading to denial of service conditions. This can disrupt business operations, especially in environments where network monitoring tools like tcpdump are used for traffic analysis or security monitoring. While the vulnerability does not directly lead to privilege escalation or data leakage, the resulting downtime could impact service availability, incident response, and operational continuity. Organizations relying on affected Linux kernel versions and Intel Ethernet hardware using the idpf driver should be aware of the potential for system instability. Given the lack of known exploits, the immediate risk is moderate, but the vulnerability should be addressed promptly to prevent exploitation as attackers may develop triggers for unknown packet types to induce crashes.

European organizations should take the following specific steps to mitigate this vulnerability: 1) Identify systems running affected Linux kernel versions with the idpf driver active, particularly those using Intel Ethernet devices supported by this driver. 2) Apply the vendor-provided patch or update the Linux kernel to a version that includes the fix ensuring eth_type_trans is called for all packets. 3) In environments where immediate patching is not feasible, consider temporarily disabling or limiting the use of tcpdump or similar packet capture tools on affected systems to reduce the risk of triggering the kernel panic. 4) Implement network filtering to block or limit unknown or malformed packet types that could trigger the vulnerability, especially on perimeter or critical network segments. 5) Monitor system logs and kernel messages for signs of unexpected crashes or packet processing errors that may indicate attempts to exploit this issue. 6) Incorporate this vulnerability into vulnerability management and patching workflows to ensure timely remediation. 7) Engage with Linux distribution vendors and Intel for any additional guidance or updated drivers.