CVE-2022-49814 is a concurrency vulnerability in the Linux kernel's KCM (Kernel Connection Multiplexor) socket implementation. The issue arises from race conditions on the sk_receive_queue, a socket buffer queue used to manage incoming network packets. While the sk_receive_queue is protected by the skb queue lock, KCM sockets use an additional lock, mux->rx_lock, to protect more than just the skb queue in their receive (RX) path. However, the function kcm_recvmsg() only acquires the skb queue lock and does not acquire mux->rx_lock, leaving a window for race conditions. This can lead to inconsistent or corrupted state in the socket receive queue, potentially causing data corruption or unexpected behavior in applications relying on KCM sockets. The Linux kernel developers addressed this by enforcing the skb queue lock in the requeue_rx_msgs() function and carefully handling skb peek cases in kcm_wait_data(). They also replaced the locking in kcm_recvmsg() and kcm_splice_read() with calls to skb_recv_datagram(), which is widely used and handles locking correctly. Additionally, checks for SOCK_DONE, which are not used by KCM sockets, were removed to streamline the code. The fix avoids acquiring mux->rx_lock in kcm_recvmsg() to prevent performance regressions since the kcm_mux structure can be shared by multiple sockets. The vulnerability does not appear to have known exploits in the wild, and the original syzbot reproducer test ran for 30 minutes without issues after the fix. No CVSS score has been assigned yet, and no patch links are provided in the data.

For European organizations, this vulnerability primarily affects systems running Linux kernels with the vulnerable KCM socket implementation. KCM sockets are used for multiplexing multiple connections over a single socket, which can be relevant in high-performance networking applications, container networking, or specialized communication stacks. Exploitation of this race condition could lead to data corruption, denial of service (through socket malfunction or kernel instability), or potentially privilege escalation if an attacker can manipulate socket states. While no known exploits exist currently, the vulnerability could be leveraged in targeted attacks against critical infrastructure or enterprise environments that rely on Linux-based networking stacks. The impact is more pronounced in environments with high network throughput or complex socket multiplexing, such as telecom providers, cloud service providers, and data centers prevalent in Europe. Disruption or compromise of such systems could affect confidentiality and availability of network communications, impacting business operations and services.

European organizations should prioritize updating their Linux kernel versions to include the fix for CVE-2022-49814 once available from their Linux distribution vendors. Since no direct patch links are provided, monitoring official Linux kernel mailing lists and vendor advisories (e.g., Debian, Ubuntu, Red Hat, SUSE) is critical. In the interim, organizations should audit the use of KCM sockets in their environments and consider disabling or limiting their use if feasible. Network administrators should implement strict access controls and monitoring on systems that handle high volumes of socket multiplexing to detect anomalous behavior. Additionally, employing kernel hardening techniques such as Kernel Address Space Layout Randomization (KASLR) and Control Flow Integrity (CFI) can reduce exploitation risk. For environments using container orchestration or virtualization, ensuring that host kernels are patched and container runtimes do not expose vulnerable kernel interfaces is essential. Finally, organizations should incorporate this vulnerability into their vulnerability management and incident response plans to quickly address any emerging exploits.