CVE-2022-49456 is a vulnerability identified in the Linux kernel's bonding driver, specifically related to the function bond_ethtool_get_ts_info(). The issue arises from a missing Read-Copy-Update (RCU) protection when this function is called via the setsockopt system call, which does not hold the RCU lock. The bonding driver aggregates multiple network interfaces into a single logical interface for redundancy or increased throughput. The vulnerability was introduced when the rcu_read_lock was removed from bond_ethtool_get_ts_info(), without recognizing that this function could be invoked through setsockopt without the necessary RCU lock held. This omission can lead to unsafe concurrent access to shared data structures, potentially causing use-after-free or data corruption scenarios. The kernel stack trace provided shows the call path leading to the vulnerability, highlighting that the setsockopt syscall invokes bond_ethtool_get_ts_info() without proper synchronization. The fix involves re-adding the rcu_read_lock and taking a reference on the real_dev device structure to ensure safe access. Since dev_hold() and dev_put() can now handle NULL pointers, the fix simplifies the check for the existence of real_dev. This vulnerability affects Linux kernel versions containing the specified commit hashes and is relevant to systems using the bonding driver for network interface aggregation. No known exploits are reported in the wild, and no CVSS score has been assigned yet.

For European organizations, the impact of CVE-2022-49456 depends largely on their deployment of Linux systems utilizing the bonding driver for network interface aggregation. Bonding is commonly used in enterprise environments to enhance network reliability and performance. Exploitation of this vulnerability could lead to kernel memory corruption, potentially causing system instability, crashes, or privilege escalation if an attacker can manipulate the bonding interface via setsockopt calls. This could disrupt critical network services, affecting availability and potentially confidentiality and integrity if attackers gain elevated privileges. Given that Linux is widely used in European data centers, cloud infrastructures, and enterprise servers, organizations relying on bonded network interfaces may face operational risks. However, exploitation requires local or remote code execution capabilities to invoke setsockopt with crafted parameters, which may limit the attack surface. The absence of known exploits suggests the threat is currently theoretical but warrants proactive mitigation to prevent future attacks. Disruptions in network bonding could impact sectors such as finance, telecommunications, and government services, where high network availability is essential.

European organizations should prioritize updating their Linux kernels to versions that include the patch fixing CVE-2022-49456. Specifically, they should apply the kernel updates that reintroduce the rcu_read_lock protection in bond_ethtool_get_ts_info() and ensure proper reference counting on real_dev. System administrators should audit their environments to identify systems using the bonding driver and verify kernel versions. For environments where immediate patching is not feasible, consider restricting access to setsockopt system calls related to network interfaces via mandatory access controls (e.g., SELinux, AppArmor) or seccomp filters to limit potential exploitation. Network segmentation and strict user privilege management can reduce the risk of unauthorized invocation of vulnerable calls. Monitoring kernel logs for unusual bonding driver activity and implementing intrusion detection systems that can flag anomalous setsockopt usage may help detect exploitation attempts. Additionally, organizations should maintain an inventory of Linux kernel versions and bonding configurations to facilitate rapid response to emerging threats.