CVE-2022-49662 is a vulnerability identified in the Linux kernel, specifically within the IPv6 networking stack. The issue arises from improper usage of Read-Copy-Update (RCU) synchronization primitives in the function in6_dump_addrs(), which is responsible for dumping IPv6 addresses. The vulnerability was reported by syzbot, an automated kernel fuzzer, which detected suspicious RCU usage where rcu_dereference() is called without holding the required rcu_read_lock(). This incorrect synchronization can lead to race conditions and potential kernel instability or crashes. The detailed technical description indicates that the problem occurs in the addrconf.c source file, with a suspicious rcu_dereference_check() usage at line 5175. The stack trace shows that the issue manifests during netlink socket operations, particularly when dumping network addresses via rtnetlink messages. The root cause is the violation of RCU usage rules, which can cause lock dependency errors (lockdep splat) and potentially lead to kernel panics or denial of service. Although no known exploits are currently reported in the wild, the vulnerability affects Linux kernel versions identified by specific commit hashes, implying it is present in recent or development kernel releases. No CVSS score has been assigned yet, and no patches or mitigations are linked in the provided data, but the issue is recognized and published as a security vulnerability.

For European organizations, the impact of CVE-2022-49662 can be significant, especially for those relying on Linux-based infrastructure for critical networking and server operations. The vulnerability affects the IPv6 stack, which is increasingly important as IPv6 adoption grows across Europe. Exploitation could lead to kernel crashes or denial of service conditions, disrupting network services, cloud environments, and containerized applications running on vulnerable Linux kernels. This could impact availability of services, leading to operational downtime and potential financial losses. While there is no evidence of privilege escalation or remote code execution directly from this vulnerability, the instability caused by improper RCU usage can be leveraged in complex attack chains or targeted denial of service attacks. Organizations with large-scale deployments of Linux servers, especially those using custom or development kernel versions, are at higher risk. The lack of known exploits suggests that the threat is currently low but could increase once exploit techniques mature or if attackers discover ways to trigger the flaw remotely via network interactions.

To mitigate CVE-2022-49662, European organizations should prioritize updating their Linux kernels to versions where this vulnerability is fixed. Since the vulnerability is related to kernel code, applying vendor-supplied kernel patches or upgrading to stable kernel releases that include the fix is the most effective measure. Organizations should monitor Linux kernel mailing lists and official repositories for patch announcements related to this issue. Additionally, auditing and restricting access to systems running vulnerable kernels can reduce exposure. Network segmentation and limiting access to netlink interfaces can help mitigate exploitation risks. For environments using custom or development kernels, thorough testing and code review of networking components, especially those involving RCU usage, are recommended. Employing kernel hardening techniques and runtime protections such as Kernel Address Sanitizer (KASAN) or lockdep can help detect similar issues proactively. Finally, organizations should maintain robust monitoring to detect unusual kernel crashes or network disruptions that could indicate exploitation attempts.