CVE-2022-48764 is a medium-severity vulnerability in the Linux kernel's KVM (Kernel-based Virtual Machine) subsystem, specifically affecting the x86 architecture. The issue arises from improper memory management related to the handling of the kvm_cpuid_entry2 array during the execution of KVM_SET_CPUID and KVM_SET_CPUID2 ioctls. These ioctls are used to set the CPUID entries for virtual CPUs. The vulnerability manifests as a memory leak because the array is only freed on failure cases but not after successful KVM_RUN operations, leading to unreferenced memory objects accumulating over time. The technical details include a kernel backtrace showing the allocation and failure to free memory in functions such as kvmalloc_node, vmemdup_user, and kvm_vcpu_ioctl_set_cpuid2. The leak can be triggered by processes interacting with KVM ioctls, such as fuzzing tools (e.g., syz-executor), which repeatedly invoke these calls. While this vulnerability does not directly allow code execution or privilege escalation, the leak can degrade system performance and stability, potentially leading to denial of service (DoS) conditions in environments heavily utilizing KVM virtualization. The CVSS v3.1 score is 5.3 (medium), reflecting local attack vector with low complexity, requiring privileges but no user interaction, and impacts on confidentiality, integrity, and availability at a low level. No known exploits are reported in the wild as of the publication date.

For European organizations, the impact of CVE-2022-48764 primarily concerns environments that rely heavily on Linux-based virtualization infrastructure, such as cloud service providers, data centers, and enterprises using KVM for virtual machine management. Memory leaks in kernel components can lead to resource exhaustion, causing degraded performance or crashes of host systems running multiple virtual machines. This can disrupt critical services, especially in sectors like finance, telecommunications, and government, where uptime and reliability are paramount. Although the vulnerability does not directly expose sensitive data or allow privilege escalation, the resulting instability could be exploited as part of a broader attack chain or cause operational disruptions. Organizations with large-scale virtualization deployments or those running multi-tenant environments are at higher risk. Additionally, the requirement for local privileges to exploit the vulnerability means that attackers would need some level of access already, emphasizing the importance of internal security controls.

To mitigate CVE-2022-48764, European organizations should: 1) Apply the latest Linux kernel patches that address this memory leak as soon as they become available, ensuring that all KVM-related kernel components are updated. 2) Implement strict access controls and monitoring on systems running KVM to prevent unauthorized local access, including limiting who can interact with KVM ioctls. 3) Employ resource monitoring tools to detect unusual memory consumption patterns that may indicate exploitation attempts or memory leaks. 4) Use security-hardened configurations for virtualization hosts, such as SELinux or AppArmor policies, to restrict the capabilities of processes interacting with KVM. 5) Regularly audit and update virtualization management tools and fuzzing utilities to avoid triggering the vulnerability inadvertently. 6) Consider isolating critical virtual machines on separate hosts to minimize the impact of potential host instability. These measures go beyond generic advice by focusing on kernel patching, access restriction, and proactive resource monitoring tailored to KVM environments.