CVE-2022-48799 is a vulnerability identified in the Linux kernel's performance monitoring subsystem, specifically within the perf_cgroup_switch() function. The issue arises from improper handling of a linked list named cgrp_cpuctx_list during context switches in control groups (cgroups). The vulnerability is due to list corruption caused by unsafe iteration and removal of entries from this list. The problematic code uses list_for_each_entry() to iterate over cgrp_cpuctx_list, but during iteration, entries may be removed by perf_cgroup_event_disable(), leading to corruption of the linked list structure. The root cause is that list_for_each_entry() does not safely handle removal of elements during traversal, which can cause undefined behavior, including memory corruption or kernel crashes. The fix involves replacing list_for_each_entry() with list_for_each_entry_safe(), which safely allows removal of list entries while iterating. This vulnerability affects multiple versions of the Linux kernel identified by the commit hash 058fe1c0440e68a1ba3c2270ae43e9f0298b27d8. Although no known exploits are reported in the wild, the flaw could potentially be triggered by local users or processes with the ability to interact with the perf subsystem and cgroups, leading to denial of service (kernel panic) or possibly privilege escalation if exploited in conjunction with other vulnerabilities. The vulnerability does not require network access but does require local access and interaction with kernel perf events and cgroups. No CVSS score is assigned yet, and no public patches or exploits are currently available, but the issue is recognized and published by the Linux project and CISA.

For European organizations, the impact of CVE-2022-48799 can be significant, especially for those relying heavily on Linux-based infrastructure for servers, cloud environments, and container orchestration platforms that utilize cgroups for resource management. Exploitation could lead to system instability or denial of service through kernel crashes, affecting availability of critical services. In multi-tenant environments such as cloud providers or shared hosting, this vulnerability could be leveraged by a malicious tenant to disrupt other tenants or escalate privileges if combined with other vulnerabilities. The integrity of system operations could be compromised if attackers manipulate kernel data structures. Confidentiality impact is limited as the vulnerability primarily affects kernel data structure integrity and availability rather than direct data leakage. However, disruption of services could indirectly affect business continuity and compliance with European regulations such as GDPR if critical systems are impacted. Given the widespread use of Linux in European government, financial, telecommunications, and industrial sectors, the vulnerability poses a risk to operational resilience and security posture.

European organizations should prioritize updating Linux kernels to versions that include the fix replacing list_for_each_entry() with list_for_each_entry_safe() in the perf_cgroup_switch() function. Since no official patch links are provided, organizations should monitor Linux kernel mailing lists and trusted repositories for the official patch and apply it promptly. In the interim, organizations should restrict access to perf subsystem interfaces and cgroup management to trusted administrators only, minimizing the attack surface. Employ kernel hardening techniques such as enabling Kernel Address Space Layout Randomization (KASLR), Kernel Page Table Isolation (KPTI), and other security modules like SELinux or AppArmor to limit potential exploitation impact. Conduct thorough auditing and monitoring of kernel logs for anomalies related to perf events and cgroup operations. For containerized environments, ensure container runtime and orchestration platforms are updated and configured to limit privileged access to kernel features. Regular vulnerability scanning and penetration testing focusing on local privilege escalation vectors should be conducted to detect potential exploitation attempts.