CVE-2022-48816 is a vulnerability identified in the Linux kernel related to the SUNRPC (Sun Remote Procedure Call) subsystem. The issue arises from a race condition involving the ->sock pointer within the SUNRPC transport structure. Specifically, the ->sock pointer can be asynchronously set to NULL unless the ->recv_mutex mutex is held during sysfs reads. This improper synchronization can lead to a kernel oops (a kernel crash or panic) when sysfs reads occur concurrently with changes to the ->sock pointer. A prior commit (17f09d3f619a) attempted to mitigate this by checking if the transport is connected before handling sysfs reads, but this only reduced the race window rather than fully resolving the issue. The vulnerability affects multiple Linux kernel versions identified by specific commit hashes. Although no known exploits are currently reported in the wild, the flaw could potentially be triggered by local or remote processes that can induce sysfs reads on affected systems, leading to denial of service through kernel crashes. The absence of a CVSS score indicates that the vulnerability is newly published and not yet fully assessed for severity. The root cause is a concurrency control flaw in kernel code managing network transport sockets, which is critical for system stability and security.

For European organizations, the impact of CVE-2022-48816 primarily involves potential denial of service conditions on Linux-based systems that utilize the SUNRPC subsystem, which is common in environments running NFS (Network File System) or other RPC-based services. A kernel oops can cause system instability, crashes, or reboots, disrupting critical services and potentially leading to downtime. This can affect servers, network appliances, and embedded devices running vulnerable Linux kernel versions. Organizations relying on Linux for infrastructure, cloud services, or edge computing could see operational impacts, especially if the vulnerability is triggered repeatedly or exploited in combination with other flaws. While there is no evidence of remote code execution or privilege escalation, the instability caused could be leveraged by attackers to degrade service availability or as part of a larger attack chain. Given the widespread use of Linux in European data centers, telecommunications, and government infrastructure, the vulnerability poses a moderate risk to availability and operational continuity.

To mitigate CVE-2022-48816, European organizations should prioritize applying the official Linux kernel patches that properly enforce the ->recv_mutex mutex during sysfs reads to prevent the race condition. Since the vulnerability relates to kernel-level concurrency, updating to the latest stable kernel versions that include the fix is essential. Organizations should audit their systems to identify affected kernel versions using the provided commit hashes or vendor advisories. For environments where immediate patching is not feasible, consider isolating vulnerable systems from untrusted networks and limiting access to sysfs interfaces, especially restricting unprivileged users from triggering sysfs reads related to SUNRPC. Monitoring kernel logs for oops or crash signatures related to SUNRPC can help detect exploitation attempts. Additionally, implementing robust system and network monitoring to detect unusual RPC or NFS activity may provide early warning. Coordination with Linux distribution vendors for backported patches and security advisories is recommended to ensure timely remediation.