CVE-2022-48930 is a vulnerability identified in the Linux kernel specifically related to the RDMA (Remote Direct Memory Access) subsystem, within the ib_srp (SCSI RDMA Protocol) driver. The issue arises from a deadlock condition caused by the use of the flush_workqueue(system_long_wq) call. This call was found to be deadlock-prone and redundant because it overlaps with a preceding cancel_work_sync() call. The deadlock occurs when the system attempts to flush the system_long_wq workqueue, potentially causing kernel threads to wait indefinitely, leading to system hangs or degraded performance. The vulnerability has been addressed by removing the problematic flush_workqueue call, thereby preventing the deadlock scenario. This fix improves kernel stability and reliability when handling RDMA operations via the ib_srp driver. The vulnerability affects Linux kernel versions identified by the commit hash ef6c49d87c3418c442a22e55e3ce2f91b163d69e, which suggests a specific patch or kernel tree state. No known exploits are currently reported in the wild, and no CVSS score has been assigned yet. The nature of the vulnerability is a kernel-level deadlock, which primarily impacts system availability rather than confidentiality or integrity. Exploitation would likely require local access or the ability to trigger RDMA operations that invoke the ib_srp driver code paths. This vulnerability is significant for environments relying on RDMA for high-performance networking and storage, such as data centers and HPC clusters running Linux kernels with the affected code.

For European organizations, the impact of CVE-2022-48930 centers on system availability and stability, especially in sectors utilizing RDMA-enabled Linux servers. These include financial institutions, research centers, cloud service providers, and telecommunications companies that depend on low-latency, high-throughput networking for critical workloads. A deadlock in the kernel can cause system hangs or crashes, leading to downtime, disruption of services, and potential data loss if systems become unresponsive. While this vulnerability does not directly compromise data confidentiality or integrity, the availability impact can affect business continuity and operational efficiency. Organizations with large-scale Linux deployments or those using RDMA for storage or network acceleration are at higher risk. Given the absence of known exploits, the immediate threat level is moderate; however, unpatched systems remain vulnerable to accidental or deliberate triggering of the deadlock condition. This could be exploited by insiders or attackers with local access to degrade system performance or cause denial of service. The vulnerability also poses a risk to cloud providers and managed service providers in Europe, where multi-tenant environments rely on stable kernel operations to ensure service level agreements (SLAs).

European organizations should prioritize updating their Linux kernels to versions that include the fix for CVE-2022-48930. Specifically, they should apply the patch that removes the flush_workqueue(system_long_wq) call in the ib_srp driver. Kernel updates should be tested in staging environments to ensure compatibility with existing RDMA workloads. Additionally, organizations should audit their use of RDMA and ib_srp to identify systems that might be affected. For environments where immediate patching is not feasible, temporarily disabling or limiting RDMA functionality related to ib_srp can reduce exposure. Monitoring system logs and kernel messages for signs of deadlock or hangs related to workqueue flushing can help detect attempts to trigger the vulnerability. Implementing strict access controls to limit who can execute RDMA operations or load kernel modules can reduce the risk of exploitation. Finally, organizations should maintain robust backup and recovery procedures to mitigate the impact of potential system outages caused by this vulnerability.