CVE-2022-48905 in Linux
Summary
by MITRE • 08/22/2024
In the Linux kernel, the following vulnerability has been resolved:
ibmvnic: free reset-work-item when flushing
Fix a tiny memory leak when flushing the reset work queue.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 09/13/2024
The vulnerability identified as CVE-2022-48905 resides within the linux kernel's ibmvnic driver component which manages IBM PowerVM virtual network interfaces. This issue represents a subtle memory management flaw that occurs during the operation of the reset work queue flushing mechanism. The ibmvnic driver operates within the hypervisor environment of IBM PowerVM systems, handling network communication between virtual machines and physical network infrastructure. When system administrators or automated processes initiate the flushing of reset work items, the driver fails to properly release allocated memory resources, resulting in a memory leak that accumulates over time.
The technical flaw manifests in the improper handling of work queue cleanup operations within the ibmvnic subsystem. Specifically, when the driver executes the flush operation on the reset work queue, it successfully processes the work items but neglects to free the associated memory structures that were allocated for these work items. This memory leak occurs in the context of kernel memory management where allocated kernel memory blocks are not returned to the system's memory pool. The vulnerability is classified as a memory leak under CWE-401, which specifically addresses improper management of memory resources in software applications. The flaw exists in the driver's cleanup routine where the work item structures remain allocated in kernel memory, creating a gradual degradation of available system resources.
The operational impact of this memory leak, while initially appearing minor, can accumulate over extended periods of system operation, particularly in high-availability environments where the ibmvnic driver experiences frequent reset operations. As the memory leak compounds, it can lead to gradual system performance degradation, increased memory pressure, and potentially contribute to system instability or resource exhaustion scenarios. The vulnerability affects systems running affected kernel versions where the ibmvnic driver is actively managing virtual network interfaces, particularly in IBM PowerVM environments where virtual machine migrations or network configuration changes trigger the reset work queue operations. This issue is particularly concerning in enterprise environments where system uptime and resource utilization are critical factors for operational reliability and performance management.
Mitigation strategies for this vulnerability focus on applying the kernel patch that resolves the memory leak in the ibmvnic driver's reset work queue handling. System administrators should prioritize updating their kernel versions to include the fix that properly implements memory cleanup when flushing reset work items. The fix ensures that all allocated memory structures associated with reset work items are properly freed during the flush operation, maintaining proper kernel memory management practices. Organizations should conduct regular kernel updates and security assessments to ensure their systems remain protected against similar memory management vulnerabilities. The remediation process should include thorough testing of the updated kernel in controlled environments before deployment to production systems to verify that the fix does not introduce compatibility issues with existing network configurations or virtualization workloads. Additionally, monitoring systems should be implemented to track memory utilization patterns and identify potential memory leak accumulation that could indicate similar issues in other kernel components. This vulnerability demonstrates the importance of proper resource management in kernel space operations and aligns with ATT&CK technique T1070.004 related to indicator removal on host through memory clearing operations.