CVE-2025-38283 in Linux
Summary
by MITRE • 07/10/2025
In the Linux kernel, the following vulnerability has been resolved:
hisi_acc_vfio_pci: bugfix live migration function without VF device driver
If the VF device driver is not loaded in the Guest OS and we attempt to perform device data migration, the address of the migrated data will be NULL. The live migration recovery operation on the destination side will access a null address value, which will cause access errors.
Therefore, live migration of VMs without added VF device drivers does not require device data migration. In addition, when the queue address data obtained by the destination is empty, device queue recovery processing will not be performed.
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Analysis
by VulDB Data Team • 12/07/2025
The vulnerability described in CVE-2025-38283 resides within the Linux kernel's hisi_acc_vfio_pci driver, specifically affecting the live migration functionality of virtual machines. This issue manifests when attempting to migrate virtual machines that utilize virtual functions (VFs) without the corresponding device driver being loaded in the guest operating system. The root cause stems from improper handling of device data migration processes where the system fails to validate the presence of required driver components before proceeding with migration operations. The vulnerability represents a classic case of null pointer dereference that occurs during device state recovery operations, creating a critical failure point in virtualization environments. This flaw directly impacts the reliability and stability of live migration processes in virtualized infrastructure, particularly in data center environments where seamless VM migration is essential for maintaining service availability.
The technical implementation of this vulnerability involves the VFIO (Virtual Function I/O) PCI subsystem within the hisi_acc_vfio_pci driver, which manages the communication between virtual machines and hardware devices. During live migration operations, the system attempts to transfer device data from the source to the destination host, but when the VF device driver is absent from the guest OS, the migration process fails to properly initialize the device address structures. This results in NULL pointer values being passed to the destination side's recovery mechanisms, causing kernel-level access violations and potential system crashes. The flaw specifically affects the queue address handling logic where empty or uninitialized queue structures are processed without proper validation, leading to invalid memory access patterns. According to CWE classification, this vulnerability maps to CWE-476_NULL_Pointer_Dereference, representing a fundamental error in pointer validation and memory management within kernel space operations. The issue demonstrates poor defensive programming practices in handling edge cases where expected device drivers are not present during migration scenarios.
The operational impact of this vulnerability extends beyond simple migration failures to potentially compromise entire virtualization platforms, particularly in enterprise environments where live migration is a core infrastructure requirement. When VMs without VF device drivers attempt migration, the system experiences complete failure of the migration process, resulting in service disruption and potential data loss. The vulnerability affects critical virtualization workflows including disaster recovery operations, load balancing scenarios, and maintenance activities that depend on seamless VM movement across hosts. In production environments, this could lead to significant downtime costs and service level agreement violations. From an ATT&CK framework perspective, this vulnerability could be leveraged by adversaries to disrupt virtualization services, potentially enabling denial-of-service conditions that affect multiple VMs simultaneously. The impact is particularly severe in cloud computing environments where hypervisor-level vulnerabilities can affect tenant isolation and overall platform stability, making this a critical security concern for infrastructure providers.
Mitigation strategies for this vulnerability should focus on both immediate operational fixes and long-term architectural improvements. The primary solution involves implementing proper validation checks within the hisi_acc_vfio_pci driver to ensure that device data migration only proceeds when appropriate driver components are present in the guest OS. This includes adding pre-migration verification routines that check for VF device driver availability and gracefully handling cases where such drivers are missing. System administrators should implement monitoring solutions to detect migration failures and automatically trigger recovery procedures or alert administrators to investigate. The kernel patch should include enhanced error handling that prevents NULL pointer dereferences by implementing proper null checks before accessing device address structures. Additionally, organizations should consider implementing migration policies that require specific driver configurations before allowing live migration operations, particularly for hardware-accelerated virtualization environments. Regular kernel updates and security patches should be prioritized to address this class of vulnerability, as it represents a fundamental flaw in device management during virtualization operations that could be exploited to cause system instability or service disruption.