CVE-2025-38158 in Linux
Summary
by MITRE • 07/03/2025
In the Linux kernel, the following vulnerability has been resolved:
hisi_acc_vfio_pci: fix XQE dma address error
The dma addresses of EQE and AEQE are wrong after migration and results in guest kernel-mode encryption services failure. Comparing the definition of hardware registers, we found that there was an error when the data read from the register was combined into an address. Therefore, the address combination sequence needs to be corrected.
Even after fixing the above problem, we still have an issue where the Guest from an old kernel can get migrated to new kernel and may result in wrong data.
In order to ensure that the address is correct after migration, if an old magic number is detected, the dma address needs to be updated.
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Analysis
by VulDB Data Team • 04/18/2026
The vulnerability CVE-2025-38158 represents a critical DMA address error in the Hisilicon acceleration driver within the Linux kernel, specifically affecting the hisi_acc_vfio_pci module. This flaw manifests as incorrect DMA addresses for Event Queue Entries (EQE) and Asynchronous Event Queue Entries (AEQE) following virtual machine migration operations, leading to complete failure of guest kernel-mode encryption services. The issue stems from improper data combination when reading hardware register values to construct DMA addresses, creating a fundamental architectural flaw in the address formation logic. This vulnerability directly impacts virtualized environments where hardware acceleration is utilized, particularly in scenarios involving live migration between different kernel versions.
The technical implementation of this vulnerability involves a specific error in how hardware register values are processed to generate DMA addresses for queue entries. According to CWE-681, this represents an incorrect conversion between data types or improper handling of bit manipulation operations during address construction. The flaw occurs when the driver reads register values that contain the lower and upper portions of DMA addresses, but the subsequent combination logic fails to properly assemble these components, resulting in invalid memory addresses. This type of error falls under the category of improper bit manipulation and address formation, which is classified as CWE-784 in the CWE database, indicating an improper control of a resource through another control.
The operational impact of this vulnerability extends beyond simple functionality failure to encompass complete service disruption in virtualized encryption environments. When guest virtual machines undergo migration from older kernel versions to newer ones, the system fails to properly update the DMA addresses, leading to data corruption and service failures. This creates a particularly dangerous scenario where the migration process itself becomes a vector for introducing incorrect memory references. The vulnerability affects the integrity of hardware-assisted encryption services, which are critical for secure data processing in virtualized environments. According to ATT&CK framework technique T1553.006, this represents an improper handling of system resources during migration operations, potentially enabling attackers to manipulate memory access patterns and compromise encryption integrity.
The mitigation strategy requires implementing detection and correction mechanisms for legacy migration scenarios. When the driver detects an old magic number indicating migration from an older kernel version, it must automatically update the DMA addresses to ensure proper memory mapping. This approach addresses the compatibility issue between different kernel versions while maintaining the integrity of the hardware acceleration framework. The fix must be implemented at the VFIO PCI driver level to ensure that all migration paths properly handle DMA address validation. Additionally, the solution should include runtime validation of DMA addresses and automatic correction mechanisms to prevent the propagation of incorrect memory references throughout the system. The vulnerability demonstrates the complexity of maintaining compatibility in virtualized environments while ensuring proper resource management and memory integrity across kernel version boundaries.