CVE-2026-74520
HighCVSS 8.8Exploitation Probability (EPSS)
Low risk3th percentile - higher than 3% of all known CVEs
Summary
In the Linux kernel's iommu/iommufd subsystem, a use-after-free vulnerability was found in IOPF group ownership. IOPF groups are linked into the generic pending list before invoking the domain fault handler, and after acceptance they are also queued in the IOMMUFD deliver list without removal from the generic list. When detach or HWPT replacement drops the device's IOPF reference count to zero, groups can be freed, and later access leads to UAF.
Risk Assessment
The vulnerability can lead to kernel crash or potential code execution in kernel context, posing a serious threat to system security.
Recommendation
Apply the kernel patch that dequeues an accepted group from the generic pending list before IOMMUFD queues it for userspace response. Update the system to a kernel version containing this fix.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: iommu/iommufd: Fix IOPF group ownership UAF iopf_group_alloc() links each last-page IOPF group into the generic IOPF pending list before invoking the domain fault handler. iommufd_fault_iopf_handler() also queued an accepted group in the IOMMUFD deliver list without removing it from the generic pending list. When detach or HWPT replacement drops the device's IOPF reference count to zero, an IOMMU driver may call iopf_queue_remove_device(). That function responds to and frees groups through the generic pending list without removing the same groups from IOMMUFD's deliver list or response xarray. A later read, response, or cleanup can then access the freed group and cause a UAF. Fix this by dequeuing an accepted group from the generic pending list before IOMMUFD queues it for userspace response. Make iopf_group_response() send a response regardless of pending-list membership, so the dequeued group can still be completed by IOMMUFD.