CVE-2026-74312

In the Linux kernel, the following vulnerability has been resolved:

vhost/vdpa: validate virtqueue index in mmap and fault paths

vhost_vdpa_mmap() and vhost_vdpa_fault() use vma->vm_pgoff as a

virtqueue index for get_vq_notification(), but they do not validate

that the index is smaller than v->nvqs.

The ioctl path already performs both a bounds check and

array_index_nospec(), but the mmap/fault path only checks that the

index fits in u16. This allows an out-of-range queue index to reach

driver-specific get_vq_notification() callbacks.

Fix this by extracting a unified vhost_vdpa_get_vq_notification()

helper that validates the queue index against v->nvqs and applies

array_index_nospec() before calling the driver callback. Both the

mmap and fault paths use this helper, and the bounds checking is

consolidated into a single location.

From source inspection, the most defensible impact is out-of-bounds

access in the callback path, potentially leading to invalid PFN

remaps and crash/DoS.