CVE-2026-74312

Technical Description

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.

Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

References