CVE-2026-74312vhost/vdpa: validate virtqueue index in mmap and fault paths

Official 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.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/0f310bac6db9bd3bb1655707d692d9d2a86eeb17
• https://git.kernel.org/stable/c/4bf5a51963ff816f7443702dc536b9327cf5e550
• https://git.kernel.org/stable/c/55a644031e610ea93fbde2702c7b8f267476552f
• https://git.kernel.org/stable/c/2b3f79b90b231a682315fe2191bb71925650e183
• https://git.kernel.org/stable/c/bbba4f92515238d76018e9b75e41b16d83df52c8
• https://git.kernel.org/stable/c/1f5f94c6c6b2e4eaa5b45815509e21d0c6cfa81e
• https://git.kernel.org/stable/c/32ac9097aa2463fcfc12f61cc4a9ebc3579cba7d
• https://git.kernel.org/stable/c/929e4f044621c8cc30b612fb74e1410bef09e41b