---
id: CVE-2026-74312
title: 'vhost/vdpa: validate virtqueue index in mmap and fault paths'
summary: |-
  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(),…
severity: high
cvss: 7.8
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
cvssSource: cna
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= ddd89d0a059d8e9740c75a97e0efe9bf07ee51f9 <
    0f310bac6db9bd3bb1655707d692d9d2a86eeb17
  - >-
    Linux >= ddd89d0a059d8e9740c75a97e0efe9bf07ee51f9 <
    4bf5a51963ff816f7443702dc536b9327cf5e550
  - >-
    Linux >= ddd89d0a059d8e9740c75a97e0efe9bf07ee51f9 <
    55a644031e610ea93fbde2702c7b8f267476552f
  - >-
    Linux >= ddd89d0a059d8e9740c75a97e0efe9bf07ee51f9 <
    2b3f79b90b231a682315fe2191bb71925650e183
  - >-
    Linux >= ddd89d0a059d8e9740c75a97e0efe9bf07ee51f9 <
    bbba4f92515238d76018e9b75e41b16d83df52c8
  - >-
    Linux >= ddd89d0a059d8e9740c75a97e0efe9bf07ee51f9 <
    1f5f94c6c6b2e4eaa5b45815509e21d0c6cfa81e
  - >-
    Linux >= ddd89d0a059d8e9740c75a97e0efe9bf07ee51f9 <
    32ac9097aa2463fcfc12f61cc4a9ebc3579cba7d
  - >-
    Linux >= ddd89d0a059d8e9740c75a97e0efe9bf07ee51f9 <
    929e4f044621c8cc30b612fb74e1410bef09e41b
  - Linux 5.8
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-16T18:53:00.610908Z'
published: '2026-08-15'
updated: '2026-10-16'
sourceUpdated: '2026-10-16T18:55:32.188Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-74312'
references:
  - url: 'https://git.kernel.org/stable/c/0f310bac6db9bd3bb1655707d692d9d2a86eeb17'
  - url: 'https://git.kernel.org/stable/c/4bf5a51963ff816f7443702dc536b9327cf5e550'
  - url: 'https://git.kernel.org/stable/c/55a644031e610ea93fbde2702c7b8f267476552f'
  - url: 'https://git.kernel.org/stable/c/2b3f79b90b231a682315fe2191bb71925650e183'
  - url: 'https://git.kernel.org/stable/c/bbba4f92515238d76018e9b75e41b16d83df52c8'
  - url: 'https://git.kernel.org/stable/c/1f5f94c6c6b2e4eaa5b45815509e21d0c6cfa81e'
  - url: 'https://git.kernel.org/stable/c/32ac9097aa2463fcfc12f61cc4a9ebc3579cba7d'
  - url: 'https://git.kernel.org/stable/c/929e4f044621c8cc30b612fb74e1410bef09e41b'
tags:
  - cve.org
epss: 0.00176
epssPercentile: 0.06639
ingestedAt: '2026-10-16T19:46:24.381Z'
---

## Overview

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

- `Linux >= ddd89d0a059d8e9740c75a97e0efe9bf07ee51f9 < 0f310bac6db9bd3bb1655707d692d9d2a86eeb17`
- `Linux >= ddd89d0a059d8e9740c75a97e0efe9bf07ee51f9 < 4bf5a51963ff816f7443702dc536b9327cf5e550`
- `Linux >= ddd89d0a059d8e9740c75a97e0efe9bf07ee51f9 < 55a644031e610ea93fbde2702c7b8f267476552f`
- `Linux >= ddd89d0a059d8e9740c75a97e0efe9bf07ee51f9 < 2b3f79b90b231a682315fe2191bb71925650e183`
- `Linux >= ddd89d0a059d8e9740c75a97e0efe9bf07ee51f9 < bbba4f92515238d76018e9b75e41b16d83df52c8`
- `Linux >= ddd89d0a059d8e9740c75a97e0efe9bf07ee51f9 < 1f5f94c6c6b2e4eaa5b45815509e21d0c6cfa81e`
- `Linux >= ddd89d0a059d8e9740c75a97e0efe9bf07ee51f9 < 32ac9097aa2463fcfc12f61cc4a9ebc3579cba7d`
- `Linux >= ddd89d0a059d8e9740c75a97e0efe9bf07ee51f9 < 929e4f044621c8cc30b612fb74e1410bef09e41b`
- `Linux 5.8`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.