{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-74312",
  "modified": "2026-10-09T11:39:44Z",
  "upstream": [
    "CVE-2026-74312"
  ],
  "published": "2026-08-15T06:04:33Z",
  "summary": "vhost/vdpa: validate virtqueue index in mmap and fault paths",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nvhost/vdpa: validate virtqueue index in mmap and fault paths\n\nvhost_vdpa_mmap() and vhost_vdpa_fault() use vma->vm_pgoff as a\nvirtqueue index for get_vq_notification(), but they do not validate\nthat the index is smaller than v->nvqs.\n\nThe ioctl path already performs both a bounds check and\narray_index_nospec(), but the mmap/fault path only checks that the\nindex fits in u16. This allows an out-of-range queue index to reach\ndriver-specific get_vq_notification() callbacks.\n\nFix this by extracting a unified vhost_vdpa_get_vq_notification()\nhelper that validates the queue index against v->nvqs and applies\narray_index_nospec() before calling the driver callback. Both the\nmmap and fault paths use this helper, and the bounds checking is\nconsolidated into a single location.\n\nFrom source inspection, the most defensible impact is out-of-bounds\naccess in the callback path, potentially leading to invalid PFN\nremaps and crash/DoS.",
  "severity": [
    {
      "type": "CVSS_V3",
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
    }
  ],
  "affected": [
    {
      "package": {
        "ecosystem": "Raspberry Pi OS:12",
        "name": "linux"
      },
      "versions": [
        "1:6.1.47-1+rpt4"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-2712",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v6",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7l",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v8",
            "binary_version": "1:6.1.47-1+rpt4"
          }
        ]
      },
      "database_specific": {
        "per_version": {
          "1:6.1.47-1+rpt4": {
            "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e",
            "upstream_version": "6.1.47",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.1.178",
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-74312"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/0f310bac6db9bd3bb1655707d692d9d2a86eeb17"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/4bf5a51963ff816f7443702dc536b9327cf5e550"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/55a644031e610ea93fbde2702c7b8f267476552f"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/2b3f79b90b231a682315fe2191bb71925650e183"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/bbba4f92515238d76018e9b75e41b16d83df52c8"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/1f5f94c6c6b2e4eaa5b45815509e21d0c6cfa81e"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/32ac9097aa2463fcfc12f61cc4a9ebc3579cba7d"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/929e4f044621c8cc30b612fb74e1410bef09e41b"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-08-17T05:50:24Z",
    "severity": {
      "source": "kernel CNA",
      "cvss_v3_score": 7.8,
      "cvss_v3_severity": "High",
      "scenario": "AV:L - The flaw is reached only via local mmap()/page-fault handling on /dev/vhost-vdpa-N (vma->vm_pgoff selects the virtqueue); there is no network, adjacent-radio, or physical-device path to this code.\nAC:L - Once the device node is open, the attacker fully controls vm_pgoff and can pick any index up to 65535; no race, rare config, or victim-dependent timing is required to hit the out-of-range callback.\nPR:L - vhost_vdpa_open()/mmap() perform no capable() checks; in typical cloud/hypervisor deployments the vhost-vdpa char device is held by an unprivileged VMM/QEMU account (or a compromised QEMU), not init-namespace root.\nUI:N - Exploitation requires only the attacker's own open/mmap of the vhost-vdpa device with a crafted pgoff; no separate victim mount, click, or administrative action is needed.\nS:U - Impact stays within the host kernel security domain reached through the vhost-vdpa interface; it is not a guest-to-host VM escape or IOMMU-boundary bypass by itself.\nC:H - An out-of-range index drives driver get_vq_notification() callbacks (e.g. vp_vdpa/ifcvf/pds/octeon) to read past vring metadata; the returned notify.addr is then used by vmf_insert_pfn(), enabling arbitrary physical-page mapping and kernel memory disclosure.\nI:H - The mmap mapping is write-only doorbell access; remapping an attacker-chosen physical page via the corrupted notify.addr grants a write primitive to arbitrary physical memory and device MMIO, supporting control-flow or privilege manipulation.\nA:H - Invalid or attacker-influenced PFN insertion during fault handling can BUG/oops the kernel immediately; even without full exploitation, the out-of-bounds callback access provides a reliable host crash/DoS vector."
    }
  }
}