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CVE-2026-74312 (GCVE-0-2026-74312)

Vulnerability from cvelistv5 – Published: 2026-08-15 05:58 – Updated: 2026-08-17 05:45
VLAI
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(), 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.
Severity
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: ddd89d0a059d8e9740c75a97e0efe9bf07ee51f9 , < 0f310bac6db9bd3bb1655707d692d9d2a86eeb17 (git)
Affected: ddd89d0a059d8e9740c75a97e0efe9bf07ee51f9 , < 4bf5a51963ff816f7443702dc536b9327cf5e550 (git)
Affected: ddd89d0a059d8e9740c75a97e0efe9bf07ee51f9 , < 55a644031e610ea93fbde2702c7b8f267476552f (git)
Affected: ddd89d0a059d8e9740c75a97e0efe9bf07ee51f9 , < 2b3f79b90b231a682315fe2191bb71925650e183 (git)
Affected: ddd89d0a059d8e9740c75a97e0efe9bf07ee51f9 , < bbba4f92515238d76018e9b75e41b16d83df52c8 (git)
Affected: ddd89d0a059d8e9740c75a97e0efe9bf07ee51f9 , < 1f5f94c6c6b2e4eaa5b45815509e21d0c6cfa81e (git)
Affected: ddd89d0a059d8e9740c75a97e0efe9bf07ee51f9 , < 32ac9097aa2463fcfc12f61cc4a9ebc3579cba7d (git)
Affected: ddd89d0a059d8e9740c75a97e0efe9bf07ee51f9 , < 929e4f044621c8cc30b612fb74e1410bef09e41b (git)
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Linux Linux Affected: 5.8
Unaffected: 0 , < 5.8 (semver)
Unaffected: 5.10.261 , ≤ 5.10.* (semver)
Unaffected: 5.15.212 , ≤ 5.15.* (semver)
Unaffected: 6.1.178 , ≤ 6.1.* (semver)
Unaffected: 6.6.145 , ≤ 6.6.* (semver)
Unaffected: 6.12.97 , ≤ 6.12.* (semver)
Unaffected: 6.18.40 , ≤ 6.18.* (semver)
Unaffected: 7.1.5 , ≤ 7.1.* (semver)
Unaffected: 7.2 , ≤ * (original_commit_for_fix)
guessed Create a notification for this product.
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          "lang": "en",
          "value": "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-\u003evm_pgoff as a\nvirtqueue index for get_vq_notification(), but they do not validate\nthat the index is smaller than v-\u003envqs.\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-\u003envqs 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."
        }
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            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
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              "value": "AV:L - The flaw is reached only via local mmap()/page-fault handling on /dev/vhost-vdpa-N (vma-\u003evm_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\u0027s 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."
            }
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        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
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          "url": "https://git.kernel.org/stable/c/4bf5a51963ff816f7443702dc536b9327cf5e550"
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    "datePublished": "2026-08-15T05:58:11.395Z",
    "dateReserved": "2026-08-15T05:44:03.883Z",
    "dateUpdated": "2026-08-17T05:45:44.929Z",
    "state": "PUBLISHED"
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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-\u003envqs 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.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"drivers/vhost/vdpa.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"ddd89d0a059d8e9740c75a97e0efe9bf07ee51f9\",\"lessThan\":\"0f310bac6db9bd3bb1655707d692d9d2a86eeb17\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"ddd89d0a059d8e9740c75a97e0efe9bf07ee51f9\",\"lessThan\":\"4bf5a51963ff816f7443702dc536b9327cf5e550\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"ddd89d0a059d8e9740c75a97e0efe9bf07ee51f9\",\"lessThan\":\"55a644031e610ea93fbde2702c7b8f267476552f\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"ddd89d0a059d8e9740c75a97e0efe9bf07ee51f9\",\"lessThan\":\"2b3f79b90b231a682315fe2191bb71925650e183\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"ddd89d0a059d8e9740c75a97e0efe9bf07ee51f9\",\"lessThan\":\"bbba4f92515238d76018e9b75e41b16d83df52c8\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"ddd89d0a059d8e9740c75a97e0efe9bf07ee51f9\",\"lessThan\":\"1f5f94c6c6b2e4eaa5b45815509e21d0c6cfa81e\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"ddd89d0a059d8e9740c75a97e0efe9bf07ee51f9\",\"lessThan\":\"32ac9097aa2463fcfc12f61cc4a9ebc3579cba7d\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"ddd89d0a059d8e9740c75a97e0efe9bf07ee51f9\",\"lessThan\":\"929e4f044621c8cc30b612fb74e1410bef09e41b\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"drivers/vhost/vdpa.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"5.8\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"5.8\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.10.261\",\"lessThanOrEqual\":\"5.10.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.15.212\",\"lessThanOrEqual\":\"5.15.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.1.178\",\"lessThanOrEqual\":\"6.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.6.145\",\"lessThanOrEqual\":\"6.6.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.12.97\",\"lessThanOrEqual\":\"6.12.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.18.40\",\"lessThanOrEqual\":\"6.18.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.1.5\",\"lessThanOrEqual\":\"7.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.2\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H\",\"baseScore\":7.8,\"baseSeverity\":\"HIGH\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":1.8,\"impactScore\":5.9}]},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/0f310bac6db9bd3bb1655707d692d9d2a86eeb17\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/1f5f94c6c6b2e4eaa5b45815509e21d0c6cfa81e\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/2b3f79b90b231a682315fe2191bb71925650e183\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/32ac9097aa2463fcfc12f61cc4a9ebc3579cba7d\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/4bf5a51963ff816f7443702dc536b9327cf5e550\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/55a644031e610ea93fbde2702c7b8f267476552f\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/929e4f044621c8cc30b612fb74e1410bef09e41b\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/bbba4f92515238d76018e9b75e41b16d83df52c8\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}",
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-08-20T16:57:49+00:00",
      "cve": "CVE-2026-74312",
      "id": "CVE-2026-74312",
      "initial_release_date": "2026-08-15T00:00:00+00:00",
      "product_status:known_affected": "232",
      "product_status:known_not_affected": "42",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: vhost/vdpa: validate virtqueue index in mmap and fault paths",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-74312.json",
      "version": "3"
    }
  }
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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