FKIE_CVE-2026-97994

Vulnerability from fkie_nvd - Published: 2026-09-25 11:17 - Updated: 2026-10-19 10:17
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: vhost/vdpa: reject VRING_NUM larger than device max vhost_vring_set_num() accepts any non-zero power-of-two queue size that fits in 16 bits. vhost-vdpa then passes that value to set_vq_num() without comparing it with get_vq_num_max(). A process with access to /dev/vhost-vdpa-* can therefore configure a queue larger than the device advertises. With vdpa_sim, the worker can walk descriptors beyond the mapped descriptor ring. KASAN reports a 16-byte out-of-bounds read, corresponding to one vring_desc, in the vringh IOTLB path: BUG: KASAN: out-of-bounds in _copy_from_iter Read of size 16 copy_from_iotlb copydesc_iotlb vringh_getdesc_iotlb vdpasim_net_work Cache get_vq_num_max() immediately after reset. Some backends derive it from writable queue-size state, so querying it after SET_NUM may return the current size instead of the device capability. Invalidate the cached value before reset so a failed reset leaves SET_NUM disabled. For VHOST_SET_VRING_NUM, copy the complete vring state once and use the same index and size for validation, vq->num, and set_vq_num(). This ensures that validation and use operate on the same copied values.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/1d09201d81b7d3e276860cc7b7dbf6c6cbe8e9b4
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/4875c65ca53797a0a402fe2bb54d1b12f28b3cda
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/59522639a7d71cff4e20d594d0b9ea30dd0c77e0
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/68232102f20fc961327fb9e0f605a7eaadf030a9
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/ccb1dc7c527f8c925925cf92afc76ae590dac311
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/vhost/vdpa.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "4875c65ca53797a0a402fe2bb54d1b12f28b3cda",
              "status": "affected",
              "version": "4c8cf31885f69e86be0b5b9e6677a26797365e1d",
              "versionType": "git"
            },
            {
              "lessThan": "1d09201d81b7d3e276860cc7b7dbf6c6cbe8e9b4",
              "status": "affected",
              "version": "4c8cf31885f69e86be0b5b9e6677a26797365e1d",
              "versionType": "git"
            },
            {
              "lessThan": "68232102f20fc961327fb9e0f605a7eaadf030a9",
              "status": "affected",
              "version": "4c8cf31885f69e86be0b5b9e6677a26797365e1d",
              "versionType": "git"
            },
            {
              "lessThan": "59522639a7d71cff4e20d594d0b9ea30dd0c77e0",
              "status": "affected",
              "version": "4c8cf31885f69e86be0b5b9e6677a26797365e1d",
              "versionType": "git"
            },
            {
              "lessThan": "ccb1dc7c527f8c925925cf92afc76ae590dac311",
              "status": "affected",
              "version": "4c8cf31885f69e86be0b5b9e6677a26797365e1d",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/vhost/vdpa.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.7"
            },
            {
              "lessThan": "5.7",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.158",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.111",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.53",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.7",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvhost/vdpa: reject VRING_NUM larger than device max\n\nvhost_vring_set_num() accepts any non-zero power-of-two queue size that\nfits in 16 bits. vhost-vdpa then passes that value to set_vq_num()\nwithout comparing it with get_vq_num_max().\n\nA process with access to /dev/vhost-vdpa-* can therefore configure a\nqueue larger than the device advertises. With vdpa_sim, the worker can\nwalk descriptors beyond the mapped descriptor ring. KASAN reports a\n16-byte out-of-bounds read, corresponding to one vring_desc, in the\nvringh IOTLB path:\n\n  BUG: KASAN: out-of-bounds in _copy_from_iter\n  Read of size 16\n  copy_from_iotlb\n  copydesc_iotlb\n  vringh_getdesc_iotlb\n  vdpasim_net_work\n\nCache get_vq_num_max() immediately after reset. Some backends derive\nit from writable queue-size state, so querying it after SET_NUM may\nreturn the current size instead of the device capability. Invalidate\nthe cached value before reset so a failed reset leaves SET_NUM\ndisabled.\n\nFor VHOST_SET_VRING_NUM, copy the complete vring state once and use\nthe same index and size for validation, vq-\u003enum, and set_vq_num().\nThis ensures that validation and use operate on the same copied values."
    }
  ],
  "id": "CVE-2026-97994",
  "lastModified": "2026-10-19T10:17:50.850",
  "metrics": {},
  "published": "2026-09-25T11:17:27.637",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/1d09201d81b7d3e276860cc7b7dbf6c6cbe8e9b4"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/4875c65ca53797a0a402fe2bb54d1b12f28b3cda"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/59522639a7d71cff4e20d594d0b9ea30dd0c77e0"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/68232102f20fc961327fb9e0f605a7eaadf030a9"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/ccb1dc7c527f8c925925cf92afc76ae590dac311"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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