iommufd: Set veventq_depth upper bound

{
  "id": "37222bd3d8a784794a037c319cf1ae092bffd1a585e1906554e83e6468a3dd7a",
  "url": "https://osv.dev/vulnerability/CVE-2026-64291",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "iommufd: Set veventq_depth upper bound",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: iommufd: Set veventq_depth upper bound iommufd_veventq_alloc() accepts any !0 veventq_depth from userspace, with an upper bound at U32_MAX. This leaves a vulnerability where userspace can allocate excessively large queues to exhaust kernel memory reserves. Cap the veventq_depth (maximum number of entries) to 1 << 19, matching the maximum number of entries in the SMMUv3 EVTQ (the largest use case today).",
    "evidence": "osv:CVE-2026-64291",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.18.39",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "7.1.4",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-64291",
      "aliases": [
        "CVE-2026-64291"
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "e36ba5ab808ef6237c3148d469c8238674230e2b"
                },
                {
                  "fixed": "f565297edf316016be4a1a9e2eb9f39359313f43"
                },
                {
                  "fixed": "e7b5e55652746b1221b9c10ff80eae8a154101ba"
                },
                {
                  "fixed": "6ebf2eb46fbd5b40393ff8fbb847ba96925beaff"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64291.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.15.0"
                },
                {
                  "fixed": "6.18.39"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.19.0"
                },
                {
                  "fixed": "7.1.4"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64291.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:37.017104071Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/6ebf2eb46fbd5b40393ff8fbb847ba96925beaff",
        "https://git.kernel.org/stable/c/e7b5e55652746b1221b9c10ff80eae8a154101ba",
        "https://git.kernel.org/stable/c/f565297edf316016be4a1a9e2eb9f39359313f43",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64291.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-64291",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64291.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-64291",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 504118,
  "published_at": "2026-07-25T08:49:30.686+00:00"
}