CVE-2026-64291 (GCVE-0-2026-64291)
Vulnerability from cvelistv5
Published
2026-07-25 08:49
Modified
2026-08-17 04:52
Severity ?
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).
References
Impacted products
Vendor Product Version
Linux Linux Version: e36ba5ab808ef6237c3148d469c8238674230e2b
Version: e36ba5ab808ef6237c3148d469c8238674230e2b
Version: e36ba5ab808ef6237c3148d469c8238674230e2b
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/iommu/iommufd/eventq.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "f565297edf316016be4a1a9e2eb9f39359313f43",
              "status": "affected",
              "version": "e36ba5ab808ef6237c3148d469c8238674230e2b",
              "versionType": "git"
            },
            {
              "lessThan": "e7b5e55652746b1221b9c10ff80eae8a154101ba",
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              "versionType": "git"
            },
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              "status": "affected",
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              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/iommu/iommufd/eventq.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.15"
            },
            {
              "lessThan": "6.15",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.39",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.39",
                  "versionStartIncluding": "6.15",
                  "vulnerable": true
                },
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                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.4",
                  "versionStartIncluding": "6.15",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "6.15",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\niommufd: Set veventq_depth upper bound\n\niommufd_veventq_alloc() accepts any !0 veventq_depth from userspace, with\nan upper bound at U32_MAX.\n\nThis leaves a vulnerability where userspace can allocate excessively large\nqueues to exhaust kernel memory reserves.\n\nCap the veventq_depth (maximum number of entries) to 1 \u003c\u003c 19, matching the\nmaximum number of entries in the SMMUv3 EVTQ (the largest use case today)."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-17T04:52:48.275Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/f565297edf316016be4a1a9e2eb9f39359313f43"
        },
        {
          "url": "https://git.kernel.org/stable/c/e7b5e55652746b1221b9c10ff80eae8a154101ba"
        },
        {
          "url": "https://git.kernel.org/stable/c/6ebf2eb46fbd5b40393ff8fbb847ba96925beaff"
        }
      ],
      "title": "iommufd: Set veventq_depth upper bound",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-64291",
    "datePublished": "2026-07-25T08:49:30.686Z",
    "dateReserved": "2026-07-19T15:36:31.778Z",
    "dateUpdated": "2026-08-17T04:52:48.275Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


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