{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nibmasm: fix heap over-read in ibmasm_send_i2o_message()\n\nThe ibmasm_send_i2o_message() function uses get_dot_command_size() to\ncompute the byte count for memcpy_toio(), but this value is derived from\nuser-controlled fields in the dot_command_header (command_size: u8,\ndata_size: u16) and is never validated against the actual allocation size.\nA root user can write a small buffer with inflated header fields, causing\nmemcpy_toio() to read up to ~65 KB past the end of the allocation into\nadjacent kernel heap, which is then forwarded to the service processor\nover MMIO.\n\nSilently clamping the copy size is not sufficient: if the header fields\nclaim a larger size than the buffer, the SP receives a dot command whose\nown header is inconsistent with the I2O message length, which can cause\nthe SP to desynchronize. Reject such commands outright by returning\nfailure.\n\nValidate command_size before calling get_mfa_inbound() to avoid leaking\nan I2O message frame: reading INBOUND_QUEUE_PORT dequeues a hardware\nframe from the controller\u0027s free pool, and returning without a\ncorresponding set_mfa_inbound() call would permanently exhaust it.\n\nAdditionally, clamp command_size to I2O_COMMAND_SIZE before the\nmemcpy_toio() so the MMIO write stays within the I2O message frame,\nconsistent with the clamping already performed by outgoing_message_size()\nfor the header field."
    }
  ],
  "id": "CVE-2026-46064",
  "lastModified": "2026-05-27T14:48:03.013",
  "metrics": {},
  "published": "2026-05-27T14:17:26.867",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/9aad71144fa3682cca3837a06c8623016790e7ec"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/9e8f6c9d4ecddda2f28baa1678340286cff3969c"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/c1c2417c60dbdca5ebb00462f21ee71c2d7f7083"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/fd19eb1c75047a4ed4e855f56cafd704dc3914e0"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/fe31722b0194ff76bf8b461e8bf97a2081147787"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Awaiting Analysis"
}

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2026-46064"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-05-27T14:17:26Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nibmasm: fix heap over-read in ibmasm_send_i2o_message()\n\nThe ibmasm_send_i2o_message() function uses get_dot_command_size() to\ncompute the byte count for memcpy_toio(), but this value is derived from\nuser-controlled fields in the dot_command_header (command_size: u8,\ndata_size: u16) and is never validated against the actual allocation size.\nA root user can write a small buffer with inflated header fields, causing\nmemcpy_toio() to read up to ~65 KB past the end of the allocation into\nadjacent kernel heap, which is then forwarded to the service processor\nover MMIO.\n\nSilently clamping the copy size is not sufficient: if the header fields\nclaim a larger size than the buffer, the SP receives a dot command whose\nown header is inconsistent with the I2O message length, which can cause\nthe SP to desynchronize. Reject such commands outright by returning\nfailure.\n\nValidate command_size before calling get_mfa_inbound() to avoid leaking\nan I2O message frame: reading INBOUND_QUEUE_PORT dequeues a hardware\nframe from the controller\u0027s free pool, and returning without a\ncorresponding set_mfa_inbound() call would permanently exhaust it.\n\nAdditionally, clamp command_size to I2O_COMMAND_SIZE before the\nmemcpy_toio() so the MMIO write stays within the I2O message frame,\nconsistent with the clamping already performed by outgoing_message_size()\nfor the header field.",
  "id": "GHSA-4p2m-h7j8-hhxj",
  "modified": "2026-05-27T15:33:23Z",
  "published": "2026-05-27T15:33:22Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-46064"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/9aad71144fa3682cca3837a06c8623016790e7ec"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/9e8f6c9d4ecddda2f28baa1678340286cff3969c"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c1c2417c60dbdca5ebb00462f21ee71c2d7f7083"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/fd19eb1c75047a4ed4e855f56cafd704dc3914e0"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/fe31722b0194ff76bf8b461e8bf97a2081147787"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

{
  "document": {
    "category": "csaf_vex",
    "csaf_version": "2.0",
    "distribution": {
      "text": "Public",
      "tlp": {
        "label": "WHITE",
        "url": "https://www.first.org/tlp/"
      }
    },
    "lang": "en-US",
    "notes": [
      {
        "category": "general",
        "text": "To determine the support lifecycle for your software, see the Microsoft Support Lifecycle: https://support.microsoft.com/lifecycle",
        "title": "Additional Resources"
      },
      {
        "category": "legal_disclaimer",
        "text": "The information provided in the Microsoft Knowledge Base is provided \\\"as is\\\" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.",
        "title": "Disclaimer"
      }
    ],
    "publisher": {
      "category": "vendor",
      "contact_details": "secure@microsoft.com",
      "name": "Microsoft Security Response Center",
      "namespace": "https://msrc.microsoft.com"
    },
    "references": [
      {
        "category": "self",
        "summary": "CVE-2026-46064 ibmasm: fix heap over-read in ibmasm_send_i2o_message() - VEX",
        "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-46064.json"
      },
      {
        "category": "external",
        "summary": "Microsoft Support Lifecycle",
        "url": "https://support.microsoft.com/lifecycle"
      },
      {
        "category": "external",
        "summary": "Common Vulnerability Scoring System",
        "url": "https://www.first.org/cvss"
      }
    ],
    "title": "ibmasm: fix heap over-read in ibmasm_send_i2o_message()",
    "tracking": {
      "current_release_date": "2026-05-28T14:44:46.000Z",
      "generator": {
        "date": "2026-05-29T07:23:45.827Z",
        "engine": {
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        }
      },
      "id": "msrc_CVE-2026-46064",
      "initial_release_date": "2026-05-02T00:00:00.000Z",
      "revision_history": [
        {
          "date": "2026-05-28T01:01:51.000Z",
          "legacy_version": "1",
          "number": "1",
          "summary": "Information published."
        },
        {
          "date": "2026-05-28T14:44:46.000Z",
          "legacy_version": "2",
          "number": "2",
          "summary": "Information published."
        }
      ],
      "status": "final",
      "version": "2"
    }
  },
  "product_tree": {
    "branches": [
      {
        "branches": [
          {
            "branches": [
              {
                "category": "product_version",
                "name": "3.0",
                "product": {
                  "name": "Azure Linux 3.0",
                  "product_id": "17084"
                }
              }
            ],
            "category": "product_name",
            "name": "Azure Linux"
          },
          {
            "branches": [
              {
                "category": "product_version_range",
                "name": "azl3 kernel 0:6.6.139.1-1.azl3",
                "product": {
                  "name": "azl3 kernel 0:6.6.139.1-1.azl3",
                  "product_id": "1"
                }
              }
            ],
            "category": "product_name",
            "name": "kernel"
          }
        ],
        "category": "vendor",
        "name": "Microsoft"
      }
    ],
    "relationships": [
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "azl3 kernel 0:6.6.139.1-1.azl3 as a component of Azure Linux 3.0",
          "product_id": "17084-1"
        },
        "product_reference": "1",
        "relates_to_product_reference": "17084"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2026-46064",
      "notes": [
        {
          "category": "general",
          "text": "Linux",
          "title": "Assigning CNA"
        }
      ],
      "product_status": {
        "known_affected": [
          "17084-1"
        ]
      },
      "references": [
        {
          "category": "self",
          "summary": "CVE-2026-46064 ibmasm: fix heap over-read in ibmasm_send_i2o_message() - VEX",
          "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-46064.json"
        }
      ],
      "remediations": [
        {
          "category": "none_available",
          "date": "2026-05-28T01:01:51.000Z",
          "details": "There is no fix available for this vulnerability as of now",
          "product_ids": [
            "17084-1"
          ]
        }
      ],
      "title": "ibmasm: fix heap over-read in ibmasm_send_i2o_message()"
    }
  ]
}