{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\niommu/vt-d: Skip dev-iotlb flush for inaccessible PCIe device without scalable mode\n\nPCIe endpoints with ATS enabled and passed through to userspace\n(e.g., QEMU, DPDK) can hard-lock the host when their link drops,\neither by surprise removal or by a link fault.\n\nCommit 4fc82cd907ac (\"iommu/vt-d: Don\u0027t issue ATS Invalidation\nrequest when device is disconnected\") adds pci_dev_is_disconnected()\nto devtlb_invalidation_with_pasid() so ATS invalidation is skipped\nonly when the device is being safely removed, but it applies only\nwhen Intel IOMMU scalable mode is enabled.\n\nWith scalable mode disabled or unsupported, a system hard-lock\noccurs when a PCIe endpoint\u0027s link drops because the Intel IOMMU\nwaits indefinitely for an ATS invalidation that cannot complete.\n\nCall Trace:\n qi_submit_sync\n qi_flush_dev_iotlb\n __context_flush_dev_iotlb.part.0\n domain_context_clear_one_cb\n pci_for_each_dma_alias\n device_block_translation\n blocking_domain_attach_dev\n iommu_deinit_device\n __iommu_group_remove_device\n iommu_release_device\n iommu_bus_notifier\n blocking_notifier_call_chain\n bus_notify\n device_del\n pci_remove_bus_device\n pci_stop_and_remove_bus_device\n pciehp_unconfigure_device\n pciehp_disable_slot\n pciehp_handle_presence_or_link_change\n pciehp_ist\n\nCommit 81e921fd3216 (\"iommu/vt-d: Fix NULL domain on device release\")\nadds intel_pasid_teardown_sm_context() to intel_iommu_release_device(),\nwhich calls qi_flush_dev_iotlb() and can also hard-lock the system\nwhen a PCIe endpoint\u0027s link drops.\n\nCall Trace:\n qi_submit_sync\n qi_flush_dev_iotlb\n __context_flush_dev_iotlb.part.0\n intel_context_flush_no_pasid\n device_pasid_table_teardown\n pci_pasid_table_teardown\n pci_for_each_dma_alias\n intel_pasid_teardown_sm_context\n intel_iommu_release_device\n iommu_deinit_device\n __iommu_group_remove_device\n iommu_release_device\n iommu_bus_notifier\n blocking_notifier_call_chain\n bus_notify\n device_del\n pci_remove_bus_device\n pci_stop_and_remove_bus_device\n pciehp_unconfigure_device\n pciehp_disable_slot\n pciehp_handle_presence_or_link_change\n pciehp_ist\n\nSometimes the endpoint loses connection without a link-down event\n(e.g., due to a link fault); killing the process (virsh destroy)\nthen hard-locks the host.\n\nCall Trace:\n qi_submit_sync\n qi_flush_dev_iotlb\n __context_flush_dev_iotlb.part.0\n domain_context_clear_one_cb\n pci_for_each_dma_alias\n device_block_translation\n blocking_domain_attach_dev\n __iommu_attach_device\n __iommu_device_set_domain\n __iommu_group_set_domain_internal\n iommu_detach_group\n vfio_iommu_type1_detach_group\n vfio_group_detach_container\n vfio_group_fops_release\n __fput\n\npci_dev_is_disconnected() only covers safe-removal paths;\npci_device_is_present() tests accessibility by reading\nvendor/device IDs and internally calls pci_dev_is_disconnected().\nOn a ConnectX-5 (8 GT/s, x2) this costs ~70 \u00b5s.\n\nSince __context_flush_dev_iotlb() is only called on\n{attach,release}_dev paths (not hot), add pci_device_is_present()\nthere to skip inaccessible devices and avoid the hard-lock."
    }
  ],
  "id": "CVE-2026-43161",
  "lastModified": "2026-05-06T13:07:51.607",
  "metrics": {},
  "published": "2026-05-06T12:16:34.137",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/42662d19839f34735b718129ea200e3734b07e50"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/48b3f08e68b29a79527869cdde7298ca2a9b9646"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/bc0490ad9edf5c6f98e39fbbee2877b85261a5ae"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/e70d5feb10c5ba2bbf7ca400b8f39a2f82d653e8"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Awaiting Analysis"
}

{
  "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-2026-43161 iommu/vt-d: Skip dev-iotlb flush for inaccessible PCIe device without scalable mode - VEX",
        "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-43161.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": "iommu/vt-d: Skip dev-iotlb flush for inaccessible PCIe device without scalable mode",
    "tracking": {
      "current_release_date": "2026-05-08T01:43:14.000Z",
      "generator": {
        "date": "2026-05-08T07:05:39.070Z",
        "engine": {
          "name": "MSRC Generator",
          "version": "1.0"
        }
      },
      "id": "msrc_CVE-2026-43161",
      "initial_release_date": "2026-05-02T00:00:00.000Z",
      "revision_history": [
        {
          "date": "2026-05-07T01:05:01.000Z",
          "legacy_version": "1",
          "number": "1",
          "summary": "Information published."
        },
        {
          "date": "2026-05-07T14:39:26.000Z",
          "legacy_version": "1.1",
          "number": "2",
          "summary": "Information published."
        },
        {
          "date": "2026-05-08T01:43:14.000Z",
          "legacy_version": "2",
          "number": "3",
          "summary": "Information published."
        }
      ],
      "status": "final",
      "version": "3"
    }
  },
  "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 0:6.6.137.1-2.azl3",
                "product": {
                  "name": "azl3 kernel 0:6.6.137.1-2.azl3",
                  "product_id": "1"
                }
              }
            ],
            "category": "product_name",
            "name": "kernel"
          }
        ],
        "category": "vendor",
        "name": "Microsoft"
      }
    ],
    "relationships": [
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "azl3 kernel 0:6.6.137.1-2.azl3 as a component of Azure Linux 3.0",
          "product_id": "17084-1"
        },
        "product_reference": "1",
        "relates_to_product_reference": "17084"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2026-43161",
      "notes": [
        {
          "category": "general",
          "text": "Linux",
          "title": "Assigning CNA"
        }
      ],
      "product_status": {
        "known_affected": [
          "17084-1"
        ]
      },
      "references": [
        {
          "category": "self",
          "summary": "CVE-2026-43161 iommu/vt-d: Skip dev-iotlb flush for inaccessible PCIe device without scalable mode - VEX",
          "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-43161.json"
        }
      ],
      "remediations": [
        {
          "category": "none_available",
          "date": "2026-05-07T01:05:01.000Z",
          "details": "There is no fix available for this vulnerability as of now",
          "product_ids": [
            "17084-1"
          ]
        }
      ],
      "title": "iommu/vt-d: Skip dev-iotlb flush for inaccessible PCIe device without scalable mode"
    }
  ]
}

{
  "affected": [],
  "aliases": [
    "CVE-2026-43161"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-05-06T12:16:34Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\niommu/vt-d: Skip dev-iotlb flush for inaccessible PCIe device without scalable mode\n\nPCIe endpoints with ATS enabled and passed through to userspace\n(e.g., QEMU, DPDK) can hard-lock the host when their link drops,\neither by surprise removal or by a link fault.\n\nCommit 4fc82cd907ac (\"iommu/vt-d: Don\u0027t issue ATS Invalidation\nrequest when device is disconnected\") adds pci_dev_is_disconnected()\nto devtlb_invalidation_with_pasid() so ATS invalidation is skipped\nonly when the device is being safely removed, but it applies only\nwhen Intel IOMMU scalable mode is enabled.\n\nWith scalable mode disabled or unsupported, a system hard-lock\noccurs when a PCIe endpoint\u0027s link drops because the Intel IOMMU\nwaits indefinitely for an ATS invalidation that cannot complete.\n\nCall Trace:\n qi_submit_sync\n qi_flush_dev_iotlb\n __context_flush_dev_iotlb.part.0\n domain_context_clear_one_cb\n pci_for_each_dma_alias\n device_block_translation\n blocking_domain_attach_dev\n iommu_deinit_device\n __iommu_group_remove_device\n iommu_release_device\n iommu_bus_notifier\n blocking_notifier_call_chain\n bus_notify\n device_del\n pci_remove_bus_device\n pci_stop_and_remove_bus_device\n pciehp_unconfigure_device\n pciehp_disable_slot\n pciehp_handle_presence_or_link_change\n pciehp_ist\n\nCommit 81e921fd3216 (\"iommu/vt-d: Fix NULL domain on device release\")\nadds intel_pasid_teardown_sm_context() to intel_iommu_release_device(),\nwhich calls qi_flush_dev_iotlb() and can also hard-lock the system\nwhen a PCIe endpoint\u0027s link drops.\n\nCall Trace:\n qi_submit_sync\n qi_flush_dev_iotlb\n __context_flush_dev_iotlb.part.0\n intel_context_flush_no_pasid\n device_pasid_table_teardown\n pci_pasid_table_teardown\n pci_for_each_dma_alias\n intel_pasid_teardown_sm_context\n intel_iommu_release_device\n iommu_deinit_device\n __iommu_group_remove_device\n iommu_release_device\n iommu_bus_notifier\n blocking_notifier_call_chain\n bus_notify\n device_del\n pci_remove_bus_device\n pci_stop_and_remove_bus_device\n pciehp_unconfigure_device\n pciehp_disable_slot\n pciehp_handle_presence_or_link_change\n pciehp_ist\n\nSometimes the endpoint loses connection without a link-down event\n(e.g., due to a link fault); killing the process (virsh destroy)\nthen hard-locks the host.\n\nCall Trace:\n qi_submit_sync\n qi_flush_dev_iotlb\n __context_flush_dev_iotlb.part.0\n domain_context_clear_one_cb\n pci_for_each_dma_alias\n device_block_translation\n blocking_domain_attach_dev\n __iommu_attach_device\n __iommu_device_set_domain\n __iommu_group_set_domain_internal\n iommu_detach_group\n vfio_iommu_type1_detach_group\n vfio_group_detach_container\n vfio_group_fops_release\n __fput\n\npci_dev_is_disconnected() only covers safe-removal paths;\npci_device_is_present() tests accessibility by reading\nvendor/device IDs and internally calls pci_dev_is_disconnected().\nOn a ConnectX-5 (8 GT/s, x2) this costs ~70 \u00b5s.\n\nSince __context_flush_dev_iotlb() is only called on\n{attach,release}_dev paths (not hot), add pci_device_is_present()\nthere to skip inaccessible devices and avoid the hard-lock.",
  "id": "GHSA-jph2-qvw9-vvwq",
  "modified": "2026-05-06T12:30:31Z",
  "published": "2026-05-06T12:30:31Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-43161"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/42662d19839f34735b718129ea200e3734b07e50"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/48b3f08e68b29a79527869cdde7298ca2a9b9646"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/bc0490ad9edf5c6f98e39fbbee2877b85261a5ae"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e70d5feb10c5ba2bbf7ca400b8f39a2f82d653e8"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}