Vulnerability-Lookup

FKIE_CVE-2026-89445

Vulnerability from fkie_nvd - Published: 2026-09-11 20:19 - Updated: 2026-09-13 07:17

Severity

8.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Summary

In the Linux kernel, the following vulnerability has been resolved: iommufd: Fix UAF in selftest IOPF reporting IOMMUFD selftest TRIGGER_IOPF borrows an attach handle from group->pasid_array without synchronizing against PASID detach, then a concurrent iommu_report_device_fault() can dereference that borrowed handle's domain pointer after the detach erases the handle and frees the backing struct iommufd_attach_handle. TRIGGER_IOPF then dereferences the freed handle, causing a UAF. Fix by adding a iopf_rwsem in mock_dev to follow the expected design of a real driver. Hold its read side across the whole iommu_report_device_fault() call, and its write side around every path that attaches, detaches, or replaces a device domain. This can block new reports and drains in-flight reports before an old attach handle or the IOPF fault parameter can be removed. Also take the write side while registering a mock device, since it can invoke the mock driver's default-domain attach callback.

References

	URL	Tags
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/8c07df7cdfcf52f1ff276c588612aabc6c6b8399
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/cab2895729516799384d48560e6fca105fb3f927
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/e27e90bde68b2ab92e63ed19caad1ef57188bea0

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/iommu/iommufd/selftest.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "cab2895729516799384d48560e6fca105fb3f927",
              "status": "affected",
              "version": "ddee19971081b42615d62f4fdada21274708ed4d",
              "versionType": "git"
            },
            {
              "lessThan": "e27e90bde68b2ab92e63ed19caad1ef57188bea0",
              "status": "affected",
              "version": "ddee19971081b42615d62f4fdada21274708ed4d",
              "versionType": "git"
            },
            {
              "lessThan": "8c07df7cdfcf52f1ff276c588612aabc6c6b8399",
              "status": "affected",
              "version": "ddee19971081b42615d62f4fdada21274708ed4d",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/iommu/iommufd/selftest.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.11"
            },
            {
              "lessThan": "6.11",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.50",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc1",
              "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\niommufd: Fix UAF in selftest IOPF reporting\n\nIOMMUFD selftest TRIGGER_IOPF borrows an attach handle from\ngroup-\u003epasid_array without synchronizing against PASID detach,\nthen a concurrent iommu_report_device_fault() can dereference\nthat borrowed handle\u0027s domain pointer after the detach erases\nthe handle and frees the backing struct iommufd_attach_handle.\nTRIGGER_IOPF then dereferences the freed handle, causing a UAF.\n\nFix by adding a iopf_rwsem in mock_dev to follow the expected design\nof a real driver. Hold its read side across the whole\niommu_report_device_fault() call, and its write side around every\npath that attaches, detaches, or replaces a device domain.\nThis can block new reports and drains in-flight reports before an old\nattach handle or the IOPF fault parameter can be removed.\nAlso take the write side while registering a mock device, since\nit can invoke the mock driver\u0027s default-domain attach callback."
    }
  ],
  "id": "CVE-2026-89445",
  "lastModified": "2026-09-13T07:17:09.093",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 8.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "CHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 2.0,
        "impactScore": 6.0,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-09-11T20:19:24.990",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/8c07df7cdfcf52f1ff276c588612aabc6c6b8399"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/cab2895729516799384d48560e6fca105fb3f927"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/e27e90bde68b2ab92e63ed19caad1ef57188bea0"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}

CVE-2026-89445 (GCVE-0-2026-89445)

Vulnerability from cvelistv5 – Published: 2026-09-11 19:43 – Updated: 2026-09-13 06:29

Title

iommufd: Fix UAF in selftest IOPF reporting

Summary

Severity

8.8 (High)


                        
                          CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Assigner

Linux mitre root

References

3 references

URL	Tags
https://git.kernel.org/stable/c/cab28957295167993…
https://git.kernel.org/stable/c/e27e90bde68b2ab92…
https://git.kernel.org/stable/c/8c07df7cdfcf52f1f…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: ddee19971081b42615d62f4fdada21274708ed4d , < cab2895729516799384d48560e6fca105fb3f927 (git) Affected: ddee19971081b42615d62f4fdada21274708ed4d , < e27e90bde68b2ab92e63ed19caad1ef57188bea0 (git) Affected: ddee19971081b42615d62f4fdada21274708ed4d , < 8c07df7cdfcf52f1ff276c588612aabc6c6b8399 (git)
Linux	Linux	Affected: 6.11 Unaffected: 0 , < 6.11 (semver) Unaffected: 6.18.50 , ≤ 6.18.* (semver) Unaffected: 7.2.4 , ≤ 7.2.* (semver) Unaffected: 7.3-rc1 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/iommu/iommufd/selftest.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "cab2895729516799384d48560e6fca105fb3f927",
              "status": "affected",
              "version": "ddee19971081b42615d62f4fdada21274708ed4d",
              "versionType": "git"
            },
            {
              "lessThan": "e27e90bde68b2ab92e63ed19caad1ef57188bea0",
              "status": "affected",
              "version": "ddee19971081b42615d62f4fdada21274708ed4d",
              "versionType": "git"
            },
            {
              "lessThan": "8c07df7cdfcf52f1ff276c588612aabc6c6b8399",
              "status": "affected",
              "version": "ddee19971081b42615d62f4fdada21274708ed4d",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/iommu/iommufd/selftest.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.11"
            },
            {
              "lessThan": "6.11",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.50",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.50",
                  "versionStartIncluding": "6.11",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.4",
                  "versionStartIncluding": "6.11",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3-rc1",
                  "versionStartIncluding": "6.11",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\niommufd: Fix UAF in selftest IOPF reporting\n\nIOMMUFD selftest TRIGGER_IOPF borrows an attach handle from\ngroup-\u003epasid_array without synchronizing against PASID detach,\nthen a concurrent iommu_report_device_fault() can dereference\nthat borrowed handle\u0027s domain pointer after the detach erases\nthe handle and frees the backing struct iommufd_attach_handle.\nTRIGGER_IOPF then dereferences the freed handle, causing a UAF.\n\nFix by adding a iopf_rwsem in mock_dev to follow the expected design\nof a real driver. Hold its read side across the whole\niommu_report_device_fault() call, and its write side around every\npath that attaches, detaches, or replaces a device domain.\nThis can block new reports and drains in-flight reports before an old\nattach handle or the IOPF fault parameter can be removed.\nAlso take the write side while registering a mock device, since\nit can invoke the mock driver\u0027s default-domain attach callback."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 8.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - The UAF is reached only via local ioctls on /dev/iommu (or VFIO-compat /dev/vfio/vfio): IOMMU_TEST_CMD TRIGGER_IOPF calls iommu_report_device_fault() while a concurrent PASID/RID detach frees the attach handle. No network or packet-receive path exists.\nAC:L - The attacker controls both sides of the race by issuing concurrent IOMMU_TEST_OP_TRIGGER_IOPF and PASID_DETACH/REPLACE or mock-domain destroy on the same fd; iommu_attach_handle_get() does not keep the handle alive after lookup, so no victim timing or uncontrollable layout is required.\nPR:L - iommufd_fops_open() and IOMMU_TEST_CMD perform no capability checks; /dev/iommu is 0660 and MOCK_DOMAIN creates an IOPF-capable mock device without physical assignment, so an unprivileged local user with iommufd access (selftest/syzkaller kernels or VFIO/iommufd group membership) can trigger it without init-namespace root.\nUI:N - Exploitation requires no victim action; the attacker programmatically opens iommufd, creates a mock domain, attaches a PASID, and races TRIGGER_IOPF against detach through their own file descriptors and ioctls.\nS:C - The freed object is struct iommufd_attach_handle used by iommu_report_device_fault() to dispatch domain-\u003eiopf_handler and complete IOMMU page faults; pre-fix TRIGGER_IOPF also accepted any bound idev, so corrupting those handles can hijack IOMMU fault/DMA isolation across the device-assignment boundary.\nC:H - Use-after-free of iommufd_attach_handle lets an attacker reclaim the slab and control the domain pointer later read as attach_handle-\u003edomain-\u003eiopf_handler, enabling arbitrary kernel reads through the IOPF handler and fault-queue path.\nI:H - The UAF is a function-pointer dereference of domain-\u003eiopf_handler plus later handle use in iommufd_fault_iopf_handler; heap spraying yields an arbitrary write and control-flow hijack in the IOMMU fault-completion path.\nA:H - Dereferencing the freed attach handle in find_fault_handler()/iommu_report_device_fault() causes a kernel oops or panic; the UAF is reliably crashable even when not fully exploited for code execution."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-13T06:29:27.592Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/cab2895729516799384d48560e6fca105fb3f927"
        },
        {
          "url": "https://git.kernel.org/stable/c/e27e90bde68b2ab92e63ed19caad1ef57188bea0"
        },
        {
          "url": "https://git.kernel.org/stable/c/8c07df7cdfcf52f1ff276c588612aabc6c6b8399"
        }
      ],
      "title": "iommufd: Fix UAF in selftest IOPF reporting",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-89445",
    "datePublished": "2026-09-11T19:43:12.765Z",
    "dateReserved": "2026-09-11T19:38:34.704Z",
    "dateUpdated": "2026-09-13T06:29:27.592Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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