iommufd: Fix UAF in selftest IOPF reporting

{
  "id": "c5d1eb32b275cbd9fe96e8fbe3fab86791646d7d6f72b52d4c1f71b3af198aad",
  "url": "https://osv.dev/vulnerability/CVE-2026-89445",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "iommufd: Fix UAF in selftest IOPF reporting",
    "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.",
    "evidence": "osv:CVE-2026-89445",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.12.112",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.18.50",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "7.2.4",
            "evidence": "/affected/1/ranges"
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        "affected_versions": []
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    "severity": "high",
    "structured": {
      "id": "CVE-2026-89445",
      "aliases": [
        "CVE-2026-89445"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H"
        }
      ],
      "affected": [
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          "package": {
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            "ecosystem": "Linux"
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          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89445.json"
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      ],
      "modified": "2026-10-28T02:30:49.087201894Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/8c07df7cdfcf52f1ff276c588612aabc6c6b8399",
        "https://git.kernel.org/stable/c/cab2895729516799384d48560e6fca105fb3f927",
        "https://git.kernel.org/stable/c/e27e90bde68b2ab92e63ed19caad1ef57188bea0",
        "https://git.kernel.org/stable/c/fd2e7ac94d6d813548b021473c3dddc30c8c07d1",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89445.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-89445",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
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        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89445.json"
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    "related_cves": [
      {
        "value": "CVE-2026-89445",
        "evidence": "/id"
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    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
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  "source_id": "core-osv",
  "document_id": 517593,
  "published_at": "2026-09-11T19:43:12.765+00:00"
}