mm: hugetlb: fix UAF in hugetlb_handle_userfault

{
  "id": "b610d972f4bf03ea0f95430e1d04366095a7e651699264db796d806bf0b9e685",
  "url": "https://osv.dev/vulnerability/CVE-2022-50630",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "mm: hugetlb: fix UAF in hugetlb_handle_userfault",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: mm: hugetlb: fix UAF in hugetlb_handle_userfault The vma_lock and hugetlb_fault_mutex are dropped before handling userfault and reacquire them again after handle_userfault(), but reacquire the vma_lock could lead to UAF[1,2] due to the following race, hugetlb_fault hugetlb_no_page /*unlock vma_lock */ hugetlb_handle_userfault handle_userfault /* unlock mm->mmap_lock*/ vm_mmap_pgoff do_mmap mmap_region munmap_vma_range /* clean old vma */ /* lock vma_lock again <--- UAF */ /* unlock vma_lock */ Since the vma_lock will unlock immediately after hugetlb_handle_userfault(), let's drop the unneeded lock and unlock in hugetlb_handle_userfault() to fix the issue. [1] https://lore.kernel.org/linux-mm/000000000000d5e00a05e834962e@google.com/ [2] https://lore.kernel.org/linux-mm/20220921014457.1668-1-liuzixian4@huawei.com/",
    "evidence": "osv:CVE-2022-50630",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
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        "prerequisites": [],
        "fixed_versions": [
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            "evidence": "/affected/1/ranges"
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    "severity": "high",
    "structured": {
      "id": "CVE-2022-50630",
      "aliases": [
        "CVE-2022-50630"
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      "metrics": [
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          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
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            "ecosystem": "Linux"
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      "modified": "2026-10-28T02:30:41.884859135Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/0db2efb3bff879566f05341d94c3de00ac95c4cc",
        "https://git.kernel.org/stable/c/45c33966759ea1b4040c08dacda99ef623c0ca29",
        "https://git.kernel.org/stable/c/78504bcedb2f1bbfb353b4d233c24d641c4dda33",
        "https://git.kernel.org/stable/c/958f32ce832ba781ac20e11bb2d12a9352ea28fc",
        "https://git.kernel.org/stable/c/dd691973f67b2800a97db723b1ff6f07fdcf7f5a",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/50xxx/CVE-2022-50630.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2022-50630",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
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    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
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  "source_id": "core-osv",
  "document_id": 509264,
  "published_at": "2025-12-08T01:16:45.555+00:00"
}