CVE-2022-50630

Estado: AplazadaAlta (7.8)—

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,

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/

Detalles técnicos trazas, registros y código del informe original

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 */

CVSS

Versión: 3.1
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Puntuación base: 7.8

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 0.15%
Percentil entre todas las CVEs puntuadas: 4
Fecha de la puntuación: 6/10/2026

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

🎯 Técnicas ATT&CK

Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.

ExplotaciónT1068 Exploitation for Privilege Escalationprivilege escalation75 %
Impacto principalT1499.004 Application or System Exploitationimpact60 %
Impacto secundarioT1083 File and Directory Discoverydiscovery40 %

Vulnerabilidad local (AV:L/PR:L) que causa Use-After-Free en kernel Linux, permitiendo DoS o lectura de memoria del sistema; acceso local con privilegios de usuario.

Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.

🛡️ Mitigaciones ATT&CK que cubren estas técnicas

Threat Intelligence Program Filter Network Traffic Execution Prevention Application Isolation and Sandboxing Exploit Protection Update Software

Tecnologías afectadas (1)

⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.

Linux — Linux Kernel^AI

Referencias

JSON original (NVD)

Mostrar

{
  "id": "CVE-2022-50630",
  "cveTags": [],
  "metrics": {
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 7.8,
          "attackVector": "LOCAL",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 5.9,
        "exploitabilityScore": 1.8
      }
    ]
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  "affected": [
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      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
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          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
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          "versions": [
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          ],
          "programFiles": [
            "mm/hugetlb.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
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          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4.11"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "4.11",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "5.10.150",
              "versionType": "semver",
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            },
            {
              "status": "unaffected",
              "version": "5.15.75",
              "versionType": "semver",
              "lessThanOrEqual": "5.15.*"
            },
            {
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              "version": "5.19.17",
              "versionType": "semver",
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            },
            {
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              "version": "6.0.3",
              "versionType": "semver",
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            },
            {
              "status": "unaffected",
              "version": "6.1",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "mm/hugetlb.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2025-12-08T02:15:49.223",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/0db2efb3bff879566f05341d94c3de00ac95c4cc",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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    {
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      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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    {
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      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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    {
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      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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    {
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      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Deferred",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm: hugetlb: fix UAF in hugetlb_handle_userfault\n\nThe vma_lock and hugetlb_fault_mutex are dropped before handling userfault\nand reacquire them again after handle_userfault(), but reacquire the\nvma_lock could lead to UAF[1,2] due to the following race,\n\nhugetlb_fault\n  hugetlb_no_page\n    /*unlock vma_lock */\n    hugetlb_handle_userfault\n      handle_userfault\n        /* unlock mm->mmap_lock*/\n                                           vm_mmap_pgoff\n                                             do_mmap\n                                               mmap_region\n                                                 munmap_vma_range\n                                                   /* clean old vma */\n        /* lock vma_lock again  <--- UAF */\n    /* unlock vma_lock */\n\nSince the vma_lock will unlock immediately after\nhugetlb_handle_userfault(), let's drop the unneeded lock and unlock in\nhugetlb_handle_userfault() to fix the issue.\n\n[1] https://lore.kernel.org/linux-mm/000000000000d5e00a05e834962e@google.com/\n[2] https://lore.kernel.org/linux-mm/20220921014457.1668-1-liuzixian4@huawei.com/"
    }
  ],
  "lastModified": "2026-08-04T10:18:20.150",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}