fkie_cve-2024-49964
Vulnerability from fkie_nvd
Published
2024-10-21 18:15
Modified
2024-11-07 19:20
Severity ?
5.5 (Medium) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: mm/hugetlb: fix memfd_pin_folios free_huge_pages leak memfd_pin_folios followed by unpin_folios fails to restore free_huge_pages if the pages were not already faulted in, because the folio refcount for pages created by memfd_alloc_folio never goes to 0. memfd_pin_folios needs another folio_put to undo the folio_try_get below: memfd_alloc_folio() alloc_hugetlb_folio_nodemask() dequeue_hugetlb_folio_nodemask() dequeue_hugetlb_folio_node_exact() folio_ref_unfreeze(folio, 1); ; adds 1 refcount folio_try_get() ; adds 1 refcount hugetlb_add_to_page_cache() ; adds 512 refcount (on x86) With the fix, after memfd_pin_folios + unpin_folios, the refcount for the (unfaulted) page is 512, which is correct, as the refcount for a faulted unpinned page is 513.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/59e081ff2e91bbf19b8c1ecb75b031f778858383Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/c56b6f3d801d7ec8965993342bdd9e2972b6cb8ePatch
Impacted products
Vendor Product Version
linux linux_kernel *


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{
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "54D9C704-D679-41A7-9C40-10A6B1E7FFE9",
              "versionEndExcluding": "6.11.3",
              "versionStartIncluding": "6.11",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/hugetlb: fix memfd_pin_folios free_huge_pages leak\n\nmemfd_pin_folios followed by unpin_folios fails to restore free_huge_pages\nif the pages were not already faulted in, because the folio refcount for\npages created by memfd_alloc_folio never goes to 0.  memfd_pin_folios\nneeds another folio_put to undo the folio_try_get below:\n\nmemfd_alloc_folio()\n  alloc_hugetlb_folio_nodemask()\n    dequeue_hugetlb_folio_nodemask()\n      dequeue_hugetlb_folio_node_exact()\n        folio_ref_unfreeze(folio, 1);    ; adds 1 refcount\n  folio_try_get()                        ; adds 1 refcount\n  hugetlb_add_to_page_cache()            ; adds 512 refcount (on x86)\n\nWith the fix, after memfd_pin_folios + unpin_folios, the refcount for the\n(unfaulted) page is 512, which is correct, as the refcount for a faulted\nunpinned page is 513."
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: mm/hugetlb: se corrige la fuga de free_huge_pages de memfd_pin_folios memfd_pin_folios seguido de unpin_folios no puede restaurar free_huge_pages si las p\u00e1ginas no ten\u00edan ya un error, porque el recuento de referencias de folio para las p\u00e1ginas creadas por memfd_alloc_folio nunca llega a 0. memfd_pin_folios necesita otro folio_put para deshacer el folio_try_get a continuaci\u00f3n: memfd_alloc_folio() alloc_hugetlb_folio_nodemask() dequeue_hugetlb_folio_nodemask() dequeue_hugetlb_folio_node_exact() folio_ref_unfreeze(folio, 1); ; agrega 1 recuento de referencias folio_try_get() ; agrega 1 recuento de referencias hugetlb_add_to_page_cache() ; agrega 512 refcount (en x86) Con la soluci\u00f3n, despu\u00e9s de memfd_pin_folios + unpin_folios, el refcount para la p\u00e1gina (sin fallos) es 512, lo cual es correcto, ya que el refcount para una p\u00e1gina sin fijar con fallos es 513."
    }
  ],
  "id": "CVE-2024-49964",
  "lastModified": "2024-11-07T19:20:04.357",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 5.5,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 3.6,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ]
  },
  "published": "2024-10-21T18:15:17.510",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/59e081ff2e91bbf19b8c1ecb75b031f778858383"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/c56b6f3d801d7ec8965993342bdd9e2972b6cb8e"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "NVD-CWE-Other"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}


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