FKIE_CVE-2021-47461

Vulnerability from fkie_nvd - Published: 2024-05-22 07:15 - Updated: 2026-08-04 10:17
Severity
7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
4.7 (Medium) - CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: userfaultfd: fix a race between writeprotect and exit_mmap() A race is possible when a process exits, its VMAs are removed by exit_mmap() and at the same time userfaultfd_writeprotect() is called. The race was detected by KASAN on a development kernel, but it appears to be possible on vanilla kernels as well. Use mmget_not_zero() to prevent the race as done in other userfaultfd operations.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/149958ecd0627a9f1e9c678c25c665400054cd6aPatch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/3cda4bfffd4f755645577aaa9e96a606657b4525Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/cb185d5f1ebf900f4ae3bf84cee212e6dd035acaPatch
af854a3a-2127-422b-91ae-364da2661108https://git.kernel.org/stable/c/149958ecd0627a9f1e9c678c25c665400054cd6aPatch
af854a3a-2127-422b-91ae-364da2661108https://git.kernel.org/stable/c/3cda4bfffd4f755645577aaa9e96a606657b4525Patch
af854a3a-2127-422b-91ae-364da2661108https://git.kernel.org/stable/c/cb185d5f1ebf900f4ae3bf84cee212e6dd035acaPatch
Impacted products
Vendor Product Version
linux linux_kernel *
linux linux_kernel *
linux linux_kernel 5.15
linux linux_kernel 5.15
linux linux_kernel 5.15
linux linux_kernel 5.15
linux linux_kernel 5.15
linux linux_kernel 5.15
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/userfaultfd.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "3cda4bfffd4f755645577aaa9e96a606657b4525",
              "status": "affected",
              "version": "63b2d4174c4ad1f40b48d7138e71bcb564c1fe03",
              "versionType": "git"
            },
            {
              "lessThan": "149958ecd0627a9f1e9c678c25c665400054cd6a",
              "status": "affected",
              "version": "63b2d4174c4ad1f40b48d7138e71bcb564c1fe03",
              "versionType": "git"
            },
            {
              "lessThan": "cb185d5f1ebf900f4ae3bf84cee212e6dd035aca",
              "status": "affected",
              "version": "63b2d4174c4ad1f40b48d7138e71bcb564c1fe03",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/userfaultfd.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.7"
            },
            {
              "lessThan": "5.7",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.76",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.14.*",
              "status": "unaffected",
              "version": "5.14.15",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "5.15",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "337EB464-BC23-4BF5-B901-A933B3ABA6A7",
              "versionEndExcluding": "5.10.76",
              "versionStartIncluding": "5.7",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "63BD46C4-473F-45F9-93E9-F67D955321D8",
              "versionEndExcluding": "5.14.15",
              "versionStartIncluding": "5.11",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:5.15:rc1:*:*:*:*:*:*",
              "matchCriteriaId": "E46C74C6-B76B-4C94-A6A4-FD2FFF62D644",
              "vulnerable": true
            },
            {
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              "matchCriteriaId": "60134C3A-06E4-48C1-B04F-2903732A4E56",
              "vulnerable": true
            },
            {
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              "matchCriteriaId": "0460DA88-8FE1-46A2-9DDA-1F1ABA552E71",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:5.15:rc4:*:*:*:*:*:*",
              "matchCriteriaId": "AF55383D-4DF2-45DC-93F7-571F4F978EAB",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:5.15:rc5:*:*:*:*:*:*",
              "matchCriteriaId": "9E9481B2-8AA6-4CBD-B5D3-C10F51FF6D01",
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          "negate": false,
          "operator": "OR"
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      ]
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  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nuserfaultfd: fix a race between writeprotect and exit_mmap()\n\nA race is possible when a process exits, its VMAs are removed by\nexit_mmap() and at the same time userfaultfd_writeprotect() is called.\n\nThe race was detected by KASAN on a development kernel, but it appears\nto be possible on vanilla kernels as well.\n\nUse mmget_not_zero() to prevent the race as done in other userfaultfd\noperations."
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: userfaultfd: corrige una ejecuci\u00f3n entre writeprotect y exit_mmap() Una ejecuci\u00f3n es posible cuando un proceso sale, sus VMA son eliminados por exit_mmap() y al mismo tiempo se llama a userfaultfd_writeprotect() . KASAN detect\u00f3 la ejecuci\u00f3n en un n\u00facleo de desarrollo, pero parece ser posible tambi\u00e9n en n\u00facleos de vainilla. Utilice mmget_not_zero() para evitar la ejecuci\u00f3n como se hace en otras operaciones de userfaultfd."
    }
  ],
  "id": "CVE-2021-47461",
  "lastModified": "2026-08-04T10:17:04.587",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      },
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        "cvssData": {
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          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 4.7,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.0,
        "impactScore": 3.6,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2021-47461",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2024-05-22T18:15:05.306200Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2024-05-22T07:15:11.040",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
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      "url": "https://git.kernel.org/stable/c/149958ecd0627a9f1e9c678c25c665400054cd6a"
    },
    {
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      "tags": [
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      "url": "https://git.kernel.org/stable/c/3cda4bfffd4f755645577aaa9e96a606657b4525"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
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      "url": "https://git.kernel.org/stable/c/cb185d5f1ebf900f4ae3bf84cee212e6dd035aca"
    },
    {
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      "url": "https://git.kernel.org/stable/c/149958ecd0627a9f1e9c678c25c665400054cd6a"
    },
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      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
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  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-362"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}



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