FKIE_CVE-2021-47342

Vulnerability from fkie_nvd - Published: 2024-05-21 15:15 - Updated: 2026-06-17 04:17
Severity
7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: ext4: fix possible UAF when remounting r/o a mmp-protected file system After commit 618f003199c6 ("ext4: fix memory leak in ext4_fill_super"), after the file system is remounted read-only, there is a race where the kmmpd thread can exit, causing sbi->s_mmp_tsk to point at freed memory, which the call to ext4_stop_mmpd() can trip over. Fix this by only allowing kmmpd() to exit when it is stopped via ext4_stop_mmpd(). Bug-Report-Link: <20210629143603.2166962-1-yebin10@huawei.com>
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/61bb4a1c417e5b95d9edb4f887f131de32e419cbPatch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/7ed572cdf11081f8f9e07abd4bea56a3f2c4edbdPatch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/b663890d854403e566169f7e90aed5cd6ff64f6bPatch
af854a3a-2127-422b-91ae-364da2661108https://git.kernel.org/stable/c/61bb4a1c417e5b95d9edb4f887f131de32e419cbPatch
af854a3a-2127-422b-91ae-364da2661108https://git.kernel.org/stable/c/7ed572cdf11081f8f9e07abd4bea56a3f2c4edbdPatch
af854a3a-2127-422b-91ae-364da2661108https://git.kernel.org/stable/c/b663890d854403e566169f7e90aed5cd6ff64f6bPatch
Impacted products
Vendor Product Version
linux linux_kernel *
linux linux_kernel *
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/ext4/mmp.c",
            "fs/ext4/super.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "b663890d854403e566169f7e90aed5cd6ff64f6b",
              "status": "affected",
              "version": "5e4f5138bd8522ebe231a137682d3857209a2c07",
              "versionType": "git"
            },
            {
              "lessThan": "7ed572cdf11081f8f9e07abd4bea56a3f2c4edbd",
              "status": "affected",
              "version": "eb7b40d9d3785f7a131fb0b1f89bb6efa46c1833",
              "versionType": "git"
            },
            {
              "lessThan": "61bb4a1c417e5b95d9edb4f887f131de32e419cb",
              "status": "affected",
              "version": "618f003199c6188e01472b03cdbba227f1dc5f24",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "cecfdb9cf9a700d1037066173abac0617f6788df",
              "versionType": "git"
            },
            {
              "lessThan": "5.13",
              "status": "affected",
              "version": "5.12.18",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/ext4/mmp.c",
            "fs/ext4/super.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "5.10.77",
              "status": "affected",
              "version": "5.10.51",
              "versionType": "semver"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "DF93F2A0-1BCC-4EC3-AF79-F186B97DF86D",
              "versionEndExcluding": "5.10.77",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "AEF57B20-E396-45AE-9BB3-AE6B11D9AC43",
              "versionEndExcluding": "5.13.3",
              "versionStartIncluding": "5.11",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\next4: fix possible UAF when remounting r/o a mmp-protected file system\n\nAfter commit 618f003199c6 (\"ext4: fix memory leak in\next4_fill_super\"), after the file system is remounted read-only, there\nis a race where the kmmpd thread can exit, causing sbi-\u003es_mmp_tsk to\npoint at freed memory, which the call to ext4_stop_mmpd() can trip\nover.\n\nFix this by only allowing kmmpd() to exit when it is stopped via\next4_stop_mmpd().\n\nBug-Report-Link: \u003c20210629143603.2166962-1-yebin10@huawei.com\u003e"
    },
    {
      "lang": "es",
      "value": " En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: ext4: corrige posible UAF al remontar el sistema de archivos protegido por r/oa mmp. Despu\u00e9s del commit 618f003199c6 (\"ext4: corrige la p\u00e9rdida de memoria en ext4_fill_super\"), despu\u00e9s de que se vuelve a montar el sistema de archivos solo que hay una ejecuci\u00f3n donde el hilo kmmpd puede salir, causando que sbi-\u0026gt;s_mmp_tsk apunte a la memoria liberada, con la que la llamada a ext4_stop_mmpd() puede tropezar. Solucione este problema permitiendo que kmmpd() salga solo cuando se detiene a trav\u00e9s de ext4_stop_mmpd(). Enlace de informe de error: \u0026lt;20210629143603.2166962-1-yebin10@huawei.com\u0026gt;"
    }
  ],
  "id": "CVE-2021-47342",
  "lastModified": "2026-06-17T04:17:14.620",
  "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": "nvd@nist.gov",
        "type": "Primary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2021-47342",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2024-05-28T18:31:24.504163Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2024-05-21T15:15:20.923",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/61bb4a1c417e5b95d9edb4f887f131de32e419cb"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/7ed572cdf11081f8f9e07abd4bea56a3f2c4edbd"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/b663890d854403e566169f7e90aed5cd6ff64f6b"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/61bb4a1c417e5b95d9edb4f887f131de32e419cb"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/7ed572cdf11081f8f9e07abd4bea56a3f2c4edbd"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/b663890d854403e566169f7e90aed5cd6ff64f6b"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-416"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}


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