FKIE_CVE-2024-47660

Vulnerability from fkie_nvd - Published: 2024-10-09 14:15 - Updated: 2025-11-03 23:16
Severity ?
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: fsnotify: clear PARENT_WATCHED flags lazily In some setups directories can have many (usually negative) dentries. Hence __fsnotify_update_child_dentry_flags() function can take a significant amount of time. Since the bulk of this function happens under inode->i_lock this causes a significant contention on the lock when we remove the watch from the directory as the __fsnotify_update_child_dentry_flags() call from fsnotify_recalc_mask() races with __fsnotify_update_child_dentry_flags() calls from __fsnotify_parent() happening on children. This can lead upto softlockup reports reported by users. Fix the problem by calling fsnotify_update_children_dentry_flags() to set PARENT_WATCHED flags only when parent starts watching children. When parent stops watching children, clear false positive PARENT_WATCHED flags lazily in __fsnotify_parent() for each accessed child.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/172e422ffea20a89bfdc672741c1aad6fbb5044ePatch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/3f3ef1d9f66b93913ce2171120d9226b55acd41dPatch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/7ef1d2e240c32b1f337a37232d037b07e3919e1aPatch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/d8c42405fc3507cc43ba7e4986a773c3fc633f6ePatch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/f9a48bc3dd9099935751458a5bbbea4b7c28abc8Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/fc1b1e135c3f72382f792e6c319fc088d5523ad5Patch
af854a3a-2127-422b-91ae-364da2661108https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html
Impacted products
Vendor Product Version
linux linux_kernel *
linux linux_kernel *
linux linux_kernel *
linux linux_kernel *
linux linux_kernel *
To clipboard 

{
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "2C67534D-8BBC-4069-8DEA-62295B16358C",
              "versionEndExcluding": "5.10.226",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "043405A4-25FE-45D4-A7BB-2A0C3B7D17C1",
              "versionEndExcluding": "5.15.167",
              "versionStartIncluding": "5.11",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "790F505A-7933-48F1-B038-380A8BC5C153",
              "versionEndExcluding": "6.1.109",
              "versionStartIncluding": "5.16",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "A56A0460-B122-44D6-B0E6-26CE9C891536",
              "versionEndExcluding": "6.6.50",
              "versionStartIncluding": "6.2",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "F4469C96-A86B-4CC3-B2D5-C21B6B72641B",
              "versionEndExcluding": "6.10.9",
              "versionStartIncluding": "6.7",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfsnotify: clear PARENT_WATCHED flags lazily\n\nIn some setups directories can have many (usually negative) dentries.\nHence __fsnotify_update_child_dentry_flags() function can take a\nsignificant amount of time. Since the bulk of this function happens\nunder inode-\u003ei_lock this causes a significant contention on the lock\nwhen we remove the watch from the directory as the\n__fsnotify_update_child_dentry_flags() call from fsnotify_recalc_mask()\nraces with __fsnotify_update_child_dentry_flags() calls from\n__fsnotify_parent() happening on children. This can lead upto softlockup\nreports reported by users.\n\nFix the problem by calling fsnotify_update_children_dentry_flags() to\nset PARENT_WATCHED flags only when parent starts watching children.\n\nWhen parent stops watching children, clear false positive PARENT_WATCHED\nflags lazily in __fsnotify_parent() for each accessed child."
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: fsnotify: borrar indicadores PARENT_WATCHED de forma diferida En algunas configuraciones, los directorios pueden tener muchas entradas (normalmente negativas). Por lo tanto, la funci\u00f3n __fsnotify_update_child_dentry_flags() puede tardar una cantidad significativa de tiempo. Dado que la mayor parte de esta funci\u00f3n se realiza en inode-\u0026gt;i_lock, esto provoca una contenci\u00f3n significativa en el bloqueo cuando eliminamos la vigilancia del directorio, ya que la llamada __fsnotify_update_child_dentry_flags() desde fsnotify_recalc_mask() compite con las llamadas __fsnotify_update_child_dentry_flags() desde __fsnotify_parent() que ocurren en los hijos. Esto puede provocar informes de bloqueo suave informados por los usuarios. Solucione el problema llamando a fsnotify_update_children_dentry_flags() para establecer los indicadores PARENT_WATCHED solo cuando el padre comience a vigilar a los hijos. Cuando el padre deja de vigilar a los hijos, borra los indicadores de falsos positivos PARENT_WATCHED de forma diferida en __fsnotify_parent() para cada hijo al que acceda."
    }
  ],
  "id": "CVE-2024-47660",
  "lastModified": "2025-11-03T23:16:13.907",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "HIGH",
          "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"
      }
    ]
  },
  "published": "2024-10-09T14:15:07.730",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/172e422ffea20a89bfdc672741c1aad6fbb5044e"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/3f3ef1d9f66b93913ce2171120d9226b55acd41d"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/7ef1d2e240c32b1f337a37232d037b07e3919e1a"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/d8c42405fc3507cc43ba7e4986a773c3fc633f6e"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/f9a48bc3dd9099935751458a5bbbea4b7c28abc8"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/fc1b1e135c3f72382f792e6c319fc088d5523ad5"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "url": "https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-362"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



Detection rules are retrieved from Rulezet.