fkie_cve-2024-56619
Vulnerability from fkie_nvd
Published
2024-12-27 15:15
Modified
2025-02-11 16:15
Summary
In the Linux kernel, the following vulnerability has been resolved: nilfs2: fix potential out-of-bounds memory access in nilfs_find_entry() Syzbot reported that when searching for records in a directory where the inode's i_size is corrupted and has a large value, memory access outside the folio/page range may occur, or a use-after-free bug may be detected if KASAN is enabled. This is because nilfs_last_byte(), which is called by nilfs_find_entry() and others to calculate the number of valid bytes of directory data in a page from i_size and the page index, loses the upper 32 bits of the 64-bit size information due to an inappropriate type of local variable to which the i_size value is assigned. This caused a large byte offset value due to underflow in the end address calculation in the calling nilfs_find_entry(), resulting in memory access that exceeds the folio/page size. Fix this issue by changing the type of the local variable causing the bit loss from "unsigned int" to "u64". The return value of nilfs_last_byte() is also of type "unsigned int", but it is truncated so as not to exceed PAGE_SIZE and no bit loss occurs, so no change is required.
Impacted products
Vendor Product Version



{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnilfs2: fix potential out-of-bounds memory access in nilfs_find_entry()\n\nSyzbot reported that when searching for records in a directory where the\ninode\u0027s i_size is corrupted and has a large value, memory access outside\nthe folio/page range may occur, or a use-after-free bug may be detected if\nKASAN is enabled.\n\nThis is because nilfs_last_byte(), which is called by nilfs_find_entry()\nand others to calculate the number of valid bytes of directory data in a\npage from i_size and the page index, loses the upper 32 bits of the 64-bit\nsize information due to an inappropriate type of local variable to which\nthe i_size value is assigned.\n\nThis caused a large byte offset value due to underflow in the end address\ncalculation in the calling nilfs_find_entry(), resulting in memory access\nthat exceeds the folio/page size.\n\nFix this issue by changing the type of the local variable causing the bit\nloss from \"unsigned int\" to \"u64\".  The return value of nilfs_last_byte()\nis also of type \"unsigned int\", but it is truncated so as not to exceed\nPAGE_SIZE and no bit loss occurs, so no change is required."
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: nilfs2: se corrige un posible acceso a memoria fuera de los l\u00edmites en nilfs_find_entry() Syzbot inform\u00f3 que al buscar registros en un directorio donde el i_size del inodo est\u00e1 da\u00f1ado y tiene un valor grande, puede ocurrir un acceso a memoria fuera del rango de folio/p\u00e1gina, o puede detectarse un error de use-after-free si KASAN est\u00e1 habilitado. Esto se debe a que nilfs_last_byte(), que es llamado por nilfs_find_entry() y otros para calcular la cantidad de bytes v\u00e1lidos de datos de directorio en una p\u00e1gina a partir de i_size y el \u00edndice de p\u00e1gina, pierde los 32 bits superiores de la informaci\u00f3n de tama\u00f1o de 64 bits debido a un tipo inadecuado de variable local a la que se asigna el valor de i_size. Esto caus\u00f3 un valor de desplazamiento de bytes grande debido al desbordamiento en el c\u00e1lculo de la direcci\u00f3n final en la llamada nilfs_find_entry(), lo que result\u00f3 en un acceso a memoria que excede el tama\u00f1o de folio/p\u00e1gina. Solucione este problema cambiando el tipo de la variable local que causa la p\u00e9rdida de bits de \"unsigned int\" a \"u64\". El valor de retorno de nilfs_last_byte() tambi\u00e9n es del tipo \"unsigned int\", pero se trunca para no superar PAGE_SIZE y no se produce ninguna p\u00e9rdida de bits, por lo que no se requiere ning\u00fan cambio."
    }
  ],
  "id": "CVE-2024-56619",
  "lastModified": "2025-02-11T16:15:45.830",
  "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": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "type": "Secondary"
      }
    ]
  },
  "published": "2024-12-27T15:15:21.437",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/09d6d05579fd46e61abf6e457bb100ff11f3a9d3"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/31f7b57a77d4c82a34ddcb6ff35b5aa577ef153e"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/48eb6e7404948032bbe811c5affbe39f6b316951"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/5af8366625182f01f6d8465c9a3210574673af57"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/985ebec4ab0a28bb5910c3b1481a40fbf7f9e61d"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/c3afea07477baccdbdec4483f8d5e59d42a3f67f"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/e3732102a9d638d8627d14fdf7b208462f0520e0"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Awaiting Analysis",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-416"
        }
      ],
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "type": "Secondary"
    }
  ]
}


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