fkie_cve-2021-47649
Vulnerability from fkie_nvd
Published
2025-02-26 06:37
Modified
2025-10-14 19:08
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: udmabuf: validate ubuf->pagecount Syzbot has reported GPF in sg_alloc_append_table_from_pages(). The problem was in ubuf->pages == ZERO_PTR. ubuf->pagecount is calculated from arguments passed from user-space. If user creates udmabuf with list.size == 0 then ubuf->pagecount will be also equal to zero; it causes kmalloc_array() to return ZERO_PTR. Fix it by validating ubuf->pagecount before passing it to kmalloc_array().
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/2b6dd600dd72573c23ea180b5b0b2f1813405882Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/5d50f851dd307c07ca5591297093f19967c834a9Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/811b667cefbea9cb7511a874b169d6a92907137ePatch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/9e9b4a269f84d3230f2af84ff42322db676440d9Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/a3728d32fc61eb0fe283cb8ff60b2c8f751e2202Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/b267a8118c2b171bf7d67b90ed64154eeab9fae0Patch
Impacted products
Vendor Product Version
linux linux_kernel *
linux linux_kernel *
linux linux_kernel *
linux linux_kernel *
linux linux_kernel *


To clipboard 

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  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nudmabuf: validate ubuf-\u003epagecount\n\nSyzbot has reported GPF in sg_alloc_append_table_from_pages(). The\nproblem was in ubuf-\u003epages == ZERO_PTR.\n\nubuf-\u003epagecount is calculated from arguments passed from user-space. If\nuser creates udmabuf with list.size == 0 then ubuf-\u003epagecount will be\nalso equal to zero; it causes kmalloc_array() to return ZERO_PTR.\n\nFix it by validating ubuf-\u003epagecount before passing it to\nkmalloc_array()."
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: udmabuf: validar ubuf-\u0026gt;pagecount Syzbot ha informado de un GPF en sg_alloc_append_table_from_pages(). El problema estaba en ubuf-\u0026gt;pages == ZERO_PTR. ubuf-\u0026gt;pagecount se calcula a partir de los argumentos pasados desde el espacio de usuario. Si el usuario crea udmabuf con list.size == 0, entonces ubuf-\u0026gt;pagecount tambi\u00e9n ser\u00e1 igual a cero; esto hace que kmalloc_array() devuelva ZERO_PTR. Arr\u00e9glelo validando ubuf-\u0026gt;pagecount antes de pasarlo a kmalloc_array()."
    }
  ],
  "id": "CVE-2021-47649",
  "lastModified": "2025-10-14T19:08:13.527",
  "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"
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  "published": "2025-02-26T06:37:06.687",
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  "vulnStatus": "Analyzed",
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          "value": "NVD-CWE-noinfo"
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      "source": "nvd@nist.gov",
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  ]
}


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