FKIE_CVE-2021-47282

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: spi: bcm2835: Fix out-of-bounds access with more than 4 slaves Commit 571e31fa60b3 ("spi: bcm2835: Cache CS register value for ->prepare_message()") limited the number of slaves to 3 at compile-time. The limitation was necessitated by a statically-sized array prepare_cs[] in the driver private data which contains a per-slave register value. The commit sought to enforce the limitation at run-time by setting the controller's num_chipselect to 3: Slaves with a higher chipselect are rejected by spi_add_device(). However the commit neglected that num_chipselect only limits the number of *native* chipselects. If GPIO chipselects are specified in the device tree for more than 3 slaves, num_chipselect is silently raised by of_spi_get_gpio_numbers() and the result are out-of-bounds accesses to the statically-sized array prepare_cs[]. As a bandaid fix which is backportable to stable, raise the number of allowed slaves to 24 (which "ought to be enough for anybody"), enforce the limitation on slave ->setup and revert num_chipselect to 3 (which is the number of native chipselects supported by the controller). An upcoming for-next commit will allow an arbitrary number of slaves.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/01415ff85a24308059e06ca3e97fd7bf75648690Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/13817d466eb8713a1ffd254f537402f091d48444Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/82a8ffba54d31e97582051cb56ba1f988018681ePatch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/b5502580cf958b094f3b69dfe4eece90eae01fbcPatch
af854a3a-2127-422b-91ae-364da2661108https://git.kernel.org/stable/c/01415ff85a24308059e06ca3e97fd7bf75648690Patch
af854a3a-2127-422b-91ae-364da2661108https://git.kernel.org/stable/c/13817d466eb8713a1ffd254f537402f091d48444Patch
af854a3a-2127-422b-91ae-364da2661108https://git.kernel.org/stable/c/82a8ffba54d31e97582051cb56ba1f988018681ePatch
af854a3a-2127-422b-91ae-364da2661108https://git.kernel.org/stable/c/b5502580cf958b094f3b69dfe4eece90eae01fbcPatch
Impacted products
Vendor Product Version
linux linux_kernel *
linux linux_kernel *
linux linux_kernel *
linux linux_kernel 5.13
linux linux_kernel 5.13
linux linux_kernel 5.13
linux linux_kernel 5.13
linux linux_kernel 5.13
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/spi/spi-bcm2835.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "b5502580cf958b094f3b69dfe4eece90eae01fbc",
              "status": "affected",
              "version": "571e31fa60b3697d5db26140e16d5c45c51c9815",
              "versionType": "git"
            },
            {
              "lessThan": "82a8ffba54d31e97582051cb56ba1f988018681e",
              "status": "affected",
              "version": "571e31fa60b3697d5db26140e16d5c45c51c9815",
              "versionType": "git"
            },
            {
              "lessThan": "01415ff85a24308059e06ca3e97fd7bf75648690",
              "status": "affected",
              "version": "571e31fa60b3697d5db26140e16d5c45c51c9815",
              "versionType": "git"
            },
            {
              "lessThan": "13817d466eb8713a1ffd254f537402f091d48444",
              "status": "affected",
              "version": "571e31fa60b3697d5db26140e16d5c45c51c9815",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/spi/spi-bcm2835.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.4"
            },
            {
              "lessThan": "5.4",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.4.*",
              "status": "unaffected",
              "version": "5.4.126",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.44",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.12.*",
              "status": "unaffected",
              "version": "5.12.11",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "5.13",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "6D23A3FF-8CE4-41A1-9E6A-8138FDC413F6",
              "versionEndExcluding": "5.4.126",
              "versionStartIncluding": "5.4",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "DA547B08-9D25-467B-AD0D-8460FE4EE70D",
              "versionEndExcluding": "5.10.44",
              "versionStartIncluding": "5.5",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "F914A757-FAFD-407E-9031-21F66635D5EA",
              "versionEndExcluding": "5.12.11",
              "versionStartIncluding": "5.11",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:5.13:rc1:*:*:*:*:*:*",
              "matchCriteriaId": "0CBAD0FC-C281-4666-AB2F-F8E6E1165DF7",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:5.13:rc2:*:*:*:*:*:*",
              "matchCriteriaId": "96AC23B2-D46A-49D9-8203-8E1BEDCA8532",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:5.13:rc3:*:*:*:*:*:*",
              "matchCriteriaId": "DA610E30-717C-4700-9F77-A3C9244F3BFD",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:5.13:rc4:*:*:*:*:*:*",
              "matchCriteriaId": "1ECD33F5-85BE-430B-8F86-8D7BD560311D",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:5.13:rc5:*:*:*:*:*:*",
              "matchCriteriaId": "CF351855-2437-4CF5-AD7C-BDFA51F27683",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nspi: bcm2835: Fix out-of-bounds access with more than 4 slaves\n\nCommit 571e31fa60b3 (\"spi: bcm2835: Cache CS register value for\n-\u003eprepare_message()\") limited the number of slaves to 3 at compile-time.\nThe limitation was necessitated by a statically-sized array prepare_cs[]\nin the driver private data which contains a per-slave register value.\n\nThe commit sought to enforce the limitation at run-time by setting the\ncontroller\u0027s num_chipselect to 3:  Slaves with a higher chipselect are\nrejected by spi_add_device().\n\nHowever the commit neglected that num_chipselect only limits the number\nof *native* chipselects.  If GPIO chipselects are specified in the\ndevice tree for more than 3 slaves, num_chipselect is silently raised by\nof_spi_get_gpio_numbers() and the result are out-of-bounds accesses to\nthe statically-sized array prepare_cs[].\n\nAs a bandaid fix which is backportable to stable, raise the number of\nallowed slaves to 24 (which \"ought to be enough for anybody\"), enforce\nthe limitation on slave -\u003esetup and revert num_chipselect to 3 (which is\nthe number of native chipselects supported by the controller).\nAn upcoming for-next commit will allow an arbitrary number of slaves."
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: spi: bcm2835: corrige el acceso fuera de los l\u00edmites con m\u00e1s de 4 esclavos. La confirmaci\u00f3n 571e31fa60b3 (\"spi: bcm2835: valor de registro CS de cach\u00e9 para -\u0026gt;prepare_message()\") limit\u00f3 el n\u00famero de esclavos a 3 en tiempo de compilaci\u00f3n. La limitaci\u00f3n fue necesaria por una matriz de tama\u00f1o est\u00e1tico prepare_cs[] en los datos privados del controlador que contiene un valor de registro por esclavo. La confirmaci\u00f3n buscaba hacer cumplir la limitaci\u00f3n en tiempo de ejecuci\u00f3n estableciendo num_chipselect del controlador en 3: spi_add_device() rechaza los esclavos con una selecci\u00f3n de chip m\u00e1s alta. Sin embargo, la confirmaci\u00f3n omiti\u00f3 que num_chipselect solo limita el n\u00famero de selecciones de chips *nativas*. Si se especifican selecciones de chips GPIO en el \u00e1rbol de dispositivos para m\u00e1s de 3 esclavos, of_spi_get_gpio_numbers() genera silenciosamente num_chipselect y el resultado son accesos fuera de los l\u00edmites a la matriz de tama\u00f1o est\u00e1tico prepare_cs[]. Como soluci\u00f3n curita que se puede volver a transferir a estable, aumente la cantidad de esclavos permitidos a 24 (lo que \"deber\u00eda ser suficiente para cualquiera\"), aplique la limitaci\u00f3n en esclavo -\u0026gt; configuraci\u00f3n y revierta num_chipselect a 3 (que es la cantidad de nativos selecciones de chips admitidas por el controlador). Una pr\u00f3xima confirmaci\u00f3n para la pr\u00f3xima permitir\u00e1 una cantidad arbitraria de esclavos."
    }
  ],
  "id": "CVE-2021-47282",
  "lastModified": "2026-06-17T04:17:05.830",
  "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": "nvd@nist.gov",
        "type": "Primary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2021-47282",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2024-05-23T17:10:17.644618Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2024-05-21T15:15:16.430",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/01415ff85a24308059e06ca3e97fd7bf75648690"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/13817d466eb8713a1ffd254f537402f091d48444"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/82a8ffba54d31e97582051cb56ba1f988018681e"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/b5502580cf958b094f3b69dfe4eece90eae01fbc"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/01415ff85a24308059e06ca3e97fd7bf75648690"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/13817d466eb8713a1ffd254f537402f091d48444"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/82a8ffba54d31e97582051cb56ba1f988018681e"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/b5502580cf958b094f3b69dfe4eece90eae01fbc"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-787"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

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.