FKIE_CVE-2021-47108

Vulnerability from fkie_nvd - Published: 2024-03-04 19:15 - Updated: 2026-06-17 04:16
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: drm/mediatek: hdmi: Perform NULL pointer check for mtk_hdmi_conf In commit 41ca9caaae0b ("drm/mediatek: hdmi: Add check for CEA modes only") a check for CEA modes was added to function mtk_hdmi_bridge_mode_valid() in order to address possible issues on MT8167; moreover, with commit c91026a938c2 ("drm/mediatek: hdmi: Add optional limit on maximal HDMI mode clock") another similar check was introduced. Unfortunately though, at the time of writing, MT8173 does not provide any mtk_hdmi_conf structure and this is crashing the kernel with NULL pointer upon entering mtk_hdmi_bridge_mode_valid(), which happens as soon as a HDMI cable gets plugged in. To fix this regression, add a NULL pointer check for hdmi->conf in the said function, restoring HDMI functionality and avoiding NULL pointer kernel panics.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/3b8e19a0aa3933a785be9f1541afd8d398c4ec69Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/71d07ebc5000b9c1d140e99e7493b0bafa954776Patch
af854a3a-2127-422b-91ae-364da2661108https://git.kernel.org/stable/c/3b8e19a0aa3933a785be9f1541afd8d398c4ec69Patch
af854a3a-2127-422b-91ae-364da2661108https://git.kernel.org/stable/c/71d07ebc5000b9c1d140e99e7493b0bafa954776Patch
Impacted products
Vendor Product Version
linux linux_kernel *
linux linux_kernel 5.16
linux linux_kernel 5.16
linux linux_kernel 5.16
linux linux_kernel 5.16
linux linux_kernel 5.16
linux linux_kernel 5.16
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/gpu/drm/mediatek/mtk_hdmi.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "71d07ebc5000b9c1d140e99e7493b0bafa954776",
              "status": "affected",
              "version": "41ca9caaae0bfc959b22dbcd59d88a7107707e17",
              "versionType": "git"
            },
            {
              "lessThan": "3b8e19a0aa3933a785be9f1541afd8d398c4ec69",
              "status": "affected",
              "version": "41ca9caaae0bfc959b22dbcd59d88a7107707e17",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/gpu/drm/mediatek/mtk_hdmi.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.14"
            },
            {
              "lessThan": "5.14",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.12",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "5.16",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
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              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "901A6B90-4B30-4E61-9B88-844D6E11AE47",
              "versionEndExcluding": "5.15.12",
              "versionStartIncluding": "5.14",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:5.16:rc1:*:*:*:*:*:*",
              "matchCriteriaId": "357AA433-37E8-4323-BFB2-3038D6E4B414",
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          "negate": false,
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  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/mediatek: hdmi: Perform NULL pointer check for mtk_hdmi_conf\n\nIn commit 41ca9caaae0b\n(\"drm/mediatek: hdmi: Add check for CEA modes only\") a check\nfor CEA modes was added to function mtk_hdmi_bridge_mode_valid()\nin order to address possible issues on MT8167;\nmoreover, with commit c91026a938c2\n(\"drm/mediatek: hdmi: Add optional limit on maximal HDMI mode clock\")\nanother similar check was introduced.\n\nUnfortunately though, at the time of writing, MT8173 does not provide\nany mtk_hdmi_conf structure and this is crashing the kernel with NULL\npointer upon entering mtk_hdmi_bridge_mode_valid(), which happens as\nsoon as a HDMI cable gets plugged in.\n\nTo fix this regression, add a NULL pointer check for hdmi-\u003econf in the\nsaid function, restoring HDMI functionality and avoiding NULL pointer\nkernel panics."
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, se resolvi\u00f3 la siguiente vulnerabilidad: drm/mediatek: hdmi: realice una verificaci\u00f3n de puntero NULL para mtk_hdmi_conf En el commit 41ca9caaae0b (\"drm/mediatek: hdmi: agregue verificaci\u00f3n solo para modos CEA\") se agreg\u00f3 una verificaci\u00f3n para los modos CEA funcionar mtk_hdmi_bridge_mode_valid() para solucionar posibles problemas en MT8167; Adem\u00e1s, con el commit c91026a938c2 (\"drm/mediatek: hdmi: Agregar l\u00edmite opcional en el reloj m\u00e1ximo en modo HDMI\") se introdujo otra verificaci\u00f3n similar. Desafortunadamente, al momento de escribir este art\u00edculo, MT8173 no proporciona ninguna estructura mtk_hdmi_conf y esto bloquea el kernel con un puntero NULL al ingresar a mtk_hdmi_bridge_mode_valid(), lo que sucede tan pronto como se conecta un cable HDMI. Para solucionar esta regresi\u00f3n, agregue un El puntero NULL comprueba hdmi-\u0026gt;conf en dicha funci\u00f3n, restaurando la funcionalidad HDMI y evitando p\u00e1nicos del kernel del puntero NULL."
    }
  ],
  "id": "CVE-2021-47108",
  "lastModified": "2026-06-17T04:16:30.537",
  "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"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2021-47108",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2024-06-26T20:37:26.989775Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2024-03-04T19:15:18.837",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/3b8e19a0aa3933a785be9f1541afd8d398c4ec69"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/71d07ebc5000b9c1d140e99e7493b0bafa954776"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/3b8e19a0aa3933a785be9f1541afd8d398c4ec69"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/71d07ebc5000b9c1d140e99e7493b0bafa954776"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-476"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}



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