{
  "id": "CVE-2021-47439",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2024-05-22T07:15:09.163",
  "lastModified": "2024-11-21T06:36:08.737",
  "vulnStatus": "Awaiting Analysis",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: dsa: microchip: Added the condition for scheduling ksz_mib_read_work\n\nWhen the ksz module is installed and removed using rmmod, kernel crashes\nwith null pointer dereferrence error. During rmmod, ksz_switch_remove\nfunction tries to cancel the mib_read_workqueue using\ncancel_delayed_work_sync routine and unregister switch from dsa.\n\nDuring dsa_unregister_switch it calls ksz_mac_link_down, which in turn\nreschedules the workqueue since mib_interval is non-zero.\nDue to which queue executed after mib_interval and it tries to access\ndp->slave. But the slave is unregistered in the ksz_switch_remove\nfunction. Hence kernel crashes.\n\nTo avoid this crash, before canceling the workqueue, resetted the\nmib_interval to 0.\n\nv1 -> v2:\n-Removed the if condition in ksz_mib_read_work"
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, se resolvi\u00f3 la siguiente vulnerabilidad: net: dsa: microchip: se agreg\u00f3 la condici\u00f3n para programar ksz_mib_read_work Cuando el m\u00f3dulo ksz se instala y elimina usando rmmod, el kernel falla con un error de desreferencia de puntero nulo. Durante rmmod, la funci\u00f3n ksz_switch_remove intenta cancelar mib_read_workqueue usando la rutina cancel_delayed_work_sync y cancelar el registro del conmutador de dsa. Durante dsa_unregister_switch llama a ksz_mac_link_down, que a su vez reprograma la cola de trabajo ya que mib_interval no es cero. Debido a qu\u00e9 cola se ejecut\u00f3 despu\u00e9s de mib_interval e intenta acceder a dp->slave. Pero el esclavo no est\u00e1 registrado en la funci\u00f3n ksz_switch_remove. Por lo tanto, el kernel falla. Para evitar este bloqueo, antes de cancelar la cola de trabajo, restableci\u00f3 mib_interval a 0. v1 -> v2: -Se elimin\u00f3 la condici\u00f3n if en ksz_mib_read_work"
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "baseScore": 5.5,
          "baseSeverity": "MEDIUM",
          "attackVector": "LOCAL",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 3.6
      }
    ]
  },
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/383239a33cf29ebee9ce0d4e0e5c900b77a16148",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/ef1100ef20f29aec4e62abeccdb5bdbebba1e378",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/f2e1de075018cf71bcd7d628e9f759cb8540b0c3",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/383239a33cf29ebee9ce0d4e0e5c900b77a16148",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://git.kernel.org/stable/c/ef1100ef20f29aec4e62abeccdb5bdbebba1e378",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://git.kernel.org/stable/c/f2e1de075018cf71bcd7d628e9f759cb8540b0c3",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    }
  ]
}