{
  "id": "CVE-2021-47140",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2024-03-25T09:15:08.740",
  "lastModified": "2025-03-19T16:28:16.000",
  "vulnStatus": "Analyzed",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\niommu/amd: Clear DMA ops when switching domain\n\nSince commit 08a27c1c3ecf (\"iommu: Add support to change default domain\nof an iommu group\") a user can switch a device between IOMMU and direct\nDMA through sysfs. This doesn't work for AMD IOMMU at the moment because\ndev->dma_ops is not cleared when switching from a DMA to an identity\nIOMMU domain. The DMA layer thus attempts to use the dma-iommu ops on an\nidentity domain, causing an oops:\n\n  # echo 0000:00:05.0 > /sys/sys/bus/pci/drivers/e1000e/unbind\n  # echo identity > /sys/bus/pci/devices/0000:00:05.0/iommu_group/type\n  # echo 0000:00:05.0 > /sys/sys/bus/pci/drivers/e1000e/bind\n   ...\n  BUG: kernel NULL pointer dereference, address: 0000000000000028\n   ...\n   Call Trace:\n    iommu_dma_alloc\n    e1000e_setup_tx_resources\n    e1000e_open\n\nSince iommu_change_dev_def_domain() calls probe_finalize() again, clear\nthe dma_ops there like Vt-d does."
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: iommu/amd: borra las operaciones de DMA al cambiar de dominio. Desde el commit 08a27c1c3ecf (\"iommu: agrega soporte para cambiar el dominio predeterminado de un grupo iommu\"), un usuario puede cambiar un dispositivo entre IOMMU y DMA directo a trav\u00e9s de sysfs. Esto no funciona para AMD IOMMU en este momento porque dev->dma_ops no se borra al cambiar de un DMA a un dominio IOMMU de identidad. Por lo tanto, la capa DMA intenta utilizar las operaciones dma-iommu en un dominio de identidad, lo que provoca un error: # echo 0000:00:05.0 > /sys/sys/bus/pci/drivers/e1000e/unbind # echo Identity > /sys/ bus/pci/devices/0000:00:05.0/iommu_group/type # echo 0000:00:05.0 > /sys/sys/bus/pci/drivers/e1000e/bind ... ERROR: desreferencia del puntero NULL del kernel, direcci\u00f3n: 0000000000000028 ... Seguimiento de llamadas: iommu_dma_alloc e1000e_setup_tx_resources e1000e_open Dado que iommu_change_dev_def_domain() llama a probe_finalize() nuevamente, borre dma_ops all\u00ed como lo hace Vt-d."
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
          "baseScore": 5.3,
          "baseSeverity": "MEDIUM",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "availabilityImpact": "LOW"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 1.4
      }
    ]
  },
  "weaknesses": [
    {
      "source": "nvd@nist.gov",
      "type": "Primary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-476"
        }
      ]
    }
  ],
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          "operator": "OR",
          "negate": false,
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      "url": "https://git.kernel.org/stable/c/d6177a6556f853785867e2ec6d5b7f4906f0d809",
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