{
  "cveId": "CVE-2021-47140",
  "url": "https://patchblox.com/security/cve/CVE-2021-47140",
  "summary": "CVE-2021-47140 is fixed in linux on 1 platform, first by DEBIAN-CVE-2021-47140, released March 25, 2024. It is not reported as exploited. Patch Radar priority: Routine.",
  "title": "linux: In the Linux kernel, the following vulnerability has been resolved:  iommu/amd: Clear DMA ops when switching domain...",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  iommu/amd: Clear DMA ops when switching domain  Since commit 08a27c1c3ecf (\u0022iommu: Add support to change default domain of an iommu group\u0022) a user can switch a device between IOMMU and direct DMA through sysfs. This doesn\u0027t work for AMD IOMMU at the moment because dev-\u003Edma_ops is not cleared when switching from a DMA to an identity IOMMU domain. The DMA layer thus attempts to use the dma-iommu ops on an identity domain, causing an oops:    # echo 0000:00:05.0 \u003E /sys/sys/bus/pci/drivers/e1000e/unbind   # echo identity \u003E /sys/bus/pci/devices/0000:00:05.0/iommu_group/type   # echo 0000:00:05.0 \u003E /sys/sys/bus/pci/drivers/e1000e/bind    ...   BUG: kernel NULL pointer dereference, address: 0000000000000028    ...    Call Trace:     iommu_dma_alloc     e1000e_setup_tx_resources     e1000e_open  Since iommu_change_dev_def_domain() calls probe_finalize() again, clear the dma_ops there like Vt-d does.",
  "published": "2024-03-25T09:15:08Z",
  "severity": "medium",
  "cvss": 5.3,
  "cvssVector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
  "epss": 0.00603,
  "epssPercentile": 0.49137,
  "priority": "Routine",
  "priorityTier": 4,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 12.15 (bookworm)",
      "fixedVersion": "5.14.6-1",
      "fix": "DEBIAN-CVE-2021-47140",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2021-47140",
      "released": "2024-03-25T09:15:08Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "5.14.6-1",
      "fix": "DEBIAN-CVE-2021-47140",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2021-47140",
      "released": "2024-03-25T09:15:08Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "5.14.6-1",
      "fix": "DEBIAN-CVE-2021-47140",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2021-47140",
      "released": "2024-03-25T09:15:08Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T19:12:23Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}