{
    "data_version": "4.0",
    "data_type": "CVE",
    "data_format": "MITRE",
    "CVE_data_meta": {
        "ID": "CVE-2021-47140",
        "ASSIGNER": "cve@kernel.org",
        "STATE": "PUBLIC"
    },
    "description": {
        "description_data": [
            {
                "lang": "eng",
                "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."
            }
        ]
    },
    "problemtype": {
        "problemtype_data": [
            {
                "description": [
                    {
                        "lang": "eng",
                        "value": "n/a"
                    }
                ]
            }
        ]
    },
    "affects": {
        "vendor": {
            "vendor_data": [
                {
                    "vendor_name": "Linux",
                    "product": {
                        "product_data": [
                            {
                                "product_name": "Linux",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "<",
                                            "version_name": "08a27c1c3ecf",
                                            "version_value": "f3f2cf46291a"
                                        },
                                        {
                                            "version_value": "not down converted",
                                            "x_cve_json_5_version_data": {
                                                "versions": [
                                                    {
                                                        "version": "5.11",
                                                        "status": "affected"
                                                    },
                                                    {
                                                        "version": "0",
                                                        "lessThan": "5.11",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "5.12.9",
                                                        "lessThanOrEqual": "5.12.*",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "5.13",
                                                        "lessThanOrEqual": "*",
                                                        "status": "unaffected",
                                                        "versionType": "original_commit_for_fix"
                                                    }
                                                ],
                                                "defaultStatus": "affected"
                                            }
                                        }
                                    ]
                                }
                            }
                        ]
                    }
                }
            ]
        }
    },
    "references": {
        "reference_data": [
            {
                "url": "https://git.kernel.org/stable/c/f3f2cf46291a693eab21adb94171b0128c2a9ec1",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/f3f2cf46291a693eab21adb94171b0128c2a9ec1"
            },
            {
                "url": "https://git.kernel.org/stable/c/d6177a6556f853785867e2ec6d5b7f4906f0d809",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/d6177a6556f853785867e2ec6d5b7f4906f0d809"
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