{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.1",
    "cveMetadata": {
        "cveId": "CVE-2021-46978",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2024-02-27T18:42:55.944Z",
        "datePublished": "2024-02-28T08:13:09.106Z",
        "dateUpdated": "2024-08-04T05:24:37.902Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2024-05-29T04:59:53.918Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: nVMX: Always make an attempt to map eVMCS after migration\n\nWhen enlightened VMCS is in use and nested state is migrated with\nvmx_get_nested_state()/vmx_set_nested_state() KVM can't map evmcs\npage right away: evmcs gpa is not 'struct kvm_vmx_nested_state_hdr'\nand we can't read it from VP assist page because userspace may decide\nto restore HV_X64_MSR_VP_ASSIST_PAGE after restoring nested state\n(and QEMU, for example, does exactly that). To make sure eVMCS is\nmapped /vmx_set_nested_state() raises KVM_REQ_GET_NESTED_STATE_PAGES\nrequest.\n\nCommit f2c7ef3ba955 (\"KVM: nSVM: cancel KVM_REQ_GET_NESTED_STATE_PAGES\non nested vmexit\") added KVM_REQ_GET_NESTED_STATE_PAGES clearing to\nnested_vmx_vmexit() to make sure MSR permission bitmap is not switched\nwhen an immediate exit from L2 to L1 happens right after migration (caused\nby a pending event, for example). Unfortunately, in the exact same\nsituation we still need to have eVMCS mapped so\nnested_sync_vmcs12_to_shadow() reflects changes in VMCS12 to eVMCS.\n\nAs a band-aid, restore nested_get_evmcs_page() when clearing\nKVM_REQ_GET_NESTED_STATE_PAGES in nested_vmx_vmexit(). The 'fix' is far\nfrom being ideal as we can't easily propagate possible failures and even if\nwe could, this is most likely already too late to do so. The whole\n'KVM_REQ_GET_NESTED_STATE_PAGES' idea for mapping eVMCS after migration\nseems to be fragile as we diverge too much from the 'native' path when\nvmptr loading happens on vmx_set_nested_state()."
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "arch/x86/kvm/vmx/nested.c"
                    ],
                    "versions": [
                        {
                            "version": "0faceb7d6dda",
                            "lessThan": "c8bf64e3fb77",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "f2c7ef3ba955",
                            "lessThan": "200a45649ab7",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "f2c7ef3ba955",
                            "lessThan": "bd0e8455b85b",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "f2c7ef3ba955",
                            "lessThan": "f5c7e8425f18",
                            "status": "affected",
                            "versionType": "git"
                        }
                    ]
                },
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "arch/x86/kvm/vmx/nested.c"
                    ],
                    "versions": [
                        {
                            "version": "5.11",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "5.11",
                            "status": "unaffected",
                            "versionType": "custom"
                        },
                        {
                            "version": "5.10.38",
                            "lessThanOrEqual": "5.10.*",
                            "status": "unaffected",
                            "versionType": "custom"
                        },
                        {
                            "version": "5.11.22",
                            "lessThanOrEqual": "5.11.*",
                            "status": "unaffected",
                            "versionType": "custom"
                        },
                        {
                            "version": "5.12.5",
                            "lessThanOrEqual": "5.12.*",
                            "status": "unaffected",
                            "versionType": "custom"
                        },
                        {
                            "version": "5.13",
                            "lessThanOrEqual": "*",
                            "status": "unaffected",
                            "versionType": "original_commit_for_fix"
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/c8bf64e3fb77cc19bad146fbe26651985b117194"
                },
                {
                    "url": "https://git.kernel.org/stable/c/200a45649ab7361bc80c70aebf7165b64f9a6c9f"
                },
                {
                    "url": "https://git.kernel.org/stable/c/bd0e8455b85b651a4c77de9616e307129b15aaa7"
                },
                {
                    "url": "https://git.kernel.org/stable/c/f5c7e8425f18fdb9bdb7d13340651d7876890329"
                }
            ],
            "title": "KVM: nVMX: Always make an attempt to map eVMCS after migration",
            "x_generator": {
                "engine": "bippy-a5840b7849dd"
            }
        },
        "adp": [
            {
                "title": "CISA ADP Vulnrichment",
                "metrics": [
                    {
                        "other": {
                            "type": "ssvc",
                            "content": {
                                "id": "CVE-2021-46978",
                                "role": "CISA Coordinator",
                                "options": [
                                    {
                                        "Exploitation": "none"
                                    },
                                    {
                                        "Automatable": "no"
                                    },
                                    {
                                        "Technical Impact": "partial"
                                    }
                                ],
                                "version": "2.0.3",
                                "timestamp": "2024-02-28T18:21:17.667516Z"
                            }
                        }
                    }
                ],
                "providerMetadata": {
                    "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
                    "shortName": "CISA-ADP",
                    "dateUpdated": "2024-06-04T17:13:12.156Z"
                }
            },
            {
                "providerMetadata": {
                    "orgId": "af854a3a-2127-422b-91ae-364da2661108",
                    "shortName": "CVE",
                    "dateUpdated": "2024-08-04T05:24:37.902Z"
                },
                "title": "CVE Program Container",
                "references": [
                    {
                        "url": "https://git.kernel.org/stable/c/c8bf64e3fb77cc19bad146fbe26651985b117194",
                        "tags": [
                            "x_transferred"
                        ]
                    },
                    {
                        "url": "https://git.kernel.org/stable/c/200a45649ab7361bc80c70aebf7165b64f9a6c9f",
                        "tags": [
                            "x_transferred"
                        ]
                    },
                    {
                        "url": "https://git.kernel.org/stable/c/bd0e8455b85b651a4c77de9616e307129b15aaa7",
                        "tags": [
                            "x_transferred"
                        ]
                    },
                    {
                        "url": "https://git.kernel.org/stable/c/f5c7e8425f18fdb9bdb7d13340651d7876890329",
                        "tags": [
                            "x_transferred"
                        ]
                    }
                ]
            }
        ]
    }
}