{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "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": "2026-05-23T15:18:50.711Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-05-23T15:18:50.711Z" }, "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": "0faceb7d6dda6f370ff1fa0464d7180f7e5cb417", "lessThan": "c8bf64e3fb77cc19bad146fbe26651985b117194", "status": "affected", "versionType": "git" }, { "version": "f2c7ef3ba9556d62a7e2bb23b563c6510007d55c", "lessThan": "200a45649ab7361bc80c70aebf7165b64f9a6c9f", "status": "affected", "versionType": "git" }, { "version": "f2c7ef3ba9556d62a7e2bb23b563c6510007d55c", "lessThan": "bd0e8455b85b651a4c77de9616e307129b15aaa7", "status": "affected", "versionType": "git" }, { "version": "f2c7ef3ba9556d62a7e2bb23b563c6510007d55c", "lessThan": "f5c7e8425f18fdb9bdb7d13340651d7876890329", "status": "affected", "versionType": "git" }, { "version": "5.10.13", "lessThan": "5.10.38", "status": "affected", "versionType": "semver" } ] }, { "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": "semver" }, { "version": "5.10.38", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.11.22", "lessThanOrEqual": "5.11.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.12.5", "lessThanOrEqual": "5.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.13", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10.13", "versionEndExcluding": "5.10.38" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11", "versionEndExcluding": "5.11.22" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11", "versionEndExcluding": "5.12.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11", "versionEndExcluding": "5.13" } ] } ] } ], "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-1.2.0" } }, "adp": [ { "problemTypes": [ { "descriptions": [ { "type": "CWE", "lang": "en", "description": "CWE-noinfo Not enough information" } ] } ], "affected": [ { "vendor": "linux", "product": "linux_kernel", "cpes": [ "cpe:2.3:o:linux:linux_kernel:-:*:*:*:*:*:*:*" ], "defaultStatus": "unknown", "versions": [ { "version": "0faceb7d6dda", "status": "affected", "lessThan": "c8bf64e3fb77", "versionType": "git" }, { "version": "f2c7ef3ba955", "status": "affected", "lessThan": "200a45649ab7", "versionType": "git" }, { "version": "f2c7ef3ba955", "status": "affected", "lessThan": "bd0e8455b85b", "versionType": "git" }, { "version": "f2c7ef3ba955", "status": "affected", "lessThan": "f5c7e8425f18", "versionType": "git" }, { "version": "5.11", "status": "affected" }, { "version": "0", "status": "affected", "lessThan": "5.11*", "versionType": "semver" }, { "version": "5.10.38", "status": "affected", "lessThanOrEqual": "5.11*", "versionType": "semver" }, { "version": "5.12.5", "status": "affected", "lessThanOrEqual": "5.12*", "versionType": "semver" }, { "version": "5.13", "status": "affected", "lessThanOrEqual": "*", "versionType": "semver" } ] } ], "metrics": [ { "cvssV3_1": { "scope": "UNCHANGED", "version": "3.1", "baseScore": 7.8, "attackVector": "LOCAL", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "HIGH" } }, { "other": { "type": "ssvc", "content": { "timestamp": "2024-11-04T17:39:28.108559Z", "id": "CVE-2021-46978", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "total" } ], "role": "CISA Coordinator", "version": "2.0.3" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-11-04T17:46:50.654Z" } }, { "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" ] } ] } ] } }