{"dataType": "CVE_RECORD", "dataVersion": "5.1", "cveMetadata": {"cveId": "CVE-2021-47092", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-02-29T22:33:44.300Z", "datePublished": "2024-03-04T18:10:40.037Z", "dateUpdated": "2024-11-04T11:59:15.110Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2024-11-04T11:59:15.110Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: VMX: Always clear vmx->fail on emulation_required\n\nRevert a relatively recent change that set vmx->fail if the vCPU is in L2\nand emulation_required is true, as that behavior is completely bogus.\nSetting vmx->fail and synthesizing a VM-Exit is contradictory and wrong:\n\n (a) it's impossible to have both a VM-Fail and VM-Exit\n (b) vmcs.EXIT_REASON is not modified on VM-Fail\n (c) emulation_required refers to guest state and guest state checks are\n always VM-Exits, not VM-Fails.\n\nFor KVM specifically, emulation_required is handled before nested exits\nin __vmx_handle_exit(), thus setting vmx->fail has no immediate effect,\ni.e. KVM calls into handle_invalid_guest_state() and vmx->fail is ignored.\nSetting vmx->fail can ultimately result in a WARN in nested_vmx_vmexit()\nfiring when tearing down the VM as KVM never expects vmx->fail to be set\nwhen L2 is active, KVM always reflects those errors into L1.\n\n ------------[ cut here ]------------\n WARNING: CPU: 0 PID: 21158 at arch/x86/kvm/vmx/nested.c:4548\n nested_vmx_vmexit+0x16bd/0x17e0\n arch/x86/kvm/vmx/nested.c:4547\n Modules linked in:\n CPU: 0 PID: 21158 Comm: syz-executor.1 Not tainted 5.16.0-rc3-syzkaller #0\n Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011\n RIP: 0010:nested_vmx_vmexit+0x16bd/0x17e0 arch/x86/kvm/vmx/nested.c:4547\n Code: <0f> 0b e9 2e f8 ff ff e8 57 b3 5d 00 0f 0b e9 00 f1 ff ff 89 e9 80\n Call Trace:\n vmx_leave_nested arch/x86/kvm/vmx/nested.c:6220 [inline]\n nested_vmx_free_vcpu+0x83/0xc0 arch/x86/kvm/vmx/nested.c:330\n vmx_free_vcpu+0x11f/0x2a0 arch/x86/kvm/vmx/vmx.c:6799\n kvm_arch_vcpu_destroy+0x6b/0x240 arch/x86/kvm/x86.c:10989\n kvm_vcpu_destroy+0x29/0x90 arch/x86/kvm/../../../virt/kvm/kvm_main.c:441\n kvm_free_vcpus arch/x86/kvm/x86.c:11426 [inline]\n kvm_arch_destroy_vm+0x3ef/0x6b0 arch/x86/kvm/x86.c:11545\n kvm_destroy_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:1189 [inline]\n kvm_put_kvm+0x751/0xe40 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1220\n kvm_vcpu_release+0x53/0x60 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3489\n __fput+0x3fc/0x870 fs/file_table.c:280\n task_work_run+0x146/0x1c0 kernel/task_work.c:164\n exit_task_work include/linux/task_work.h:32 [inline]\n do_exit+0x705/0x24f0 kernel/exit.c:832\n do_group_exit+0x168/0x2d0 kernel/exit.c:929\n get_signal+0x1740/0x2120 kernel/signal.c:2852\n arch_do_signal_or_restart+0x9c/0x730 arch/x86/kernel/signal.c:868\n handle_signal_work kernel/entry/common.c:148 [inline]\n exit_to_user_mode_loop kernel/entry/common.c:172 [inline]\n exit_to_user_mode_prepare+0x191/0x220 kernel/entry/common.c:207\n __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]\n syscall_exit_to_user_mode+0x2e/0x70 kernel/entry/common.c:300\n do_syscall_64+0x53/0xd0 arch/x86/entry/common.c:86\n entry_SYSCALL_64_after_hwframe+0x44/0xae"}], "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/vmx.c"], "versions": [{"version": "c8607e4a086f", "lessThan": "e4e4e7cb2298", "status": "affected", "versionType": "git"}, {"version": "c8607e4a086f", "lessThan": "a80dfc025924", "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/vmx.c"], "versions": [{"version": "5.15", "status": "affected"}, {"version": "0", "lessThan": "5.15", "status": "unaffected", "versionType": "semver"}, {"version": "5.15.12", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver"}, {"version": "5.16", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "references": [{"url": "https://git.kernel.org/stable/c/e4e4e7cb229821cd215031abc47efdab5486a67c"}, {"url": "https://git.kernel.org/stable/c/a80dfc025924024d2c61a4c1b8ef62b2fce76a04"}], "title": "KVM: VMX: Always clear vmx->fail on emulation_required", "x_generator": {"engine": "bippy-9e1c9544281a"}}, "adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2021-47092", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2024-03-05T16:06:27.446823Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-06-04T17:15:07.372Z"}}, {"providerMetadata": {"orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-04T05:24:39.809Z"}, "title": "CVE Program Container", "references": [{"url": "https://git.kernel.org/stable/c/e4e4e7cb229821cd215031abc47efdab5486a67c", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/a80dfc025924024d2c61a4c1b8ef62b2fce76a04", "tags": ["x_transferred"]}]}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CVE Program Container", "references": [{"url": "https://git.kernel.org/stable/c/e4e4e7cb229821cd215031abc47efdab5486a67c", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/a80dfc025924024d2c61a4c1b8ef62b2fce76a04", "tags": ["x_transferred"]}], "providerMetadata": {"orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-04T05:24:39.809Z"}}, {"metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2021-47092", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2024-03-05T16:06:27.446823Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-05-23T19:01:15.263Z"}, "title": "CISA ADP Vulnrichment"}], "cna": {"title": "KVM: VMX: Always clear vmx->fail on emulation_required", "affected": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "c8607e4a086f", "lessThan": "e4e4e7cb2298", "versionType": "git"}, {"status": "affected", "version": "c8607e4a086f", "lessThan": "a80dfc025924", "versionType": "git"}], "programFiles": ["arch/x86/kvm/vmx/vmx.c"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "5.15"}, {"status": "unaffected", "version": "0", "lessThan": "5.15", "versionType": "semver"}, {"status": "unaffected", "version": "5.15.12", "versionType": "semver", "lessThanOrEqual": "5.15.*"}, {"status": "unaffected", "version": "5.16", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["arch/x86/kvm/vmx/vmx.c"], "defaultStatus": "affected"}], "references": [{"url": "https://git.kernel.org/stable/c/e4e4e7cb229821cd215031abc47efdab5486a67c"}, {"url": "https://git.kernel.org/stable/c/a80dfc025924024d2c61a4c1b8ef62b2fce76a04"}], "x_generator": {"engine": "bippy-9e1c9544281a"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: VMX: Always clear vmx->fail on emulation_required\n\nRevert a relatively recent change that set vmx->fail if the vCPU is in L2\nand emulation_required is true, as that behavior is completely bogus.\nSetting vmx->fail and synthesizing a VM-Exit is contradictory and wrong:\n\n (a) it's impossible to have both a VM-Fail and VM-Exit\n (b) vmcs.EXIT_REASON is not modified on VM-Fail\n (c) emulation_required refers to guest state and guest state checks are\n always VM-Exits, not VM-Fails.\n\nFor KVM specifically, emulation_required is handled before nested exits\nin __vmx_handle_exit(), thus setting vmx->fail has no immediate effect,\ni.e. KVM calls into handle_invalid_guest_state() and vmx->fail is ignored.\nSetting vmx->fail can ultimately result in a WARN in nested_vmx_vmexit()\nfiring when tearing down the VM as KVM never expects vmx->fail to be set\nwhen L2 is active, KVM always reflects those errors into L1.\n\n ------------[ cut here ]------------\n WARNING: CPU: 0 PID: 21158 at arch/x86/kvm/vmx/nested.c:4548\n nested_vmx_vmexit+0x16bd/0x17e0\n arch/x86/kvm/vmx/nested.c:4547\n Modules linked in:\n CPU: 0 PID: 21158 Comm: syz-executor.1 Not tainted 5.16.0-rc3-syzkaller #0\n Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011\n RIP: 0010:nested_vmx_vmexit+0x16bd/0x17e0 arch/x86/kvm/vmx/nested.c:4547\n Code: <0f> 0b e9 2e f8 ff ff e8 57 b3 5d 00 0f 0b e9 00 f1 ff ff 89 e9 80\n Call Trace:\n vmx_leave_nested arch/x86/kvm/vmx/nested.c:6220 [inline]\n nested_vmx_free_vcpu+0x83/0xc0 arch/x86/kvm/vmx/nested.c:330\n vmx_free_vcpu+0x11f/0x2a0 arch/x86/kvm/vmx/vmx.c:6799\n kvm_arch_vcpu_destroy+0x6b/0x240 arch/x86/kvm/x86.c:10989\n kvm_vcpu_destroy+0x29/0x90 arch/x86/kvm/../../../virt/kvm/kvm_main.c:441\n kvm_free_vcpus arch/x86/kvm/x86.c:11426 [inline]\n kvm_arch_destroy_vm+0x3ef/0x6b0 arch/x86/kvm/x86.c:11545\n kvm_destroy_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:1189 [inline]\n kvm_put_kvm+0x751/0xe40 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1220\n kvm_vcpu_release+0x53/0x60 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3489\n __fput+0x3fc/0x870 fs/file_table.c:280\n task_work_run+0x146/0x1c0 kernel/task_work.c:164\n exit_task_work include/linux/task_work.h:32 [inline]\n do_exit+0x705/0x24f0 kernel/exit.c:832\n do_group_exit+0x168/0x2d0 kernel/exit.c:929\n get_signal+0x1740/0x2120 kernel/signal.c:2852\n arch_do_signal_or_restart+0x9c/0x730 arch/x86/kernel/signal.c:868\n handle_signal_work kernel/entry/common.c:148 [inline]\n exit_to_user_mode_loop kernel/entry/common.c:172 [inline]\n exit_to_user_mode_prepare+0x191/0x220 kernel/entry/common.c:207\n __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]\n syscall_exit_to_user_mode+0x2e/0x70 kernel/entry/common.c:300\n do_syscall_64+0x53/0xd0 arch/x86/entry/common.c:86\n entry_SYSCALL_64_after_hwframe+0x44/0xae"}], "providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2024-11-04T11:59:15.110Z"}}}, "cveMetadata": {"cveId": "CVE-2021-47092", "state": "PUBLISHED", "dateUpdated": "2024-11-04T11:59:15.110Z", "dateReserved": "2024-02-29T22:33:44.300Z", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "datePublished": "2024-03-04T18:10:40.037Z", "assignerShortName": "Linux"}, "dataVersion": "5.1"}

{"cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: VMX: Always clear vmx->fail on emulation_required\n\nRevert a relatively recent change that set vmx->fail if the vCPU is in L2\nand emulation_required is true, as that behavior is completely bogus.\nSetting vmx->fail and synthesizing a VM-Exit is contradictory and wrong:\n\n (a) it's impossible to have both a VM-Fail and VM-Exit\n (b) vmcs.EXIT_REASON is not modified on VM-Fail\n (c) emulation_required refers to guest state and guest state checks are\n always VM-Exits, not VM-Fails.\n\nFor KVM specifically, emulation_required is handled before nested exits\nin __vmx_handle_exit(), thus setting vmx->fail has no immediate effect,\ni.e. KVM calls into handle_invalid_guest_state() and vmx->fail is ignored.\nSetting vmx->fail can ultimately result in a WARN in nested_vmx_vmexit()\nfiring when tearing down the VM as KVM never expects vmx->fail to be set\nwhen L2 is active, KVM always reflects those errors into L1.\n\n ------------[ cut here ]------------\n WARNING: CPU: 0 PID: 21158 at arch/x86/kvm/vmx/nested.c:4548\n nested_vmx_vmexit+0x16bd/0x17e0\n arch/x86/kvm/vmx/nested.c:4547\n Modules linked in:\n CPU: 0 PID: 21158 Comm: syz-executor.1 Not tainted 5.16.0-rc3-syzkaller #0\n Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011\n RIP: 0010:nested_vmx_vmexit+0x16bd/0x17e0 arch/x86/kvm/vmx/nested.c:4547\n Code: <0f> 0b e9 2e f8 ff ff e8 57 b3 5d 00 0f 0b e9 00 f1 ff ff 89 e9 80\n Call Trace:\n vmx_leave_nested arch/x86/kvm/vmx/nested.c:6220 [inline]\n nested_vmx_free_vcpu+0x83/0xc0 arch/x86/kvm/vmx/nested.c:330\n vmx_free_vcpu+0x11f/0x2a0 arch/x86/kvm/vmx/vmx.c:6799\n kvm_arch_vcpu_destroy+0x6b/0x240 arch/x86/kvm/x86.c:10989\n kvm_vcpu_destroy+0x29/0x90 arch/x86/kvm/../../../virt/kvm/kvm_main.c:441\n kvm_free_vcpus arch/x86/kvm/x86.c:11426 [inline]\n kvm_arch_destroy_vm+0x3ef/0x6b0 arch/x86/kvm/x86.c:11545\n kvm_destroy_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:1189 [inline]\n kvm_put_kvm+0x751/0xe40 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1220\n kvm_vcpu_release+0x53/0x60 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3489\n __fput+0x3fc/0x870 fs/file_table.c:280\n task_work_run+0x146/0x1c0 kernel/task_work.c:164\n exit_task_work include/linux/task_work.h:32 [inline]\n do_exit+0x705/0x24f0 kernel/exit.c:832\n do_group_exit+0x168/0x2d0 kernel/exit.c:929\n get_signal+0x1740/0x2120 kernel/signal.c:2852\n arch_do_signal_or_restart+0x9c/0x730 arch/x86/kernel/signal.c:868\n handle_signal_work kernel/entry/common.c:148 [inline]\n exit_to_user_mode_loop kernel/entry/common.c:172 [inline]\n exit_to_user_mode_prepare+0x191/0x220 kernel/entry/common.c:207\n __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]\n syscall_exit_to_user_mode+0x2e/0x70 kernel/entry/common.c:300\n do_syscall_64+0x53/0xd0 arch/x86/entry/common.c:86\n entry_SYSCALL_64_after_hwframe+0x44/0xae"}, {"lang": "es", "value": "En el kernel de Linux, se resolvi\u00f3 la siguiente vulnerabilidad: KVM: VMX: borre siempre vmx-&gt;fail en emulation_required Revierta un cambio relativamente reciente que establece vmx-&gt;fail si la vCPU est\u00e1 en L2 y emulation_required es verdadero, ya que ese comportamiento es completamente falso. Configurar vmx-&gt;fail y sintetizar una VM-Exit es contradictorio y incorrecto: (a) es imposible tener VM-Fail y VM-Exit (b) vmcs.EXIT_REASON no se modifica en VM-Fail (c) emulation_required se refiere al estado invitado y las comprobaciones del estado invitado son siempre salidas de VM, no fallas de VM. Para KVM espec\u00edficamente, emulation_required se maneja antes de las salidas anidadas en __vmx_handle_exit(), por lo que configurar vmx-&gt;fail no tiene un efecto inmediato, es decir, las llamadas de KVM a handle_invalid_guest_state() y vmx-&gt;fail se ignoran. Configurar vmx-&gt;fail puede, en \u00faltima instancia, generar una ADVERTENCIA en nested_vmx_vmexit() al desactivar la VM, ya que KVM nunca espera que vmx-&gt;fail se configure cuando L2 est\u00e1 activo, KVM siempre refleja esos errores en L1. ------------[ cortar aqu\u00ed ]------------ ADVERTENCIA: CPU: 0 PID: 21158 en arch/x86/kvm/vmx/nested.c:4548 nested_vmx_vmexit+0x16bd/0x17e0 arch/x86/kvm/vmx/nested.c:4547 M\u00f3dulos vinculados en: CPU: 0 PID: 21158 Comm: syz-executor.1 No contaminado 5.16.0-rc3-syzkaller #0 Nombre de hardware: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:nested_vmx_vmexit+0x16bd/0x17e0 arch/x86/kvm/vmx/nested.c:4547 C\u00f3digo: &lt;0f&gt; 0b e9 2e f8 ff ff e8 57 b3 5d 00 0f 0b e9 00 f1 ff ff 89 e9 80 Seguimiento de llamadas: vmx_leave_nested arch/x86/kvm/vmx/nested.c:6220 [en l\u00ednea] nested_vmx_free_vcpu+0x83/0xc0 arch/x86/kvm/vmx/nested.c: 330 vmx_free_vcpu+0x11f/0x2a0 arch/x86/kvm/vmx/vmx.c:6799 kvm_arch_vcpu_destroy+0x6b/0x240 arch/x86/kvm/x86.c:10989 kvm_vcpu_destroy+0x29/0x90 arch/x86/kvm/.. /. ./../virt/kvm/kvm_main.c:441 kvm_free_vcpus arch/x86/kvm/x86.c:11426 [en l\u00ednea] kvm_arch_destroy_vm+0x3ef/0x6b0 arch/x86/kvm/x86.c:11545 kvm_destroy_vm arch/x86/ kvm/../../../virt/kvm/kvm_main.c:1189 [en l\u00ednea] kvm_put_kvm+0x751/0xe40 arch/x86/kvm/../../../virt/kvm/kvm_main.c :1220 kvm_vcpu_release+0x53/0x60 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3489 __fput+0x3fc/0x870 fs/file_table.c:280 task_work_run+0x146/0x1c0 kernel/ task_work.c:164 exit_task_work include/linux/task_work.h:32 [en l\u00ednea] do_exit+0x705/0x24f0 kernel/exit.c:832 do_group_exit+0x168/0x2d0 kernel/exit.c:929 get_signal+0x1740/0x2120 kernel/se\u00f1al .c:2852 arch_do_signal_or_restart+0x9c/0x730 arch/x86/kernel/signal.c:868 handle_signal_work kernel/entry/common.c:148 [en l\u00ednea] exit_to_user_mode_loop kernel/entry/common.c:172 [en l\u00ednea] exit_to_user_mode_prepare+0x191/ 0x220 kernel/entry/common.c:207 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [en l\u00ednea] syscall_exit_to_user_mode+0x2e/0x70 kernel/entry/common.c:300 do_syscall_64+0x53/0xd0 arch/x86/entry/common. c:86 entrada_SYSCALL_64_after_hwframe+0x44/0xae"}], "id": "CVE-2021-47092", "lastModified": "2024-03-05T13:41:01.900", "metrics": {}, "published": "2024-03-04T18:15:07.723", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/a80dfc025924024d2c61a4c1b8ef62b2fce76a04"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/e4e4e7cb229821cd215031abc47efdab5486a67c"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Awaiting Analysis"}

{"bugzilla": {"description": "kernel: KVM: VMX: Always clear vmx-&gt;fail on emulation_required", "id": "2267932", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2267932"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.5", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-20", "details": ["In the Linux kernel, the following vulnerability has been resolved:\nKVM: VMX: Always clear vmx->fail on emulation_required\nRevert a relatively recent change that set vmx->fail if the vCPU is in L2\nand emulation_required is true, as that behavior is completely bogus.\nSetting vmx->fail and synthesizing a VM-Exit is contradictory and wrong:\n(a) it's impossible to have both a VM-Fail and VM-Exit\n(b) vmcs.EXIT_REASON is not modified on VM-Fail\n(c) emulation_required refers to guest state and guest state checks are\nalways VM-Exits, not VM-Fails.\nFor KVM specifically, emulation_required is handled before nested exits\nin __vmx_handle_exit(), thus setting vmx->fail has no immediate effect,\ni.e. KVM calls into handle_invalid_guest_state() and vmx->fail is ignored.\nSetting vmx->fail can ultimately result in a WARN in nested_vmx_vmexit()\nfiring when tearing down the VM as KVM never expects vmx->fail to be set\nwhen L2 is active, KVM always reflects those errors into L1.\n------------[ cut here ]------------\nWARNING: CPU: 0 PID: 21158 at arch/x86/kvm/vmx/nested.c:4548\nnested_vmx_vmexit+0x16bd/0x17e0\narch/x86/kvm/vmx/nested.c:4547\nModules linked in:\nCPU: 0 PID: 21158 Comm: syz-executor.1 Not tainted 5.16.0-rc3-syzkaller #0\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011\nRIP: 0010:nested_vmx_vmexit+0x16bd/0x17e0 arch/x86/kvm/vmx/nested.c:4547\nCode: <0f> 0b e9 2e f8 ff ff e8 57 b3 5d 00 0f 0b e9 00 f1 ff ff 89 e9 80\nCall Trace:\nvmx_leave_nested arch/x86/kvm/vmx/nested.c:6220 [inline]\nnested_vmx_free_vcpu+0x83/0xc0 arch/x86/kvm/vmx/nested.c:330\nvmx_free_vcpu+0x11f/0x2a0 arch/x86/kvm/vmx/vmx.c:6799\nkvm_arch_vcpu_destroy+0x6b/0x240 arch/x86/kvm/x86.c:10989\nkvm_vcpu_destroy+0x29/0x90 arch/x86/kvm/../../../virt/kvm/kvm_main.c:441\nkvm_free_vcpus arch/x86/kvm/x86.c:11426 [inline]\nkvm_arch_destroy_vm+0x3ef/0x6b0 arch/x86/kvm/x86.c:11545\nkvm_destroy_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:1189 [inline]\nkvm_put_kvm+0x751/0xe40 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1220\nkvm_vcpu_release+0x53/0x60 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3489\n__fput+0x3fc/0x870 fs/file_table.c:280\ntask_work_run+0x146/0x1c0 kernel/task_work.c:164\nexit_task_work include/linux/task_work.h:32 [inline]\ndo_exit+0x705/0x24f0 kernel/exit.c:832\ndo_group_exit+0x168/0x2d0 kernel/exit.c:929\nget_signal+0x1740/0x2120 kernel/signal.c:2852\narch_do_signal_or_restart+0x9c/0x730 arch/x86/kernel/signal.c:868\nhandle_signal_work kernel/entry/common.c:148 [inline]\nexit_to_user_mode_loop kernel/entry/common.c:172 [inline]\nexit_to_user_mode_prepare+0x191/0x220 kernel/entry/common.c:207\n__syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]\nsyscall_exit_to_user_mode+0x2e/0x70 kernel/entry/common.c:300\ndo_syscall_64+0x53/0xd0 arch/x86/entry/common.c:86\nentry_SYSCALL_64_after_hwframe+0x44/0xae"], "name": "CVE-2021-47092", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2024-03-04T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2021-47092\nhttps://nvd.nist.gov/vuln/detail/CVE-2021-47092\nhttps://lore.kernel.org/linux-cve-announce/2024030414-CVE-2021-47092-36e2@gregkh/T"], "threat_severity": "Moderate", "upstream_fix": "kernel 5.15.12, kernel 5.16"}