{ "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": "2024-08-04T05:24:39.809Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2024-05-29T05:01:56.996Z" }, "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": "custom" }, { "version": "5.15.12", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "custom" }, { "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-a5840b7849dd" } }, "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" ] } ] } ] } }