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Home CVE Database CVE-2022-48763

CVE-2022-48763

Description

In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Forcibly leave nested virt when SMM state is toggled Forcibly leave nested virtualization operation if userspace toggles SMM state via KVM_SET_VCPU_EVENTS or KVM_SYNC_X86_EVENTS. If userspace forces the vCPU out of SMM while it\'s post-VMXON and then injects an SMI, vmx_enter_smm() will overwrite vmx->nested.smm.vmxon and end up with both vmxon=false and smm.vmxon=false, but all other nVMX state allocated. Don\'t attempt to gracefully handle the transition as (a) most transitions are nonsencial, e.g. forcing SMM while L2 is running, (b) there isn\'t sufficient information to handle all transitions, e.g. SVM wants access to the SMRAM save state, and (c) KVM_SET_VCPU_EVENTS must precede KVM_SET_NESTED_STATE during state restore as the latter disallows putting the vCPU into L2 if SMM is active, and disallows tagging the vCPU as being post-VMXON in SMM if SMM is not active. Abuse of KVM_SET_VCPU_EVENTS manifests as a WARN and memory leak in nVMX due to failure to free vmcs01\'s shadow VMCS, but the bug goes far beyond just a memory leak, e.g. toggling SMM on while L2 is active puts the vCPU in an architecturally impossible state. WARNING: CPU: 0 PID: 3606 at free_loaded_vmcs arch/x86/kvm/vmx/vmx.c:2665 [inline] WARNING: CPU: 0 PID: 3606 at free_loaded_vmcs+0x158/0x1a0 arch/x86/kvm/vmx/vmx.c:2656 Modules linked in: CPU: 1 PID: 3606 Comm: syz-executor725 Not tainted 5.17.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:free_loaded_vmcs arch/x86/kvm/vmx/vmx.c:2665 [inline] RIP: 0010:free_loaded_vmcs+0x158/0x1a0 arch/x86/kvm/vmx/vmx.c:2656 Code: <0f> 0b eb b3 e8 8f 4d 9f 00 e9 f7 fe ff ff 48 89 df e8 92 4d 9f 00 Call Trace: <TASK> kvm_arch_vcpu_destroy+0x72/0x2f0 arch/x86/kvm/x86.c:11123 kvm_vcpu_destroy arch/x86/kvm/../../../virt/kvm/kvm_main.c:441 [inline] kvm_destroy_vcpus+0x11f/0x290 arch/x86/kvm/../../../virt/kvm/kvm_main.c:460 kvm_free_vcpus arch/x86/kvm/x86.c:11564 [inline] kvm_arch_destroy_vm+0x2e8/0x470 arch/x86/kvm/x86.c:11676 kvm_destroy_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:1217 [inline] kvm_put_kvm+0x4fa/0xb00 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1250 kvm_vm_release+0x3f/0x50 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1273 __fput+0x286/0x9f0 fs/file_table.c:311 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 exit_task_work include/linux/task_work.h:32 [inline] do_exit+0xb29/0x2a30 kernel/exit.c:806 do_group_exit+0xd2/0x2f0 kernel/exit.c:935 get_signal+0x4b0/0x28c0 kernel/signal.c:2862 arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:868 handle_signal_work kernel/entry/common.c:148 [inline] exit_to_user_mode_loop kernel/entry/common.c:172 [inline] exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:207 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae </TASK>

Priority: --
CVSS v3: --
Component: linux
Publish Date: Jun 20, 2024
Related ID: --
CVSS v2: --
Modified Date: Jun 20, 2024

Find out more about CVE-2022-48763 from the MITRE-CVE dictionary and NIST NVD


Products Affected

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Product Name Status Defect Fixed Downloads
Linux
Wind River Linux LTS 17 Requires LTSS -- -- --
Wind River Linux 8 Requires LTSS -- -- --
Wind River Linux 9 Requires LTSS -- -- --
Wind River Linux 7 Requires LTSS -- -- --
Wind River Linux LTS 21 Investigate -- -- --
Wind River Linux LTS 22 Fixed LIN1022-9469
10.22.33.17 --
Wind River Linux LTS 18 Requires LTSS -- -- --
Wind River Linux LTS 19 Investigate -- -- --
Wind River Linux CD release N/A -- -- --
Wind River Linux 6 Requires LTSS -- -- --
Wind River Linux LTS 23 Not Vulnerable -- -- --
VxWorks
VxWorks 7 Not Vulnerable -- -- --
VxWorks 6.9 Not Vulnerable -- -- --
Helix Virtualization Platform Cert Edition
Helix Virtualization Platform Cert Edition Not Vulnerable -- -- --
eLxr
eLxr 12 Not Vulnerable -- -- --

Related Products

Product Name Status Defect Fixed Downloads

Notes
Requires LTSS - customers must have active LTSS (Long Term Security Shield) Support to receive up-to-date information about vulnerabilities that may affect legacy software. Please contact your Wind River account team or see https://docs.windriver.com/bundle/Support_and_Maintenance_Supplemental_Terms_and_Conditions and https://support2.windriver.com/index.php?page=plc for more information.
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