L1TF CPU bug present and SMT on, data leak possible. See CVE-2018-3646 and https://www.kernel.org/doc/html/latest/admin-guide/l1tf.html for details. ================================================================== BUG: KMSAN: uninit-value in __vmcs_writel arch/x86/kvm/vmx.c:2399 [inline] BUG: KMSAN: uninit-value in vmcs_write32 arch/x86/kvm/vmx.c:2420 [inline] BUG: KMSAN: uninit-value in vmx_queue_exception+0x757/0x920 arch/x86/kvm/vmx.c:3352 CPU: 0 PID: 6638 Comm: syz-executor166 Not tainted 4.20.0-rc3+ #89 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x32d/0x480 lib/dump_stack.c:113 kmsan_report+0x19f/0x300 mm/kmsan/kmsan.c:911 __msan_warning+0x76/0xc0 mm/kmsan/kmsan_instr.c:415 __vmcs_writel arch/x86/kvm/vmx.c:2399 [inline] vmcs_write32 arch/x86/kvm/vmx.c:2420 [inline] vmx_queue_exception+0x757/0x920 arch/x86/kvm/vmx.c:3352 inject_pending_event arch/x86/kvm/x86.c:7146 [inline] vcpu_enter_guest arch/x86/kvm/x86.c:7641 [inline] vcpu_run arch/x86/kvm/x86.c:7872 [inline] kvm_arch_vcpu_ioctl_run+0x7d81/0x12040 arch/x86/kvm/x86.c:8072 kvm_vcpu_ioctl+0xfb1/0x1f90 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2596 do_vfs_ioctl+0xfbc/0x2f70 fs/ioctl.c:46 ksys_ioctl fs/ioctl.c:713 [inline] __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl+0x1da/0x270 fs/ioctl.c:718 __x64_sys_ioctl+0x4a/0x70 fs/ioctl.c:718 do_syscall_64+0xcf/0x110 arch/x86/entry/common.c:291 entry_SYSCALL_64_after_hwframe+0x63/0xe7 RIP: 0033:0x442a39 Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 1b 0c fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ffef8ea1048 EFLAGS: 00000217 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000442a39 RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005 RBP: 00000000006cd018 R08: 00000000004002c8 R09: 00000000004002c8 R10: 0000000020014000 R11: 0000000000000217 R12: 0000000000403ae0 R13: 0000000000403b70 R14: 0000000000000000 R15: 0000000000000000 Uninit was stored to memory at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:252 [inline] kmsan_save_stack mm/kmsan/kmsan.c:267 [inline] kmsan_internal_chain_origin+0x136/0x240 mm/kmsan/kmsan.c:569 __msan_chain_origin+0x6d/0xb0 mm/kmsan/kmsan_instr.c:292 kvm_multiple_exception arch/x86/kvm/x86.c:483 [inline] kvm_queue_exception_e_p arch/x86/kvm/x86.c:554 [inline] kvm_inject_page_fault+0xa60/0xef0 arch/x86/kvm/x86.c:578 nested_vmx_get_vmptr+0x36f/0x3d0 arch/x86/kvm/vmx.c:8264 handle_vmon+0x5ea/0xe70 arch/x86/kvm/vmx.c:8387 vmx_handle_exit+0x21bd/0xb980 arch/x86/kvm/vmx.c:10600 vcpu_enter_guest arch/x86/kvm/x86.c:7809 [inline] vcpu_run arch/x86/kvm/x86.c:7872 [inline] kvm_arch_vcpu_ioctl_run+0xaeee/0x12040 arch/x86/kvm/x86.c:8072 kvm_vcpu_ioctl+0xfb1/0x1f90 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2596 do_vfs_ioctl+0xfbc/0x2f70 fs/ioctl.c:46 ksys_ioctl fs/ioctl.c:713 [inline] __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl+0x1da/0x270 fs/ioctl.c:718 __x64_sys_ioctl+0x4a/0x70 fs/ioctl.c:718 do_syscall_64+0xcf/0x110 arch/x86/entry/common.c:291 entry_SYSCALL_64_after_hwframe+0x63/0xe7 Local variable description: ----e@nested_vmx_get_vmptr Variable was created at: nested_vmx_get_vmptr+0xa5/0x3d0 arch/x86/kvm/vmx.c:8255 handle_vmon+0x5ea/0xe70 arch/x86/kvm/vmx.c:8387 ==================================================================