L1TF CPU bug present and SMT on, data leak possible. See CVE-2018-3646 and https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/l1tf.html for details.
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WARNING: CPU: 0 PID: 6869 at arch/x86/kvm/vmx/vmx.c:4809 handle_exception_nmi+0x10e1/0x12d0 arch/x86/kvm/vmx/vmx.c:4809
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 6869 Comm: syz-executor982 Not tainted 5.9.0-rc6-syzkaller #0
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+0x198/0x1fd lib/dump_stack.c:118
 panic+0x382/0x7fb kernel/panic.c:231
 __warn.cold+0x20/0x4b kernel/panic.c:600
 report_bug+0x1bd/0x210 lib/bug.c:198
 handle_bug+0x38/0x90 arch/x86/kernel/traps.c:234
 exc_invalid_op+0x14/0x40 arch/x86/kernel/traps.c:254
 asm_exc_invalid_op+0x12/0x20 arch/x86/include/asm/idtentry.h:536
RIP: 0010:handle_exception_nmi+0x10e1/0x12d0 arch/x86/kvm/vmx/vmx.c:4809
Code: 0f 84 16 f3 ff ff e8 ee 5c 5a 00 48 89 ef c7 85 ac 0e 00 00 00 00 00 00 e8 5c 87 f0 ff 41 89 c4 e9 fd f2 ff ff e8 cf 5c 5a 00 <0f> 0b e9 85 f8 ff ff e8 c3 5c 5a 00 be f5 ff ff ff bf 01 00 00 00
RSP: 0018:ffffc90000f27a78 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff811bd9f5
RDX: ffff888095896180 RSI: ffffffff811be171 RDI: 0000000000000001
RBP: ffff88808e984040 R08: 0000000000000001 R09: ffff88808e984387
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 00000000000000b9 R14: ffff88808e984380 R15: 0000000000000000
 vmx_handle_exit+0x2a6/0x1510 arch/x86/kvm/vmx/vmx.c:6123
 vcpu_enter_guest+0x18f4/0x3c20 arch/x86/kvm/x86.c:8655
 vcpu_run arch/x86/kvm/x86.c:8720 [inline]
 kvm_arch_vcpu_ioctl_run+0x440/0x1780 arch/x86/kvm/x86.c:8937
 kvm_vcpu_ioctl+0x467/0xdf0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3230
 kvm_vcpu_compat_ioctl+0x1a2/0x340 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3426
 __do_compat_sys_ioctl+0x1d3/0x230 fs/ioctl.c:842
 do_syscall_32_irqs_on arch/x86/entry/common.c:78 [inline]
 __do_fast_syscall_32+0x60/0x90 arch/x86/entry/common.c:137
 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:160
 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c
RIP: 0023:0xf7fcb549
Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 002b:00000000ff9e4fcc EFLAGS: 00000286 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 000000000000ae80
RDX: 0000000000000000 RSI: 00000000080eb088 RDI: 00000000ff9e5020
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
Kernel Offset: disabled
Rebooting in 86400 seconds..