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: 1 PID: 9098 at arch/x86/kvm/vmx/vmx.c:4678 handle_desc+0x8e/0xa0 arch/x86/kvm/vmx/vmx.c:4678
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 9098 Comm: syz-executor647 Not tainted 5.3.0-rc8+ #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+0x1d8/0x2f8 lib/dump_stack.c:113
 panic+0x25c/0x799 kernel/panic.c:219
 __warn+0x22f/0x230 kernel/panic.c:576
 report_bug+0x190/0x290 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:179 [inline]
 do_error_trap+0xd7/0x440 arch/x86/kernel/traps.c:272
 do_invalid_op+0x36/0x40 arch/x86/kernel/traps.c:291
 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1028
RIP: 0010:handle_desc+0x8e/0xa0 arch/x86/kvm/vmx/vmx.c:4678
Code: 31 ff 89 c6 e8 f3 cc 56 00 31 c0 85 db 0f 94 c0 5b 41 5e 41 5f 5d c3 e8 40 c9 56 00 48 c7 c7 aa b3 34 88 31 c0 e8 a5 0f 40 00 <0f> 0b eb c6 0f 1f 40 00 66 2e 0f 1f 84 00 00 00 00 00 55 48 89 e5
RSP: 0018:ffff888099f0fb00 EFLAGS: 00010246
RAX: 0000000000000024 RBX: 0000000000000000 RCX: 870d88d6828e7a00
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: ffff888099f0fb18 R08: ffffffff815cfa74 R09: ffffed1015d66088
R10: ffffed1015d66088 R11: 0000000000000000 R12: dffffc0000000000
R13: ffff888091118040 R14: ffff888091118040 R15: 0000000000000000
 vmx_handle_exit+0x3c8/0xd50 arch/x86/kvm/vmx/vmx.c:5886
 vcpu_enter_guest+0x3f8d/0x54b0 arch/x86/kvm/x86.c:8095
 vcpu_run+0x393/0xd40 arch/x86/kvm/x86.c:8159
 kvm_arch_vcpu_ioctl_run+0x636/0x900 arch/x86/kvm/x86.c:8367
 kvm_vcpu_ioctl+0x6cf/0xaf0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2765
 do_vfs_ioctl+0x744/0x1730 fs/ioctl.c:46
 ksys_ioctl fs/ioctl.c:713 [inline]
 __do_sys_ioctl fs/ioctl.c:720 [inline]
 __se_sys_ioctl fs/ioctl.c:718 [inline]
 __x64_sys_ioctl+0xe3/0x120 fs/ioctl.c:718
 do_syscall_64+0xfe/0x140 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x443819
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:00007fff494c1a98 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fff494c1aa0 RCX: 0000000000443819
RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000006
RBP: 0000000000000000 R08: 00000000004010a0 R09: 00000000004010a0
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004048c0
R13: 0000000000404950 R14: 0000000000000000 R15: 0000000000000000
Kernel Offset: disabled
Rebooting in 86400 seconds..