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: 8759 at arch/x86/kvm/vmx/vmx.c:4689 handle_desc+0x78/0x90 arch/x86/kvm/vmx/vmx.c:4689
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 8759 Comm: syz-executor825 Not tainted 5.3.0-next-20190919 #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+0x172/0x1f0 lib/dump_stack.c:113
 panic+0x2dc/0x755 kernel/panic.c:220
 __warn.cold+0x2f/0x3c kernel/panic.c:581
 report_bug+0x289/0x300 lib/bug.c:195
 fixup_bug arch/x86/kernel/traps.c:179 [inline]
 fixup_bug arch/x86/kernel/traps.c:174 [inline]
 do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:272
 do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:291
 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1028
RIP: 0010:handle_desc+0x78/0x90 arch/x86/kvm/vmx/vmx.c:4689
Code: 59 00 31 f6 4c 89 e7 e8 16 c9 f4 ff 31 ff 41 89 c4 89 c6 e8 3a 70 59 00 31 c0 45 85 e4 5b 0f 94 c0 41 5c 5d c3 e8 a8 6e 59 00 <0f> 0b eb cf e8 8f df 94 00 eb ab 0f 1f 00 66 2e 0f 1f 84 00 00 00
RSP: 0018:ffff888099af79a0 EFLAGS: 00010293
RAX: ffff88809312c040 RBX: 0000000000000000 RCX: ffffffff811966e6
RDX: 0000000000000000 RSI: ffffffff81196718 RDI: 0000000000000007
RBP: ffff888099af79b0 R08: ffff88809312c040 R09: ffffed1015d26aed
R10: ffffed1015d26aec R11: ffff8880ae935763 R12: ffff888099ca8040
R13: 000000000000002f R14: ffffffff811966a0 R15: ffff888099ca8040
 vmx_handle_exit+0x29d/0x1720 arch/x86/kvm/vmx/vmx.c:5870
 vcpu_enter_guest+0x10d3/0x6110 arch/x86/kvm/x86.c:8159
 vcpu_run arch/x86/kvm/x86.c:8223 [inline]
 kvm_arch_vcpu_ioctl_run+0x424/0x1760 arch/x86/kvm/x86.c:8431
 kvm_vcpu_ioctl+0x4dc/0xfc0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2764
 vfs_ioctl fs/ioctl.c:47 [inline]
 file_ioctl fs/ioctl.c:539 [inline]
 do_vfs_ioctl+0xdb6/0x13e0 fs/ioctl.c:726
 ksys_ioctl+0xab/0xd0 fs/ioctl.c:743
 __do_sys_ioctl fs/ioctl.c:750 [inline]
 __se_sys_ioctl fs/ioctl.c:748 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:748
 do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290
 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:00007ffeb41f3ee8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007ffeb41f3ef0 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..