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.
hrtimer: interrupt took 36927 ns
debugfs: Directory 'vcpu0' with parent '7200-5' already present!
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (10499 ticks this GP) idle=e4e/1/0x4000000000000002 softirq=9271/9280 fqs=6 
	(t=10500 jiffies g=5473 q=554)
rcu: rcu_preempt kthread starved for 10487 jiffies! g5473 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
rcu: RCU grace-period kthread stack dump:
rcu_preempt     R  running task    29104    10      2 0x80004000
Call Trace:
 context_switch kernel/sched/core.c:3380 [inline]
 __schedule+0x895/0x1960 kernel/sched/core.c:4080
 schedule+0xc3/0x2b0 kernel/sched/core.c:4154
 schedule_timeout+0x38b/0xad0 kernel/time/timer.c:1895
 rcu_gp_fqs_loop kernel/rcu/tree.c:1658 [inline]
 rcu_gp_kthread+0x9f2/0x1890 kernel/rcu/tree.c:1818
 kthread+0x334/0x3f0 kernel/kthread.c:255
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
NMI backtrace for cpu 1
CPU: 1 PID: 7312 Comm: syz-executor5 Not tainted 5.6.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x12d/0x187 lib/dump_stack.c:118
 nmi_cpu_backtrace.cold.7+0x4b/0x84 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x18b/0x1b7 lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_dump_cpu_stacks+0x16f/0x1bc kernel/rcu/tree_stall.h:254
 print_cpu_stall kernel/rcu/tree_stall.h:475 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:549 [inline]
 rcu_pending kernel/rcu/tree.c:3030 [inline]
 rcu_sched_clock_irq.cold.86+0x514/0xc8b kernel/rcu/tree.c:2276
 update_process_times+0x23/0x50 kernel/time/timer.c:1726
 tick_sched_handle+0x77/0x140 kernel/time/tick-sched.c:171
 tick_sched_timer+0x43/0x100 kernel/time/tick-sched.c:1314
 __run_hrtimer kernel/time/hrtimer.c:1517 [inline]
 __hrtimer_run_queues+0x332/0xb50 kernel/time/hrtimer.c:1579
 hrtimer_interrupt+0x2df/0x760 kernel/time/hrtimer.c:1641
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1119 [inline]
 smp_apic_timer_interrupt+0x16f/0x600 arch/x86/kernel/apic/apic.c:1144
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829
 </IRQ>
RIP: 0010:vcpu_enter_guest arch/x86/kvm/x86.c:8416 [inline]
RIP: 0010:vcpu_run arch/x86/kvm/x86.c:8513 [inline]
RIP: 0010:kvm_arch_vcpu_ioctl_run+0x2c88/0x5f30 arch/x86/kvm/x86.c:8735
Code: 89 61 00 4c 89 e8 48 c1 e8 03 42 80 3c 20 00 0f 85 a8 28 00 00 48 83 3d a5 76 46 07 00 0f 84 1b 1c 00 00 fb 66 0f 1f 44 00 00 <49> 8d bf 68 01 00 00 48 89 f8 48 c1 e8 03 42 80 3c 20 00 0f 85 50
RSP: 0018:ffff8881d11e7ae0 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13
RAX: 1ffffffff10a7752 RBX: ffffffff882af220 RCX: 0000000000000006
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff8881bd89cad4
RBP: ffff8881d11e7cb0 R08: 0000000000000006 R09: fffffbfff13ba7ab
R10: fffffbfff13ba7aa R11: ffffffff89dd3d57 R12: dffffc0000000000
R13: ffffffff8853ba90 R14: ffff8881d2f000b8 R15: ffff8881d2f00080
 kvm_vcpu_ioctl+0x507/0xac0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2932
 vfs_ioctl fs/ioctl.c:47 [inline]
 ksys_ioctl+0xc4/0x120 fs/ioctl.c:763
 __do_sys_ioctl fs/ioctl.c:772 [inline]
 __se_sys_ioctl fs/ioctl.c:770 [inline]
 __x64_sys_ioctl+0x6e/0xb0 fs/ioctl.c:770
 do_syscall_64+0xd0/0x630 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4571e9
Code: fd b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 cb b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f72c803fc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f72c80406d4 RCX: 00000000004571e9
RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000006
RBP: 00000000009300a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004cf7d0 R14: 00000000004c5a59 R15: 0000000000000000