rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-....: (1 GPs behind) idle=937/1/0x4000000000000000 softirq=199136/199137 fqs=5141 
	(t=10500 jiffies g=359765 q=1410)
NMI backtrace for cpu 1
CPU: 1 PID: 7110 Comm: vhost-7108 Not tainted 5.15.0-rc3-next-20210930-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:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:105
 nmi_trigger_cpumask_backtrace+0x1ae/0x220 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_dump_cpu_stacks+0x25e/0x3f0 kernel/rcu/tree_stall.h:343
 print_cpu_stall kernel/rcu/tree_stall.h:604 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:688 [inline]
 rcu_pending kernel/rcu/tree.c:3889 [inline]
 rcu_sched_clock_irq.cold+0x9d/0x746 kernel/rcu/tree.c:2608
 update_process_times+0x16d/0x200 kernel/time/timer.c:1785
 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226
 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1428
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline]
 __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103
 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline]
RIP: 0010:check_kcov_mode+0x0/0x40 kernel/kcov.c:166
Code: 48 89 df e8 d2 63 46 00 e9 59 fe ff ff 48 8b 7c 24 08 e8 c3 63 46 00 e9 61 fd ff ff cc cc cc cc cc cc cc cc cc cc cc cc cc cc <65> 8b 05 d9 34 8c 7e 89 c2 81 e2 00 01 00 00 a9 00 01 ff 00 74 10
RSP: 0018:ffffc9000a97fae0 EFLAGS: 00000246
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 1ffff1100fcbf875 RSI: ffff88807904d700 RDI: 0000000000000003
RBP: 0000000000000000 R08: 000000000000000f R09: ffffc9000a97fb1f
R10: ffffffff86c446f4 R11: 0000000000000000 R12: ffff88807e5fc380
R13: 000000000000000f R14: ffffffffffffffff R15: 0000000000000000
 write_comp_data kernel/kcov.c:221 [inline]
 __sanitizer_cov_trace_cmp8+0x1d/0x70 kernel/kcov.c:267
 vhost_iotlb_itree_iter_first drivers/vhost/iotlb.c:19 [inline]
 vhost_iotlb_itree_first+0xd4/0x280 drivers/vhost/iotlb.c:169
 iotlb_access_ok+0x1ce/0x3e0 drivers/vhost/vhost.c:1336
 vq_meta_prefetch+0xbc/0x280 drivers/vhost/vhost.c:1366
 handle_rx+0x145/0x1b40 drivers/vhost/net.c:1140
 vhost_worker+0x23d/0x3d0 drivers/vhost/vhost.c:372
 kthread+0x405/0x4f0 kernel/kthread.c:327
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
----------------
Code disassembly (best guess):
   0:	48 89 df             	mov    %rbx,%rdi
   3:	e8 d2 63 46 00       	callq  0x4663da
   8:	e9 59 fe ff ff       	jmpq   0xfffffe66
   d:	48 8b 7c 24 08       	mov    0x8(%rsp),%rdi
  12:	e8 c3 63 46 00       	callq  0x4663da
  17:	e9 61 fd ff ff       	jmpq   0xfffffd7d
  1c:	cc                   	int3
  1d:	cc                   	int3
  1e:	cc                   	int3
  1f:	cc                   	int3
  20:	cc                   	int3
  21:	cc                   	int3
  22:	cc                   	int3
  23:	cc                   	int3
  24:	cc                   	int3
  25:	cc                   	int3
  26:	cc                   	int3
  27:	cc                   	int3
  28:	cc                   	int3
  29:	cc                   	int3
* 2a:	65 8b 05 d9 34 8c 7e 	mov    %gs:0x7e8c34d9(%rip),%eax        # 0x7e8c350a <-- trapping instruction
  31:	89 c2                	mov    %eax,%edx
  33:	81 e2 00 01 00 00    	and    $0x100,%edx
  39:	a9 00 01 ff 00       	test   $0xff0100,%eax
  3e:	74 10                	je     0x50