rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-....: (1 GPs behind) idle=36f/1/0x4000000000000000 softirq=26121/26123 fqs=5113 
	(t=10500 jiffies g=48621 q=2187)
NMI backtrace for cpu 0
CPU: 0 PID: 15656 Comm: vhost-15655 Not tainted 5.15.0-rc5-next-20211015-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:__sanitizer_cov_trace_cmp8+0x69/0x70 kernel/kcov.c:268
Code: 3c cd 28 00 00 00 48 39 fe 72 1f 48 83 c2 01 4c 89 44 38 e8 48 c7 44 38 e0 06 00 00 00 48 89 4c 38 f0 4e 89 54 c8 20 48 89 10 <c3> 66 0f 1f 44 00 00 53 41 89 fb 41 89 f1 bf 03 00 00 00 65 48 8b
RSP: 0018:ffffc900047e7ae8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffff888018865700 RDI: 0000000000000003
RBP: 0000000000000000 R08: 000000000000000f R09: ffffc900047e7b1f
R10: ffffffff86dc5174 R11: 0000000000000000 R12: ffff88807e9ab680
R13: 000000000000000f R14: ffffffffffffffff R15: 0000000000000000
 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:	3c cd                	cmp    $0xcd,%al
   2:	28 00                	sub    %al,(%rax)
   4:	00 00                	add    %al,(%rax)
   6:	48 39 fe             	cmp    %rdi,%rsi
   9:	72 1f                	jb     0x2a
   b:	48 83 c2 01          	add    $0x1,%rdx
   f:	4c 89 44 38 e8       	mov    %r8,-0x18(%rax,%rdi,1)
  14:	48 c7 44 38 e0 06 00 	movq   $0x6,-0x20(%rax,%rdi,1)
  1b:	00 00
  1d:	48 89 4c 38 f0       	mov    %rcx,-0x10(%rax,%rdi,1)
  22:	4e 89 54 c8 20       	mov    %r10,0x20(%rax,%r9,8)
  27:	48 89 10             	mov    %rdx,(%rax)
* 2a:	c3                   	retq <-- trapping instruction
  2b:	66 0f 1f 44 00 00    	nopw   0x0(%rax,%rax,1)
  31:	53                   	push   %rbx
  32:	41 89 fb             	mov    %edi,%r11d
  35:	41 89 f1             	mov    %esi,%r9d
  38:	bf 03 00 00 00       	mov    $0x3,%edi
  3d:	65                   	gs
  3e:	48                   	rex.W
  3f:	8b                   	.byte 0x8b