rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-....: (10499 ticks this GP) idle=639/1/0x4000000000000000 softirq=43772/43772 fqs=5158 
	(t=10500 jiffies g=75789 q=3207)
NMI backtrace for cpu 0
CPU: 0 PID: 20687 Comm: vhost-20686 Not tainted 5.15.0-rc5-next-20211013-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_pc+0x4c/0x60 kernel/kcov.c:205
Code: 0e 85 c9 74 35 8b 82 ac 15 00 00 85 c0 74 2b 8b 82 88 15 00 00 83 f8 02 75 20 48 8b 8a 90 15 00 00 8b 92 8c 15 00 00 48 8b 01 <48> 83 c0 01 48 39 c2 76 07 48 89 34 c1 48 89 01 c3 0f 1f 00 41 55
RSP: 0018:ffffc90004f5fb20 EFLAGS: 00000246
RAX: 000000000003ffff RBX: ffff888071392a80 RCX: ffffc9000fdd8000
RDX: 0000000000040000 RSI: ffffffff86db080f RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffc90004f5fb1f
R10: ffffffff86dbfe3d R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000003 R15: 0000000000000000
 iotlb_access_ok+0x1df/0x3e0 drivers/vhost/vhost.c:1337
 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), 1 bytes skipped:
   0:	85 c9                	test   %ecx,%ecx
   2:	74 35                	je     0x39
   4:	8b 82 ac 15 00 00    	mov    0x15ac(%rdx),%eax
   a:	85 c0                	test   %eax,%eax
   c:	74 2b                	je     0x39
   e:	8b 82 88 15 00 00    	mov    0x1588(%rdx),%eax
  14:	83 f8 02             	cmp    $0x2,%eax
  17:	75 20                	jne    0x39
  19:	48 8b 8a 90 15 00 00 	mov    0x1590(%rdx),%rcx
  20:	8b 92 8c 15 00 00    	mov    0x158c(%rdx),%edx
  26:	48 8b 01             	mov    (%rcx),%rax
* 29:	48 83 c0 01          	add    $0x1,%rax <-- trapping instruction
  2d:	48 39 c2             	cmp    %rax,%rdx
  30:	76 07                	jbe    0x39
  32:	48 89 34 c1          	mov    %rsi,(%rcx,%rax,8)
  36:	48 89 01             	mov    %rax,(%rcx)
  39:	c3                   	retq
  3a:	0f 1f 00             	nopl   (%rax)
  3d:	41 55                	push   %r13