rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-....: (1 GPs behind) idle=6b3/1/0x4000000000000000 softirq=89525/89526 fqs=4997 
	(t=10500 jiffies g=165069 q=6473)
NMI backtrace for cpu 0
CPU: 0 PID: 2899 Comm: vhost-2895 Not tainted 5.15.0-rc7-next-20211028-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:3922 [inline]
 rcu_sched_clock_irq.cold+0x9d/0x746 kernel/rcu/tree.c:2620
 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+0x37/0x60 kernel/kcov.c:200
Code: 81 e1 00 01 00 00 65 48 8b 14 25 40 70 02 00 a9 00 01 ff 00 74 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
RSP: 0018:ffffc90005a77b20 EFLAGS: 00000246
RAX: 0000000000000002 RBX: 0000000000000010 RCX: 0000000000000000
RDX: ffff888021a99d40 RSI: ffffffff86a6f01c RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000010 R09: ffffc90005a77b1f
R10: ffffffff86a6f00b R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000003 R15: 0000000000000000
 iotlb_access_ok+0x1bc/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:	81 e1 00 01 00 00    	and    $0x100,%ecx
   6:	65 48 8b 14 25 40 70 	mov    %gs:0x27040,%rdx
   d:	02 00
   f:	a9 00 01 ff 00       	test   $0xff0100,%eax
  14:	74 0e                	je     0x24
  16:	85 c9                	test   %ecx,%ecx
  18:	74 35                	je     0x4f
  1a:	8b 82 ac 15 00 00    	mov    0x15ac(%rdx),%eax
  20:	85 c0                	test   %eax,%eax
  22:	74 2b                	je     0x4f
  24:	8b 82 88 15 00 00    	mov    0x1588(%rdx),%eax
* 2a:	83 f8 02             	cmp    $0x2,%eax <-- trapping instruction
  2d:	75 20                	jne    0x4f
  2f:	48 8b 8a 90 15 00 00 	mov    0x1590(%rdx),%rcx
  36:	8b 92 8c 15 00 00    	mov    0x158c(%rdx),%edx
  3c:	48 8b 01             	mov    (%rcx),%rax
  3f:	48                   	rex.W