rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-....: (10499 ticks this GP) idle=5c5/1/0x4000000000000000 softirq=185561/185561 fqs=4753 
	(t=10500 jiffies g=360041 q=556)
NMI backtrace for cpu 1
CPU: 1 PID: 10914 Comm: syz-executor.0 Not tainted 5.16.0-rc2-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:111
 nmi_trigger_cpumask_backtrace+0x1b3/0x230 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:627 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:711 [inline]
 rcu_pending kernel/rcu/tree.c:3878 [inline]
 rcu_sched_clock_irq.cold+0x9d/0x746 kernel/rcu/tree.c:2597
 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:1421
 __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+0x40/0xc0 arch/x86/kernel/apic/apic.c:1097
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:check_kcov_mode+0x31/0x40 kernel/kcov.c:178
Code: 89 c2 81 e2 00 01 00 00 a9 00 01 ff 00 74 10 31 c0 85 d2 74 15 8b 96 a4 15 00 00 85 d2 74 0b 8b 86 80 15 00 00 39 f8 0f 94 c0 <c3> 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 31 c0 65 8b 15 07 db
RSP: 0018:ffffc90000dc0c40 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff88802ef83100 RCX: fffffff0a3da8872
RDX: 0000000000000000 RSI: ffff88801ca53a00 RDI: 0000000000000003
RBP: fffffff0a3da8872 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff875d5986 R11: 0000000000000000 R12: fffffff0a3da8872
R13: ffff88807bdc3300 R14: 0000000000000000 R15: 0000000000000000
 write_comp_data kernel/kcov.c:221 [inline]
 __sanitizer_cov_trace_cmp8+0x1d/0x70 kernel/kcov.c:267
 pie_calculate_probability+0x336/0x7c0 net/sched/sch_pie.c:390
 fq_pie_timer+0x170/0x2a0 net/sched/sch_fq_pie.c:383
 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421
 expire_timers kernel/time/timer.c:1466 [inline]
 __run_timers.part.0+0x675/0xa20 kernel/time/timer.c:1734
 __run_timers kernel/time/timer.c:1715 [inline]
 run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1747
 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558
 invoke_softirq kernel/softirq.c:432 [inline]
 __irq_exit_rcu+0x123/0x180 kernel/softirq.c:636
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:648
 sysvec_apic_timer_interrupt+0x93/0xc0 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:lock_acquire+0x1ef/0x510 kernel/locking/lockdep.c:5605
Code: c4 a5 7e 83 f8 01 0f 85 b4 02 00 00 9c 58 f6 c4 02 0f 85 9f 02 00 00 48 83 7c 24 08 00 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c3 48 c7 03 00 00 00 00 48 c7 43 08 00 00 00 00 48 8b 84 24
RSP: 0018:ffffc9000c207b48 EFLAGS: 00000206
RAX: dffffc0000000000 RBX: 1ffff92001840f6b RCX: ffffffff815c62af
RDX: 1ffff1100394a88b RSI: 0000000000000002 RDI: 0000000000000000
RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff8ff72a0f
R10: fffffbfff1fee541 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: ffff88806eb53c90 R15: 0000000000000000
 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
 _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154
 spin_lock include/linux/spinlock.h:349 [inline]
 d_set_mounted+0x16b/0x290 fs/dcache.c:1490
 get_mountpoint+0x15c/0x400 fs/namespace.c:756
 attach_recursive_mnt+0x151/0x1060 fs/namespace.c:2164
 graft_tree+0x187/0x210 fs/namespace.c:2287
 do_loopback fs/namespace.c:2402 [inline]
 path_mount+0x1ab5/0x1fa0 fs/namespace.c:3312
 do_mount fs/namespace.c:3331 [inline]
 __do_sys_mount fs/namespace.c:3539 [inline]
 __se_sys_mount fs/namespace.c:3516 [inline]
 __x64_sys_mount+0x27f/0x300 fs/namespace.c:3516
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f701d49bae9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f701aa11188 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f701d5aef60 RCX: 00007f701d49bae9
RDX: 0000000000000000 RSI: 00000000200004c0 RDI: 0000000020000000
RBP: 00007f701d4f5f6d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000007a04 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f701dae2b2f R14: 00007f701aa11300 R15: 0000000000022000
 </TASK>
----------------
Code disassembly (best guess):
   0:	89 c2                	mov    %eax,%edx
   2:	81 e2 00 01 00 00    	and    $0x100,%edx
   8:	a9 00 01 ff 00       	test   $0xff0100,%eax
   d:	74 10                	je     0x1f
   f:	31 c0                	xor    %eax,%eax
  11:	85 d2                	test   %edx,%edx
  13:	74 15                	je     0x2a
  15:	8b 96 a4 15 00 00    	mov    0x15a4(%rsi),%edx
  1b:	85 d2                	test   %edx,%edx
  1d:	74 0b                	je     0x2a
  1f:	8b 86 80 15 00 00    	mov    0x1580(%rsi),%eax
  25:	39 f8                	cmp    %edi,%eax
  27:	0f 94 c0             	sete   %al
* 2a:	c3                   	retq <-- trapping instruction
  2b:	66 66 2e 0f 1f 84 00 	data16 nopw %cs:0x0(%rax,%rax,1)
  32:	00 00 00 00
  36:	0f 1f 00             	nopl   (%rax)
  39:	31 c0                	xor    %eax,%eax
  3b:	65                   	gs
  3c:	8b                   	.byte 0x8b
  3d:	15                   	.byte 0x15
  3e:	07                   	(bad)
  3f:	db                   	.byte 0xdb