rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-....: (10499 ticks this GP) idle=0b5/1/0x4000000000000000 softirq=8115/8115 fqs=5223 
	(t=10502 jiffies g=11429 q=1014)
NMI backtrace for cpu 1
CPU: 1 PID: 3985 Comm: syz-executor.4 Not tainted 5.16.0-rc4-next-20211210-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+0x262/0x3f0 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:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202
Code: 0f 1f 44 00 00 55 48 8b 74 24 08 48 89 fd 48 83 c7 18 e8 4e 04 06 f8 48 89 ef e8 96 7a 06 f8 e8 01 62 27 f8 fb bf 01 00 00 00 <e8> 26 33 f9 f7 65 8b 05 af 8d ab 76 85 c0 74 02 5d c3 e8 fb 62 a9
RSP: 0018:ffffc900041c72a8 EFLAGS: 00000202
RAX: 0000000001c3fb9b RBX: dffffc0000000000 RCX: 1ffffffff1ff4d16
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001
RBP: ffff888010c678f0 R08: 0000000000000001 R09: ffffffff8ffa194f
R10: 0000000000000001 R11: 0000000000000001 R12: 1ffffffff1701e30
R13: ffff88802be99d40 R14: ffff888010c678f0 R15: ffffc90002bdf098
 rwsem_down_write_slowpath+0x576/0x1110 kernel/locking/rwsem.c:1118
 __down_write_common kernel/locking/rwsem.c:1259 [inline]
 __down_write_common kernel/locking/rwsem.c:1256 [inline]
 __down_write kernel/locking/rwsem.c:1268 [inline]
 down_write+0x135/0x150 kernel/locking/rwsem.c:1515
 kernfs_activate+0x87/0x240 fs/kernfs/dir.c:1309
 kernfs_add_one+0x3c6/0x550 fs/kernfs/dir.c:767
 __kernfs_create_file+0x29c/0x350 fs/kernfs/file.c:1016
 sysfs_add_file_mode_ns+0x20f/0x3f0 fs/sysfs/file.c:294
 create_files fs/sysfs/group.c:64 [inline]
 internal_create_group+0x322/0xb10 fs/sysfs/group.c:148
 internal_create_groups.part.0+0x90/0x140 fs/sysfs/group.c:188
 internal_create_groups fs/sysfs/group.c:184 [inline]
 sysfs_create_groups+0x25/0x50 fs/sysfs/group.c:214
 device_add_groups drivers/base/core.c:2473 [inline]
 device_add_attrs drivers/base/core.c:2621 [inline]
 device_add+0x81f/0x1ee0 drivers/base/core.c:3345
 netdev_register_kobject+0x181/0x430 net/core/net-sysfs.c:2008
 register_netdevice+0xd31/0x1500 net/core/dev.c:9656
 register_netdev+0x2d/0x50 net/core/dev.c:9780
 ip6_tnl_init_net+0x479/0x890 net/ipv6/ip6_tunnel.c:2288
 ops_init+0xaf/0x470 net/core/net_namespace.c:140
 setup_net+0x40f/0xa30 net/core/net_namespace.c:326
 copy_net_ns+0x318/0x760 net/core/net_namespace.c:470
 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110
 copy_namespaces+0x391/0x450 kernel/nsproxy.c:178
 copy_process+0x2e53/0x7480 kernel/fork.c:2180
 kernel_clone+0xe7/0xab0 kernel/fork.c:2621
 __do_sys_clone+0xc1/0x100 kernel/fork.c:2738
 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: 0033:0x7ffbe1850e99
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:00007ffbe01c6168 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007ffbe1963f60 RCX: 00007ffbe1850e99
RDX: 9999999999999999 RSI: 0000000000000000 RDI: 0c75e43cfae22dd4
RBP: 00007ffbe18aaff1 R08: ffffffffffffffff R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fffbfd88ecf R14: 00007ffbe01c6300 R15: 0000000000022000
 </TASK>
----------------
Code disassembly (best guess):
   0:	0f 1f 44 00 00       	nopl   0x0(%rax,%rax,1)
   5:	55                   	push   %rbp
   6:	48 8b 74 24 08       	mov    0x8(%rsp),%rsi
   b:	48 89 fd             	mov    %rdi,%rbp
   e:	48 83 c7 18          	add    $0x18,%rdi
  12:	e8 4e 04 06 f8       	callq  0xf8060465
  17:	48 89 ef             	mov    %rbp,%rdi
  1a:	e8 96 7a 06 f8       	callq  0xf8067ab5
  1f:	e8 01 62 27 f8       	callq  0xf8276225
  24:	fb                   	sti
  25:	bf 01 00 00 00       	mov    $0x1,%edi
* 2a:	e8 26 33 f9 f7       	callq  0xf7f93355 <-- trapping instruction
  2f:	65 8b 05 af 8d ab 76 	mov    %gs:0x76ab8daf(%rip),%eax        # 0x76ab8de5
  36:	85 c0                	test   %eax,%eax
  38:	74 02                	je     0x3c
  3a:	5d                   	pop    %rbp
  3b:	c3                   	retq
  3c:	e8                   	.byte 0xe8
  3d:	fb                   	sti
  3e:	62                   	.byte 0x62
  3f:	a9                   	.byte 0xa9