============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
syz.2.494/7776 is trying to acquire lock:
ffff88810f1ff558 (&qdisc_xmit_lock_key#3){+.-.}-{3:3}, at: sch_direct_xmit+0x153/0x4b0

but task is already holding lock:
ffff88801fcf2558 (&qdisc_xmit_lock_key#3){+.-.}-{3:3}, at: sch_direct_xmit+0x153/0x4b0

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&qdisc_xmit_lock_key#3);
  lock(&qdisc_xmit_lock_key#3);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

14 locks held by syz.2.494/7776:
 #0: ffffffff8f538bc8 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0
 #1: ffffc900001e0be0 ((&ndev->rs_timer)){+.-.}-{0:0}, at: call_timer_fn+0xbe/0x5f0
 #2: ffffffff8e139ee0 (rcu_read_lock){....}-{1:3}, at: ndisc_send_skb+0x1e4/0x1510
 #3: ffffffff8e139ee0 (rcu_read_lock){....}-{1:3}, at: ip6_output+0x126/0x550
 #4: ffffffff8e139f40 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x27b/0x3b50
 #5: ffffffff8e139ee0 (rcu_read_lock){....}-{1:3}, at: bond_start_xmit+0xf8/0x1a10
 #6: ffffffff8e139f40 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x27b/0x3b50
 #7: ffff88802f014258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#3){+...}-{3:3}, at: __dev_queue_xmit+0x138a/0x3b50
 #8: ffff88801fcf2558 (&qdisc_xmit_lock_key#3){+.-.}-{3:3}, at: sch_direct_xmit+0x153/0x4b0
 #9: ffffffff8e139ee0 (rcu_read_lock){....}-{1:3}, at: ip_output+0x5b/0x450
 #10: ffffffff8e139ee0 (rcu_read_lock){....}-{1:3}, at: ip_finish_output2+0x452/0x1160
 #11: ffffffff8e139ee0 (rcu_read_lock){....}-{1:3}, at: arp_xmit+0x23/0x270
 #12: ffffffff8e139f40 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x27b/0x3b50
 #13: ffff88802f527258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#3){+...}-{3:3}, at: __dev_queue_xmit+0x138a/0x3b50

stack backtrace:
CPU: 1 UID: 0 PID: 7776 Comm: syz.2.494 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <IRQ>
 dump_stack_lvl+0x189/0x250
 print_deadlock_bug+0x28b/0x2a0
 validate_chain+0x1a3f/0x2140
 __lock_acquire+0xab9/0xd20
 lock_acquire+0x120/0x360
 _raw_spin_lock+0x2e/0x40
 sch_direct_xmit+0x153/0x4b0
 __dev_queue_xmit+0x1857/0x3b50
 NF_HOOK+0x310/0x3a0
 arp_xmit+0x16c/0x270
 arp_solicit+0xc1d/0xe60
 __neigh_event_send+0xf70/0x1560
 neigh_resolve_output+0x198/0x750
 ip_finish_output2+0xd40/0x1160
 ip_output+0x29f/0x450
 iptunnel_xmit+0x5f8/0xa90
 ip_tunnel_xmit+0x1c41/0x2390
 gre_tap_xmit+0x590/0x7a0
 dev_hard_start_xmit+0x2d7/0x830
 sch_direct_xmit+0x241/0x4b0
 __dev_queue_xmit+0x1857/0x3b50
 bond_start_xmit+0xdc7/0x1a10
 dev_hard_start_xmit+0x2d7/0x830
 __dev_queue_xmit+0x1b8d/0x3b50
 ip6_finish_output2+0xf70/0x1480
 ip6_output+0x340/0x550
 ndisc_send_skb+0xbce/0x1510
 addrconf_rs_timer+0x369/0x670
 call_timer_fn+0x17e/0x5f0
 __run_timer_base+0x61a/0x860
 run_timer_softirq+0xb7/0x180
 handle_softirqs+0x286/0x870
 __irq_exit_rcu+0xca/0x1f0
 irq_exit_rcu+0x9/0x30
 sysvec_apic_timer_interrupt+0xa6/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:lockdep_unregister_key+0x2c5/0x310
Code: 65 48 8b 05 0d 20 03 11 48 3b 44 24 10 0f 84 26 fe ff ff e8 cd b6 dc 09 e8 f8 b7 dc 09 41 f7 c7 00 02 00 00 74 bd fb 40 84 ed <75> bc eb cd 90 0f 0b 90 e9 19 ff ff ff 90 0f 0b 90 e9 2a ff ff ff
RSP: 0018:ffffc90002a17998 EFLAGS: 00000246
RAX: e3192e850db12d00 RBX: ffff8880338a4298 RCX: e3192e850db12d00
RDX: ffffffff93646338 RSI: ffffffff8d9ccc72 RDI: ffffffff8be33800
RBP: ffff8880338a4200 R08: 0000000000000000 R09: ffffffff81aa8268
R10: dffffc0000000000 R11: fffffbfff1f47147 R12: 0000000000000000
R13: 0000000000001000 R14: 0000000000000001 R15: 0000000000000203
 __qdisc_destroy+0x166/0x420
 dev_shutdown+0x93/0x440
 unregister_netdevice_many_notify+0xe0f/0x1ff0
 unregister_netdevice_queue+0x33c/0x380
 __tun_detach+0xda4/0x1560
 tun_chr_close+0x10a/0x1c0
 __fput+0x44c/0xa70
 task_work_run+0x1d4/0x260
 exit_to_user_mode_loop+0xec/0x110
 do_syscall_64+0x2bd/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f273938ebe9
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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe40a366b8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 0000000000016afd RCX: 00007f273938ebe9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f27395c7da0 R08: 0000000000000001 R09: 0000001a40a369af
R10: 0000001b30e20000 R11: 0000000000000246 R12: 00007f27395c5fac
R13: 00007f27395c5fa0 R14: ffffffffffffffff R15: 00007ffe40a367d0
 </TASK>
