============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
kworker/0:0/9 is trying to acquire lock:
ffff888115c37558 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: sch_direct_xmit+0x15f/0x4c0

but task is already holding lock:
ffff8881bcd05558 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: __dev_queue_xmit+0x11be/0x3230

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

       CPU0
       ----
  lock(&qdisc_xmit_lock_key#4);
  lock(&qdisc_xmit_lock_key#4);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

12 locks held by kworker/0:0/9:
 #0: ffff888172382548 ((wq_completion)mld){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0
 #1: ffffc900000e7b80 ((work_completion)(&(&idev->mc_ifc_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0
 #2: ffff8881af123538 (&idev->mc_lock){+.+.}-{4:4}, at: mld_ifc_work+0x2d/0xd60
 #3: ffffffff8e341aa0 (rcu_read_lock){....}-{1:3}, at: mld_sendpack+0x213/0xe40
 #4: ffffffff8e341aa0 (rcu_read_lock){....}-{1:3}, at: ip6_output+0x126/0x550
 #5: ffffffff8e341b00 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x2aa/0x3230
 #6: ffff8881bcd05558 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: __dev_queue_xmit+0x11be/0x3230
 #7: ffffffff8e341aa0 (rcu_read_lock){....}-{1:3}, at: ip_output+0x5b/0x450
 #8: ffffffff8e341aa0 (rcu_read_lock){....}-{1:3}, at: ip_finish_output2+0x44d/0x1180
 #9: ffffffff8e341aa0 (rcu_read_lock){....}-{1:3}, at: arp_xmit+0x23/0x270
 #10: ffffffff8e341b00 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x2aa/0x3230
 #11: ffff88810daa1228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#3){+...}-{3:3}, at: __dev_queue_xmit+0xf1a/0x3230

stack backtrace:
CPU: 0 UID: 0 PID: 9 Comm: kworker/0:0 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
Workqueue: mld mld_ifc_work
Call Trace:
 <TASK>
 dump_stack_lvl+0x1a9/0x280
 print_deadlock_bug+0x279/0x290
 __lock_acquire+0x253f/0x2cf0
 lock_acquire+0x116/0x340
 _raw_spin_lock+0x2e/0x40
 sch_direct_xmit+0x15f/0x4c0
 __dev_queue_xmit+0x13b1/0x3230
 NF_HOOK+0x33a/0x3c0
 arp_xmit+0x16c/0x270
 arp_solicit+0xc6d/0xee0
 __neigh_event_send+0xf05/0x14a0
 neigh_resolve_output+0x198/0x750
 ip_finish_output2+0xd5d/0x1180
 ip_output+0x29f/0x450
 iptunnel_xmit+0x59f/0xa00
 ip_tunnel_xmit+0x1cea/0x2430
 ipgre_xmit+0x8e6/0xc60
 dev_hard_start_xmit+0x2cd/0x7f0
 __dev_queue_xmit+0x14da/0x3230
 ip6_finish_output2+0x11c1/0x1540
 ip6_output+0x340/0x550
 NF_HOOK+0xa2/0x3a0
 mld_sendpack+0x8b4/0xe40
 mld_ifc_work+0x83e/0xd60
 process_scheduled_works+0xaec/0x17a0
 worker_thread+0x89f/0xd90
 kthread+0x726/0x8b0
 ret_from_fork+0x5b0/0xb20
 ret_from_fork_asm+0x1a/0x30
 </TASK>
