============================================
WARNING: possible recursive locking detected
6.16.0-syzkaller-06600-g1dbf1d590d10 #0 Not tainted
--------------------------------------------
swapper/1/0 is trying to acquire lock:
ffff88802b341a18 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#3){+.-.}-{3:3}, at: __dev_queue_xmit+0x22b7/0x3b50

but task is already holding lock:
ffff88802a0b9258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#3){+.-.}-{3:3}, at: __dev_queue_xmit+0x138a/0x3b50

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

       CPU0
       ----
  lock(dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#3);
  lock(dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#3);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

8 locks held by swapper/1/0:
 #0: ffffc900001e0be0 ((&ndev->rs_timer)){+.-.}-{0:0}, at: call_timer_fn+0xbe/0x5f0
 #1: ffffffff8e13c4e0 (rcu_read_lock){....}-{1:3}, at: ndisc_send_skb+0x20c/0x1440
 #2: ffffffff8e13c4e0 (rcu_read_lock){....}-{1:3}, at: ip6_finish_output2+0x701/0x16a0
 #3: ffffffff8e13c540 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x27b/0x3b50
 #4: ffff88802a0b9258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#3){+.-.}-{3:3}, at: __dev_queue_xmit+0x138a/0x3b50
 #5: ffffffff8e13c4e0 (rcu_read_lock){....}-{1:3}, at: ip_output+0x60/0x3c0
 #6: ffffffff8e13c4e0 (rcu_read_lock){....}-{1:3}, at: ip_finish_output2+0x452/0x1160
 #7: ffffffff8e13c540 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x27b/0x3b50

stack backtrace:
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted 6.16.0-syzkaller-06600-g1dbf1d590d10 #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
 __dev_queue_xmit+0x22b7/0x3b50
 ip_finish_output2+0xd40/0x1160
 ip_output+0x2a1/0x3c0
 iptunnel_xmit+0x592/0xa40
 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
 ip6_finish_output2+0x11bc/0x16a0
 ndisc_send_skb+0xb54/0x1440
 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:pv_native_safe_halt+0x13/0x20
Code: 53 e8 02 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d 13 6f 18 00 f3 0f 1e fa fb f4 <c3> cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000177de0 EFLAGS: 00000282
RAX: 9324b2b5be590600 RBX: ffffffff81969b18 RCX: 9324b2b5be590600
RDX: 0000000000000001 RSI: ffffffff8d9792e3 RDI: ffffffff8be30a00
RBP: ffffc90000177f20 R08: ffff888136632f5b R09: 1ffff11026cc65eb
R10: dffffc0000000000 R11: ffffed1026cc65ec R12: ffffffff8fa07bf0
R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff1102001e000
 default_idle+0x13/0x20
 default_idle_call+0x74/0xb0
 do_idle+0x1e8/0x510
 cpu_startup_entry+0x44/0x60
 start_secondary+0x101/0x110
 common_startup_64+0x13e/0x147
 </TASK>
