============================================
WARNING: possible recursive locking detected
6.16.0-rc5-syzkaller-00159-g47c84997c686 #0 Not tainted
--------------------------------------------
syz.2.804/9298 is trying to acquire lock:
ffff888029d5b558 (&qdisc_xmit_lock_key#3){+.-.}-{3:3}, at: sch_direct_xmit+0x153/0x4b0

but task is already holding lock:
ffff88810d820958 (&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

18 locks held by syz.2.804/9298:
 #0: ffffffff8f510c10 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffffffff8f2752f0 (devices_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x19a/0x270
 #2: ffffffff8f2754b0 (rdma_nets_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x1d2/0x270
 #3: ffff88812d994f60 (&device->compat_devs_mutex){+.+.}-{4:4}, at: add_one_compat_dev+0xee/0x5c0
 #4: ffff88801b2f7988 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_add_one+0x41/0x520
 #5: ffffffff8e13f160 (rcu_read_lock){....}-{1:3}, at: kernfs_root+0x1c/0x230
 #6: ffffc900001e0be0 ((&ndev->rs_timer)){+.-.}-{0:0}, at: call_timer_fn+0xbe/0x5f0
 #7: ffffffff8e13f160 (rcu_read_lock){....}-{1:3}, at: ndisc_send_skb+0x208/0x1400
 #8: ffffffff8e13f160 (rcu_read_lock){....}-{1:3}, at: ip6_finish_output2+0x701/0x16a0
 #9: ffffffff8e13f1c0 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x27e/0x3a70
 #10: ffffffff8e13f160 (rcu_read_lock){....}-{1:3}, at: bond_start_xmit+0x101/0x1a90
 #11: ffffffff8e13f1c0 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x27e/0x3a70
 #12: ffff888120f4f258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#2){+...}-{3:3}, at: __dev_queue_xmit+0x1300/0x3a70
 #13: ffff88810d820958 (&qdisc_xmit_lock_key#3){+.-.}-{3:3}, at: sch_direct_xmit+0x153/0x4b0
 #14: ffffffff8e13f160 (rcu_read_lock){....}-{1:3}, at: ip_finish_output2+0x452/0x1160
 #15: ffffffff8e13f160 (rcu_read_lock){....}-{1:3}, at: arp_xmit+0x23/0x270
 #16: ffffffff8e13f1c0 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x27e/0x3a70
 #17: ffff888106270258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#2){+...}-{3:3}, at: __dev_queue_xmit+0x1300/0x3a70

stack backtrace:
CPU: 1 UID: 0 PID: 9298 Comm: syz.2.804 Not tainted 6.16.0-rc5-syzkaller-00159-g47c84997c686 #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+0x17b6/0x3a70
 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
 iptunnel_xmit+0x571/0xa00
 ip_tunnel_xmit+0x1c3c/0x2380
 gre_tap_xmit+0x590/0x7a0
 dev_hard_start_xmit+0x2d7/0x830
 sch_direct_xmit+0x241/0x4b0
 __dev_queue_xmit+0x17b6/0x3a70
 bond_dev_queue_xmit+0x10b/0x1e0
 bond_start_xmit+0xc0a/0x1a90
 dev_hard_start_xmit+0x2d7/0x830
 __dev_queue_xmit+0x1adf/0x3a70
 ip6_finish_output2+0x11bc/0x16a0
 ip6_finish_output+0x234/0x7d0
 ndisc_send_skb+0xb47/0x1400
 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:rcu_is_watching+0x55/0xb0
Code: ec bb 8d 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 2c 89 7c 00 48 c7 c3 58 7f a1 92 49 03 1e 48 89 d8 48 c1 e8 03 <42> 0f b6 04 38 84 c0 75 34 8b 03 65 ff 0d 19 20 f9 10 74 11 83 e0
RSP: 0018:ffffc90002a27498 EFLAGS: 00000a06
RAX: 1ffff11026cc65eb RBX: ffff888136632f58 RCX: 0d3734491c77d400
RDX: ffff888023295640 RSI: ffffffff8be29da0 RDI: ffffffff8be29d60
RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff825d58bc
R10: dffffc0000000000 R11: ffffed100365ef25 R12: dffffc0000000000
R13: ffff88812ce0da88 R14: ffffffff8dbbec78 R15: dffffc0000000000
 rcu_read_lock_held+0x15/0x50
 kernfs_root+0xf6/0x230
 kernfs_link_sibling+0xe6/0x3e0
 kernfs_add_one+0x1e0/0x520
 __kernfs_create_file+0x22b/0x2e0
 sysfs_add_file_mode_ns+0x238/0x300
 internal_create_group+0x66d/0x1110
 sysfs_create_groups+0x59/0x120
 ib_setup_port_attrs+0xd96/0x2070
 add_one_compat_dev+0x3d6/0x5c0
 rdma_dev_init_net+0x1dd/0x270
 ops_init+0x35c/0x5c0
 setup_net+0x219/0x4b0
 copy_net_ns+0x31b/0x4d0
 create_new_namespaces+0x3f3/0x720
 unshare_nsproxy_namespaces+0x11c/0x170
 ksys_unshare+0x4c8/0x8c0
 __x64_sys_unshare+0x38/0x50
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0bb3d8e929
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:00007f0bb4b5e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f0bb3fb5fa0 RCX: 00007f0bb3d8e929
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000064000600
RBP: 00007f0bb3e10b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f0bb3fb5fa0 R15: 00007ffcc051cda8
 </TASK>
