INFO: task kworker/u9:5:1089 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u9:5    state:D stack:25952 pid:1089  tgid:1089  ppid:2      task_flags:0x4208060 flags:0x00004000
Workqueue: events_unbound linkwatch_event
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7e6/0x1350
 linkwatch_event+0xe/0x60
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 ret_from_fork_asm+0x1a/0x30
 </TASK>

Showing all locks held in the system:
2 locks held by kworker/0:1/10:
5 locks held by kworker/u8:0/12:
1 lock held by khungtaskd/34:
 #0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
3 locks held by kworker/u10:1/36:
7 locks held by kworker/u11:0/55:
3 locks held by kworker/u9:5/1089:
 #0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90007037bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f53a248 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60
2 locks held by getty/5673:
 #0: ffff888023ff40a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900029062f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
3 locks held by kworker/u11:2/5849:
 #0: ffff88811b291148 ((wq_completion)hci3){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90004247bc0 ((work_completion)(&hdev->power_on)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffff88811bc2cdc0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_power_on+0x1ac/0x680
2 locks held by kworker/u8:2/5861:
3 locks held by kworker/0:3/5899:
 #0: ffff88801a480d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc900045afbc0 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f53a248 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20
3 locks held by kworker/u8:4/5913:
 #0: ffff8881073a6948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc9000463fbc0 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f53a248 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30
3 locks held by kworker/u10:10/6542:
3 locks held by kworker/u10:18/6558:
2 locks held by syz.0.655/9100:
 #0: ffffffff8f52d3b0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffffffff8f53a248 (rtnl_mutex){+.+.}-{4:4}, at: cfg802154_pernet_exit+0x19/0xe0
3 locks held by syz.2.660/9122:
 #0: ffffffff8f52d3b0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffffffff8f53a248 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x2ab/0x800
 #2: ffff8881000e0188 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_add_one+0x2c2/0x520
1 lock held by syz-executor/9142:
 #0: ffffffff8f53a248 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0
1 lock held by syz-executor/9155:
1 lock held by syz-executor/9161:
 #0: ffff8881000e0188 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_dop_revalidate+0x9e/0x5d0
1 lock held by udevd/9162:
 #0: ffff8881000e0188 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_dop_revalidate+0x9e/0x5d0
2 locks held by dhcpcd/9163:
 #0: ffff88811f7de258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xcd0
 #1: ffffffff8e13fb78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730

=============================================

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 34 Comm: khungtaskd 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:
 <TASK>
 dump_stack_lvl+0x189/0x250
 nmi_cpu_backtrace+0x39e/0x3d0
 nmi_trigger_cpumask_backtrace+0x17a/0x300
 watchdog+0xf93/0xfe0
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 ret_from_fork_asm+0x1a/0x30
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 55 Comm: kworker/u11:0 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: hci3 hci_rx_work
RIP: 0010:lock_acquire+0x45/0x360
Code: 89 54 24 04 89 f3 49 89 fd 48 8b ac 24 98 00 00 00 65 48 8b 05 bc 72 03 11 48 89 44 24 58 0f 1f 44 00 00 65 8b 05 bf 72 03 11 <83> f8 08 0f 83 b8 01 00 00 89 c0 48 0f a3 05 a8 31 06 0e 73 16 e8
RSP: 0018:ffffc900001dfb38 EFLAGS: 00000282
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000002
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e13a0e0
RBP: ffffffff8172c195 R08: 0000000000000000 R09: 0000000000000000
R10: ffffc900001dfcf8 R11: ffffffff81ac3b00 R12: 0000000000000002
R13: ffffffff8e13a0e0 R14: 0000000000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8881a3c13000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3a157d6038 CR3: 000000003a7d0000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 unwind_next_frame+0xc2/0x2390
 arch_stack_walk+0x11c/0x150
 stack_trace_save+0x9c/0xe0
 kasan_save_track+0x3e/0x80
 __kasan_slab_alloc+0x6c/0x80
 kmem_cache_alloc_noprof+0x1c1/0x3c0
 skb_clone+0x212/0x3a0
 maybe_deliver+0x98/0x160
 br_flood+0x31a/0x6a0
 br_handle_frame_finish+0x15a3/0x1c50
 br_nf_hook_thresh+0x3c6/0x4a0
 br_nf_pre_routing_finish_ipv6+0x999/0xd60
 br_nf_pre_routing_ipv6+0x37e/0x6b0
 br_handle_frame+0x982/0x14c0
 __netif_receive_skb_core+0x10b9/0x4020
 __netif_receive_skb+0x72/0x380
 process_backlog+0x60e/0x14f0
 __napi_poll+0xc7/0x360
 net_rx_action+0x707/0xe30
 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:console_flush_all+0x7f7/0xc40
Code: 48 21 c3 0f 85 e9 01 00 00 e8 a5 48 1f 00 48 8b 5c 24 20 4d 85 f6 75 07 e8 96 48 1f 00 eb 06 e8 8f 48 1f 00 fb 48 8b 44 24 28 <42> 80 3c 20 00 74 08 48 89 df e8 6a c8 82 00 48 8b 1b 48 8b 44 24
RSP: 0018:ffffc900007df2a0 EFLAGS: 00000293
RAX: 1ffffffff1d369af RBX: ffffffff8e9b4d78 RCX: ffff88801b355640
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900007df3f0 R08: ffffffff8fa38f37 R09: 1ffffffff1f471e6
R10: dffffc0000000000 R11: fffffbfff1f471e7 R12: dffffc0000000000
R13: 0000000000000001 R14: 0000000000000200 R15: ffffffff8e9b4d20
 console_unlock+0xc4/0x270
 vprintk_emit+0x5b7/0x7a0
 _printk+0xcf/0x120
 bt_warn+0x10b/0x160
 hci_cmd_complete_evt+0x478/0x960
 hci_event_packet+0x78f/0x1200
 hci_rx_work+0x46a/0xe80
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 ret_from_fork_asm+0x1a/0x30
 </TASK>
