INFO: task kworker/0:5:18635 blocked for more than 140 seconds.
      Not tainted 4.9.128+ #40
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/0:5     D29432 18635      2 0x00000000
Workqueue: events linkwatch_event
 ffff88018ff58000 ffff880182484200 ffff880182484200 ffff880185db8000
 ffff8801db621018 ffff88019e9d7ae8 ffffffff8277eeb2 0000000000000002
 ffff88018ff588b0 ffffed0031feb115 00ff88018ff58000 ffff8801db6218f0
Call Trace:
 [<ffffffff827803df>] schedule+0x7f/0x1b0 kernel/sched/core.c:3553
 [<ffffffff82780d63>] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3586
 [<ffffffff827829e6>] __mutex_lock_common kernel/locking/mutex.c:582 [inline]
 [<ffffffff827829e6>] mutex_lock_nested+0x326/0x870 kernel/locking/mutex.c:621
 [<ffffffff822c3077>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
 [<ffffffff822d99ee>] linkwatch_event+0xe/0x60 net/core/link_watch.c:236
 [<ffffffff8112cb71>] process_one_work+0x791/0x1470 kernel/workqueue.c:2092
 [<ffffffff8112d926>] worker_thread+0xd6/0x10a0 kernel/workqueue.c:2226
 [<ffffffff8113e00d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff8278e15c>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373

Showing all locks held in the system:
2 locks held by khungtaskd/24:
 #0:  (rcu_read_lock){......}, at: [<ffffffff8130a0ac>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff8130a0ac>] watchdog+0x11c/0xa20 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff813e71ec>] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336
2 locks held by getty/2018:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff8278c082>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff81cdee72>] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142
3 locks held by kworker/1:3/13141:
 #0:  ("%s"("ipv6_addrconf")){.+.+..}, at: [<ffffffff8112ca80>] process_one_work+0x6a0/0x1470 kernel/workqueue.c:2085
 #1:  ((addr_chk_work).work){+.+...}, at: [<ffffffff8112cab8>] process_one_work+0x6d8/0x1470 kernel/workqueue.c:2089
 #2:  (rtnl_mutex){+.+.+.}, at: [<ffffffff822c3077>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
3 locks held by kworker/0:5/18635:
 #0:  ("events"){.+.+.+}, at: [<ffffffff8112ca80>] process_one_work+0x6a0/0x1470 kernel/workqueue.c:2085
 #1:  ((linkwatch_work).work){+.+...}, at: [<ffffffff8112cab8>] process_one_work+0x6d8/0x1470 kernel/workqueue.c:2089
 #2:  (rtnl_mutex){+.+.+.}, at: [<ffffffff822c3077>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70

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

NMI backtrace for cpu 0
CPU: 0 PID: 24 Comm: khungtaskd Not tainted 4.9.128+ #40
 ffff8801d9907d08 ffffffff81af2469 0000000000000000 0000000000000000
 0000000000000000 0000000000000001 ffffffff810967d0 ffff8801d9907d40
 ffffffff81afd1c9 0000000000000000 0000000000000000 0000000000000003
Call Trace:
 [<ffffffff81af2469>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81af2469>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81afd1c9>] nmi_cpu_backtrace.cold.0+0x48/0x87 lib/nmi_backtrace.c:99
 [<ffffffff81afd15c>] nmi_trigger_cpumask_backtrace+0x12c/0x151 lib/nmi_backtrace.c:60
 [<ffffffff810968d4>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff8130a63d>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff8130a63d>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff8130a63d>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff8130a63d>] watchdog+0x6ad/0xa20 kernel/hung_task.c:239
 [<ffffffff8113e00d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff8278e15c>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 16492 Comm: syz-executor1 Not tainted 4.9.128+ #40
task: ffff880185db8000 task.stack: ffff88019e798000
RIP: 0033:[<000000000040157b>] 
c [<000000000040157b>] 0x40157b
RSP: 002b:00007f27ecf7b690  EFLAGS: 00000282
RAX: 00000000c1274104 RBX: 000000000000000b RCX: 0000000000457679
RDX: 0000000000000000 RSI: 00007f27ecf7b6c0 RDI: 000000000000000b
RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004d7950 R14: 00000000004c48c6 R15: 0000000000000000
FS:  00007f27ecf7c700(0000) GS:ffff8801db700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000cd13e0 CR3: 00000001c888d000 CR4: 00000000001606b0
DR0: 0000000020000000 DR1: 0000000020000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600