INFO: task kworker/1:0:18 blocked for more than 140 seconds.
      Not tainted 4.9.125+ #37
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/1:0     D26824    18      2 0x00000000
Workqueue: ipv6_addrconf addrconf_verify_work
 ffff8801da6f4740 0000000000000000 ffff8801d16b4200 ffff8801da6b2f80
 ffff8801db721018 ffff8801da717ae8 ffffffff8277d092 0000000000000002
 ffff8801da6f4ff0 ffffed003b4de9fd 00ff8801da6f4740 ffff8801db7218f0
Call Trace:
 [<ffffffff8277e5bf>] schedule+0x7f/0x1b0 kernel/sched/core.c:3553
 [<ffffffff8277ef43>] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3586
 [<ffffffff82780bc6>] __mutex_lock_common kernel/locking/mutex.c:582 [inline]
 [<ffffffff82780bc6>] mutex_lock_nested+0x326/0x870 kernel/locking/mutex.c:621
 [<ffffffff822c12d7>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
 [<ffffffff82639a1e>] addrconf_verify_work+0xe/0x20 net/ipv6/addrconf.c:4366
 [<ffffffff8112c511>] process_one_work+0x791/0x1470 kernel/workqueue.c:2092
 [<ffffffff8112d2c6>] worker_thread+0xd6/0x10a0 kernel/workqueue.c:2226
 [<ffffffff8113d9ad>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff8278c35c>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373

Showing all locks held in the system:
3 locks held by kworker/1:0/18:
 #0:  ("%s"("ipv6_addrconf")){.+.+..}, at: [<ffffffff8112c420>] process_one_work+0x6a0/0x1470 kernel/workqueue.c:2085
 #1:  ((addr_chk_work).work){+.+...}, at: [<ffffffff8112c458>] process_one_work+0x6d8/0x1470 kernel/workqueue.c:2089
 #2:  (rtnl_mutex){+.+.+.}, at: [<ffffffff822c12d7>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
2 locks held by khungtaskd/24:
 #0:  (rcu_read_lock){......}, at: [<ffffffff81309abc>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff81309abc>] watchdog+0x11c/0xa20 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff813e68fc>] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336
1 lock held by rsyslogd/1894:
 #0:  (&f->f_pos_lock){+.+.+.}, at: [<ffffffff8154c11c>] __fdget_pos+0xac/0xd0 fs/file.c:781
2 locks held by getty/2022:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff8278a262>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+.+.}, at: [<ffffffff81cdd442>] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142
4 locks held by kworker/u4:24/10592:
 #0:  ("%s""netns"){.+.+.+}, at: [<ffffffff8112c420>] process_one_work+0x6a0/0x1470 kernel/workqueue.c:2085
 #1:  (net_cleanup_work){+.+.+.}, at: [<ffffffff8112c458>] process_one_work+0x6d8/0x1470 kernel/workqueue.c:2089
 #2:  (net_mutex){+.+.+.}, at: [<ffffffff82268d9f>] cleanup_net+0x13f/0x630 net/core/net_namespace.c:439
 #3:  (rtnl_mutex){+.+.+.}, at: [<ffffffff822c12d7>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor0/16543:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff822c12d7>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor2/16594:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff822c12d7>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor2/16598:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff822c12d7>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor6/16609:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff822c12d7>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor6/16632:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff822c12d7>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor6/16634:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff822c12d7>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor4/16613:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff822c12d7>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor4/16616:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff822c12d7>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor1/16623:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff822c12d7>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor1/16626:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff822c12d7>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor3/16629:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff822ca6fb>] rtnl_lock net/core/rtnetlink.c:70 [inline]
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff822ca6fb>] rtnetlink_rcv+0x1b/0x40 net/core/rtnetlink.c:4067
1 lock held by syz-executor3/16637:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff822c12d7>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor3/16642:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff822ca6fb>] rtnl_lock net/core/rtnetlink.c:70 [inline]
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff822ca6fb>] rtnetlink_rcv+0x1b/0x40 net/core/rtnetlink.c:4067
1 lock held by syz-executor3/16643:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff822c12d7>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70

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

NMI backtrace for cpu 0
CPU: 0 PID: 24 Comm: khungtaskd Not tainted 4.9.125+ #37
 ffff8801d9907d08 ffffffff81af0ae9 0000000000000000 0000000000000000
 0000000000000000 0000000000000001 ffffffff810967d0 ffff8801d9907d40
 ffffffff81afb849 0000000000000000 0000000000000000 0000000000000003
Call Trace:
 [<ffffffff81af0ae9>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81af0ae9>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81afb849>] nmi_cpu_backtrace.cold.0+0x48/0x87 lib/nmi_backtrace.c:99
 [<ffffffff81afb7dc>] 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
 [<ffffffff8130a04d>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff8130a04d>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff8130a04d>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff8130a04d>] watchdog+0x6ad/0xa20 kernel/hung_task.c:239
 [<ffffffff8113d9ad>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff8278c35c>] 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 skipped: idling at pc 0xffffffff8278ada6