IPVS: stopping backup sync thread 6634 ...
IPVS: sync thread started: state = BACKUP, mcast_ifn = sit0, syncid = 0, id = 0
INFO: task kworker/1:2:1823 blocked for more than 120 seconds.
      Not tainted 4.9.90-gdd1e37e #6
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/1:2     D27648  1823      2 0x00000000
Workqueue: events_power_efficient reg_check_chans_work
 ffff8801cea6b000 0000000000000000 ffff8801b6188fc0 ffff8801d9b73000
 ffff8801db321b98 ffff8801ceab7a08 ffffffff838a75cb 0000000000000002
 0000000000000007 00ff8801cea6b000 ffff8801db322468 ffff8801db322490
Call Trace:
 [<ffffffff838a8b6f>] schedule+0x7f/0x1b0 kernel/sched/core.c:3551
 [<ffffffff838a94f3>] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3584
 [<ffffffff838ae292>] __mutex_lock_common kernel/locking/mutex.c:582 [inline]
 [<ffffffff838ae292>] mutex_lock_nested+0x312/0x870 kernel/locking/mutex.c:621
 [<ffffffff82f79737>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
 [<ffffffff835ae2c4>] reg_check_chans_work+0x74/0xde0 net/wireless/reg.c:1652
 [<ffffffff8118b030>] process_one_work+0x7e0/0x1610 kernel/workqueue.c:2092
 [<ffffffff8118bf40>] worker_thread+0xe0/0x10d0 kernel/workqueue.c:2226
 [<ffffffff8119bf4d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff838b865c>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373

Showing all locks held in the system:
3 locks held by kworker/1:1/25:
 #0:  ("%s"("ipv6_addrconf")){.+.+..}, at: [<ffffffff8118af42>] work_static include/linux/workqueue.h:186 [inline]
 #0:  ("%s"("ipv6_addrconf")){.+.+..}, at: [<ffffffff8118af42>] set_work_data kernel/workqueue.c:617 [inline]
 #0:  ("%s"("ipv6_addrconf")){.+.+..}, at: [<ffffffff8118af42>] set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
 #0:  ("%s"("ipv6_addrconf")){.+.+..}, at: [<ffffffff8118af42>] process_one_work+0x6f2/0x1610 kernel/workqueue.c:2085
 #1:  ((addr_chk_work).work){+.+...}, at: [<ffffffff8118af7c>] process_one_work+0x72c/0x1610 kernel/workqueue.c:2089
 #2:  (rtnl_mutex){+.+.+.}, at: [<ffffffff82f79737>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
2 locks held by khungtaskd/514:
 #0:  (rcu_read_lock){......}, at: [<ffffffff81372185>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff81372185>] watchdog+0x125/0xa70 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff81236c50>] debug_show_all_locks+0x70/0x280 kernel/locking/lockdep.c:4336
3 locks held by kworker/1:2/1823:
 #0:  ("events_power_efficient"){.+.+.+}, at: [<ffffffff8118af42>] work_static include/linux/workqueue.h:186 [inline]
 #0:  ("events_power_efficient"){.+.+.+}, at: [<ffffffff8118af42>] set_work_data kernel/workqueue.c:617 [inline]
 #0:  ("events_power_efficient"){.+.+.+}, at: [<ffffffff8118af42>] set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
 #0:  ("events_power_efficient"){.+.+.+}, at: [<ffffffff8118af42>] process_one_work+0x6f2/0x1610 kernel/workqueue.c:2085
 #1:  ((reg_check_chans).work){+.+...}, at: [<ffffffff8118af7c>] process_one_work+0x72c/0x1610 kernel/workqueue.c:2089
 #2:  (rtnl_mutex){+.+.+.}, at: [<ffffffff82f79737>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by rsyslogd/3653:
 #0:  (&f->f_pos_lock){+.+.+.}, at: [<ffffffff815d2f5f>] __fdget_pos+0x9f/0xc0 fs/file.c:781
2 locks held by getty/3782:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff838b66a2>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff8200a6a4>] n_tty_read+0x1f4/0x16c0 drivers/tty/n_tty.c:2133
1 lock held by syz-executor2/6628:
 #0:  (ipvs->sync_mutex){+.+.+.}, at: [<ffffffff831ad9c0>] do_ip_vs_set_ctl+0x240/0xc00 net/netfilter/ipvs/ip_vs_ctl.c:2402
2 locks held by syz-executor2/6636:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff82f79737>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
 #1:  (ipvs->sync_mutex){+.+.+.}, at: [<ffffffff831ae067>] do_ip_vs_set_ctl+0x8e7/0xc00 net/netfilter/ipvs/ip_vs_ctl.c:2397
1 lock held by ipvs-b:9:0/6634:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff82f79737>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor1/6642:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff82f7e24b>] rtnl_lock net/core/rtnetlink.c:70 [inline]
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff82f7e24b>] rtnetlink_rcv+0x1b/0x40 net/core/rtnetlink.c:4064

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

NMI backtrace for cpu 1
CPU: 1 PID: 514 Comm: khungtaskd Not tainted 4.9.90-gdd1e37e #6
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d86cfd00 ffffffff81d94ee9 0000000000000000 0000000000000001
 0000000000000001 0000000000000001 ffffffff810bb920 ffff8801d86cfd38
 ffffffff81da000d 0000000000000001 0000000000000000 ffff8801cea6b418
Call Trace:
 [<ffffffff81d94ee9>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d94ee9>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81da000d>] nmi_cpu_backtrace+0xfd/0x120 lib/nmi_backtrace.c:99
 [<ffffffff81da0147>] nmi_trigger_cpumask_backtrace+0x117/0x190 lib/nmi_backtrace.c:60
 [<ffffffff810bba14>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff81372750>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff81372750>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff81372750>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff81372750>] watchdog+0x6f0/0xa70 kernel/hung_task.c:239
 [<ffffffff8119bf4d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff838b865c>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at pc 0xffffffff838b7116