INFO: task kworker/1:2:1248 blocked for more than 120 seconds.
      Not tainted 4.13.0-rc5+ #17
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/1:2     D22096  1248      2 0x00000000
Workqueue: events_power_efficient reg_check_chans_work
Call Trace:
 context_switch kernel/sched/core.c:2771 [inline]
 __schedule+0x8e8/0x2070 kernel/sched/core.c:3332
 schedule+0x108/0x440 kernel/sched/core.c:3391
 schedule_preempt_disabled+0x10/0x20 kernel/sched/core.c:3449
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0xadf/0x1870 kernel/locking/mutex.c:893
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
 rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72
 reg_check_chans_work+0xaa/0xfe0 net/wireless/reg.c:1639
 process_one_work+0xbf3/0x1bc0 kernel/workqueue.c:2097
 worker_thread+0x223/0x1860 kernel/workqueue.c:2231
 kthread+0x35e/0x430 kernel/kthread.c:231
 ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:425

Showing all locks held in the system:
2 locks held by khungtaskd/636:
 #0:  (rcu_read_lock){......}, at: [<ffffffff816eee95>] check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff816eee95>] watchdog+0x1c5/0xd60 kernel/hung_task.c:249
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff81550c82>] debug_show_all_locks+0xd2/0x410 kernel/locking/lockdep.c:4417
3 locks held by kworker/1:2/1248:
 #0:  ("events_power_efficient"){.+.+.+}, at: [<ffffffff81474dbf>] __write_once_size include/linux/compiler.h:279 [inline]
 #0:  ("events_power_efficient"){.+.+.+}, at: [<ffffffff81474dbf>] atomic64_set arch/x86/include/asm/atomic64_64.h:33 [inline]
 #0:  ("events_power_efficient"){.+.+.+}, at: [<ffffffff81474dbf>] atomic_long_set include/asm-generic/atomic-long.h:56 [inline]
 #0:  ("events_power_efficient"){.+.+.+}, at: [<ffffffff81474dbf>] set_work_data kernel/workqueue.c:617 [inline]
 #0:  ("events_power_efficient"){.+.+.+}, at: [<ffffffff81474dbf>] set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
 #0:  ("events_power_efficient"){.+.+.+}, at: [<ffffffff81474dbf>] process_one_work+0xadf/0x1bc0 kernel/workqueue.c:2090
 #1:  ((reg_check_chans).work){+.+...}, at: [<ffffffff81474e12>] process_one_work+0xb32/0x1bc0 kernel/workqueue.c:2094
 #2:  (rtnl_mutex){+.+.+.}, at: [<ffffffff83ea7487>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72
3 locks held by kworker/1:3/1312:
 #0:  ("%s"("ipv6_addrconf")){.+.+..}, at: [<ffffffff81474dbf>] __write_once_size include/linux/compiler.h:279 [inline]
 #0:  ("%s"("ipv6_addrconf")){.+.+..}, at: [<ffffffff81474dbf>] atomic64_set arch/x86/include/asm/atomic64_64.h:33 [inline]
 #0:  ("%s"("ipv6_addrconf")){.+.+..}, at: [<ffffffff81474dbf>] atomic_long_set include/asm-generic/atomic-long.h:56 [inline]
 #0:  ("%s"("ipv6_addrconf")){.+.+..}, at: [<ffffffff81474dbf>] set_work_data kernel/workqueue.c:617 [inline]
 #0:  ("%s"("ipv6_addrconf")){.+.+..}, at: [<ffffffff81474dbf>] set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
 #0:  ("%s"("ipv6_addrconf")){.+.+..}, at: [<ffffffff81474dbf>] process_one_work+0xadf/0x1bc0 kernel/workqueue.c:2090
 #1:  ((addr_chk_work).work){+.+...}, at: [<ffffffff81474e12>] process_one_work+0xb32/0x1bc0 kernel/workqueue.c:2094
 #2:  (rtnl_mutex){+.+.+.}, at: [<ffffffff83ea7487>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72
2 locks held by getty/2978:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff84d712b7>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff826e2bef>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2133
2 locks held by getty/2979:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff84d712b7>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff826e2bef>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2133
2 locks held by getty/2980:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff84d712b7>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff826e2bef>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2133
2 locks held by getty/2981:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff84d712b7>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff826e2bef>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2133
2 locks held by getty/2982:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff84d712b7>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff826e2bef>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2133
2 locks held by getty/2983:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff84d712b7>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff826e2bef>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2133
2 locks held by getty/2984:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff84d712b7>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff826e2bef>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2133
1 lock held by syz-executor0/3047:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff83ea7487>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72
2 locks held by syz-executor2/14197:
 #0:  (&pipe->mutex/1){+.+.+.}, at: [<ffffffff81ab0326>] pipe_lock_nested fs/pipe.c:66 [inline]
 #0:  (&pipe->mutex/1){+.+.+.}, at: [<ffffffff81ab0326>] pipe_lock+0x56/0x70 fs/pipe.c:74
 #1:  (sk_lock-AF_INET){+.+.+.}, at: [<ffffffff84088bce>] lock_sock include/net/sock.h:1461 [inline]
 #1:  (sk_lock-AF_INET){+.+.+.}, at: [<ffffffff84088bce>] tcp_sendpage+0x2e/0x60 net/ipv4/tcp.c:1068
1 lock held by syz-executor2/14224:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff83ea7487>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72
1 lock held by syz-executor2/14245:
 #0:  (&pipe->mutex/1){+.+.+.}, at: [<ffffffff81ab0326>] pipe_lock_nested fs/pipe.c:66 [inline]
 #0:  (&pipe->mutex/1){+.+.+.}, at: [<ffffffff81ab0326>] pipe_lock+0x56/0x70 fs/pipe.c:74
2 locks held by syz-executor2/14252:
 #0:  (&pipe->mutex/1){+.+.+.}, at: [<ffffffff81ab0326>] pipe_lock_nested fs/pipe.c:66 [inline]
 #0:  (&pipe->mutex/1){+.+.+.}, at: [<ffffffff81ab0326>] pipe_lock+0x56/0x70 fs/pipe.c:74
 #1:  (sk_lock-AF_INET){+.+.+.}, at: [<ffffffff84088bce>] lock_sock include/net/sock.h:1461 [inline]
 #1:  (sk_lock-AF_INET){+.+.+.}, at: [<ffffffff84088bce>] tcp_sendpage+0x2e/0x60 net/ipv4/tcp.c:1068
1 lock held by syz-executor2/14269:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff83ea7487>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72
1 lock held by syz-executor2/14278:
 #0:  (&pipe->mutex/1){+.+.+.}, at: [<ffffffff81ab0326>] pipe_lock_nested fs/pipe.c:66 [inline]
 #0:  (&pipe->mutex/1){+.+.+.}, at: [<ffffffff81ab0326>] pipe_lock+0x56/0x70 fs/pipe.c:74
1 lock held by syz-executor6/14241:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff83ea7487>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72
1 lock held by syz-executor6/14262:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff83ea7487>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72
1 lock held by syz-executor0/14289:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff83ea7487>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72
1 lock held by syz-executor1/14283:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff83eb398c>] rtnl_lock net/core/rtnetlink.c:72 [inline]
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff83eb398c>] rtnetlink_rcv_msg+0x65c/0x1090 net/core/rtnetlink.c:4241
1 lock held by syz-executor1/14294:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff83ea7487>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72
1 lock held by syz-executor1/14318:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff83ea7487>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72

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

NMI backtrace for cpu 1
CPU: 1 PID: 636 Comm: khungtaskd Not tainted 4.13.0-rc5+ #17
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:16 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:52
 nmi_cpu_backtrace+0x20e/0x240 lib/nmi_backtrace.c:102
 nmi_trigger_cpumask_backtrace+0x122/0x180 lib/nmi_backtrace.c:61
 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 trigger_all_cpu_backtrace include/linux/nmi.h:105 [inline]
 check_hung_task kernel/hung_task.c:132 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:190 [inline]
 watchdog+0x90c/0xd60 kernel/hung_task.c:249
 kthread+0x35e/0x430 kernel/kthread.c:231
 ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:425
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at pc 0xffffffff84d71f26