INFO: task kworker/1:0:17 blocked for more than 120 seconds. Not tainted 4.15.0+ #221 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/1:0 D23088 17 2 0x80000000 Workqueue: events_power_efficient reg_check_chans_work Call Trace: context_switch kernel/sched/core.c:2845 [inline] __schedule+0x8eb/0x2060 kernel/sched/core.c:3421 schedule+0xf5/0x430 kernel/sched/core.c:3480 schedule_preempt_disabled+0x10/0x20 kernel/sched/core.c:3538 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0xaad/0x1a80 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 reg_check_chans_work+0xaa/0xff0 net/wireless/reg.c:2017 process_one_work+0xbbf/0x1af0 kernel/workqueue.c:2113 worker_thread+0x223/0x1990 kernel/workqueue.c:2247 kthread+0x33c/0x400 kernel/kthread.c:238 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:542 Showing all locks held in the system: 3 locks held by kworker/1:0/17: #0: ((wq_completion)"events_power_efficient"){+.+.}, at: [<0000000032087618>] process_one_work+0xaaf/0x1af0 kernel/workqueue.c:2084 #1: ((reg_check_chans).work){+.+.}, at: [<00000000af7905ab>] process_one_work+0xb01/0x1af0 kernel/workqueue.c:2088 #2: (rtnl_mutex){+.+.}, at: [<00000000651224fd>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 2 locks held by khungtaskd/758: #0: (rcu_read_lock){....}, at: [<000000007c38d495>] check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] #0: (rcu_read_lock){....}, at: [<000000007c38d495>] watchdog+0x1c5/0xd60 kernel/hung_task.c:249 #1: (tasklist_lock){.+.+}, at: [<00000000c8d12c91>] debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470 3 locks held by kworker/1:2/1724: #0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: [<0000000032087618>] process_one_work+0xaaf/0x1af0 kernel/workqueue.c:2084 #1: ((addr_chk_work).work){+.+.}, at: [<00000000af7905ab>] process_one_work+0xb01/0x1af0 kernel/workqueue.c:2088 #2: (rtnl_mutex){+.+.}, at: [<00000000651224fd>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 1 lock held by rsyslogd/4009: #0: (&f->f_pos_lock){+.+.}, at: [<000000002b57fdfa>] __fdget_pos+0x12b/0x190 fs/file.c:765 2 locks held by getty/4130: #0: (&tty->ldisc_sem){++++}, at: [<00000000ee3e770f>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000005c3dc02b>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/4131: #0: (&tty->ldisc_sem){++++}, at: [<00000000ee3e770f>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000005c3dc02b>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/4132: #0: (&tty->ldisc_sem){++++}, at: [<00000000ee3e770f>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000005c3dc02b>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/4133: #0: (&tty->ldisc_sem){++++}, at: [<00000000ee3e770f>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000005c3dc02b>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/4134: #0: (&tty->ldisc_sem){++++}, at: [<00000000ee3e770f>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000005c3dc02b>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/4135: #0: (&tty->ldisc_sem){++++}, at: [<00000000ee3e770f>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000005c3dc02b>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/4136: #0: (&tty->ldisc_sem){++++}, at: [<00000000ee3e770f>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000005c3dc02b>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 1 lock held by syz-executor0/4205: #0: (rtnl_mutex){+.+.}, at: [<00000000651224fd>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 1 lock held by syz-executor0/18390: #0: (rtnl_mutex){+.+.}, at: [<00000000651224fd>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 1 lock held by syz-executor2/18357: #0: (sk_lock-AF_INET6){+.+.}, at: [<000000002492b3c6>] lock_sock include/net/sock.h:1463 [inline] #0: (sk_lock-AF_INET6){+.+.}, at: [<000000002492b3c6>] ipv6_getsockopt+0x1c5/0x2e0 net/ipv6/ipv6_sockglue.c:1370 1 lock held by syz-executor2/18374: #0: (rtnl_mutex){+.+.}, at: [<00000000651224fd>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 1 lock held by syz-executor2/18384: #0: (rtnl_mutex){+.+.}, at: [<00000000651224fd>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 1 lock held by syz-executor1/18373: #0: (rtnl_mutex){+.+.}, at: [<00000000651224fd>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 1 lock held by syz-executor1/18388: #0: (rtnl_mutex){+.+.}, at: [<00000000e4502a70>] rtnl_lock net/core/rtnetlink.c:74 [inline] #0: (rtnl_mutex){+.+.}, at: [<00000000e4502a70>] rtnetlink_rcv_msg+0x508/0xb10 net/core/rtnetlink.c:4584 1 lock held by syz-executor1/18403: #0: (rtnl_mutex){+.+.}, at: [<00000000651224fd>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 1 lock held by syz-executor1/18407: #0: (rtnl_mutex){+.+.}, at: [<00000000e4502a70>] rtnl_lock net/core/rtnetlink.c:74 [inline] #0: (rtnl_mutex){+.+.}, at: [<00000000e4502a70>] rtnetlink_rcv_msg+0x508/0xb10 net/core/rtnetlink.c:4584 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 758 Comm: khungtaskd Not tainted 4.15.0+ #221 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:53 nmi_cpu_backtrace+0x1d2/0x210 lib/nmi_backtrace.c:103 nmi_trigger_cpumask_backtrace+0x122/0x180 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:138 [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+0x33c/0x400 kernel/kthread.c:238 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:542 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54