INFO: task kworker/u4:6:14660 blocked for more than 143 seconds. Not tainted 5.1.0-rc6+ #160 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/u4:6 D25072 14660 2 0x80000000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:2877 [inline] __schedule+0x813/0x1cc0 kernel/sched/core.c:3518 schedule+0x92/0x180 kernel/sched/core.c:3562 exp_funnel_lock kernel/rcu/tree_exp.h:308 [inline] synchronize_rcu_expedited+0x54e/0x5b0 kernel/rcu/tree_exp.h:758 synchronize_net+0x3b/0x60 net/core/dev.c:9277 dev_deactivate_many+0x46f/0xb60 net/sched/sch_generic.c:1203 __dev_close_many+0x13d/0x300 net/core/dev.c:1480 dev_close_many+0x25b/0x6f0 net/core/dev.c:1518 rollback_registered_many+0x43b/0xfd0 net/core/dev.c:8191 unregister_netdevice_many.part.0+0x1b/0x1f0 net/core/dev.c:9322 unregister_netdevice_many+0x3b/0x50 net/core/dev.c:9321 ip6gre_exit_batch_net+0x535/0x750 net/ipv6/ip6_gre.c:1608 ops_exit_list.isra.0+0x105/0x160 net/core/net_namespace.c:156 cleanup_net+0x3fb/0x960 net/core/net_namespace.c:552 process_one_work+0x98e/0x1790 kernel/workqueue.c:2269 worker_thread+0x98/0xe40 kernel/workqueue.c:2415 kthread+0x357/0x430 kernel/kthread.c:253 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Showing all locks held in the system: 3 locks held by kworker/u4:2/30: #0: 000000004b9f8670 (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1168 [inline] #0: 000000004b9f8670 (&rq->lock){-.-.}, at: __schedule+0x1f8/0x1cc0 kernel/sched/core.c:3456 #1: 000000002b6a6662 (rcu_read_lock){....}, at: __update_idle_core+0x45/0x3f0 kernel/sched/fair.c:6084 #2: 000000007939ecaa (&base->lock){-.-.}, at: lock_timer_base+0x56/0x1b0 kernel/time/timer.c:937 1 lock held by khungtaskd/1042: #0: 000000002b6a6662 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:5057 1 lock held by rsyslogd/7487: #0: 0000000079bd213a (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 2 locks held by getty/7577: #0: 0000000087916c4e (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000006b3cbd24 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7578: #0: 00000000f7a767cd (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000032b1e293 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7579: #0: 00000000c08b7c64 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000029b3f11b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7580: #0: 00000000bd3e4c89 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000008151f8b5 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7581: #0: 000000007c66a391 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000003fd931d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7582: #0: 000000004c00d9a8 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000006c648cae (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7583: #0: 00000000a32bd59e (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000980d2b8a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 3 locks held by kworker/1:3/7622: #0: 00000000f8d8a372 ((wq_completion)ipv6_addrconf){+.+.}, at: __write_once_size include/linux/compiler.h:220 [inline] #0: 00000000f8d8a372 ((wq_completion)ipv6_addrconf){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 00000000f8d8a372 ((wq_completion)ipv6_addrconf){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: 00000000f8d8a372 ((wq_completion)ipv6_addrconf){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: 00000000f8d8a372 ((wq_completion)ipv6_addrconf){+.+.}, at: set_work_data kernel/workqueue.c:619 [inline] #0: 00000000f8d8a372 ((wq_completion)ipv6_addrconf){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: 00000000f8d8a372 ((wq_completion)ipv6_addrconf){+.+.}, at: process_one_work+0x87e/0x1790 kernel/workqueue.c:2240 #1: 00000000c2669f83 ((addr_chk_work).work){+.+.}, at: process_one_work+0x8b4/0x1790 kernel/workqueue.c:2244 #2: 00000000ccabf23a (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:76 4 locks held by kworker/u4:6/14660: #0: 00000000491ad30a ((wq_completion)netns){+.+.}, at: __write_once_size include/linux/compiler.h:220 [inline] #0: 00000000491ad30a ((wq_completion)netns){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 00000000491ad30a ((wq_completion)netns){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: 00000000491ad30a ((wq_completion)netns){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: 00000000491ad30a ((wq_completion)netns){+.+.}, at: set_work_data kernel/workqueue.c:619 [inline] #0: 00000000491ad30a ((wq_completion)netns){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: 00000000491ad30a ((wq_completion)netns){+.+.}, at: process_one_work+0x87e/0x1790 kernel/workqueue.c:2240 #1: 00000000931a7e80 (net_cleanup_work){+.+.}, at: process_one_work+0x8b4/0x1790 kernel/workqueue.c:2244 #2: 000000003a5a6bb4 (pernet_ops_rwsem){++++}, at: cleanup_net+0xae/0x960 net/core/net_namespace.c:519 #3: 00000000ccabf23a (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:76 1 lock held by syz-executor.2/20975: #0: 00000000ccabf23a (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:76 1 lock held by syz-executor.2/20980: #0: 00000000ccabf23a (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:76 1 lock held by syz-executor.2/20987: #0: 00000000ccabf23a (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:76 1 lock held by syz-executor.2/20994: #0: 00000000ccabf23a (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:76 1 lock held by syz-executor.2/21019: #0: 00000000ccabf23a (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:76 1 lock held by syz-executor.2/21020: #0: 00000000ccabf23a (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:76 1 lock held by syz-executor.2/21021: #0: 00000000ccabf23a (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:76 1 lock held by syz-executor.2/21023: #0: 00000000ccabf23a (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:76 1 lock held by syz-executor.0/21001: #0: 00000000ccabf23a (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:76 1 lock held by syz-executor.0/21009: #0: 00000000ccabf23a (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:76 1 lock held by syz-executor.0/21012: #0: 00000000ccabf23a (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:76 1 lock held by syz-executor.0/21024: #0: 00000000ccabf23a (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:76 2 locks held by syz-executor.1/21015: #0: 000000009aff0fbb (sk_lock-AF_PACKET){+.+.}, at: lock_sock include/net/sock.h:1525 [inline] #0: 000000009aff0fbb (sk_lock-AF_PACKET){+.+.}, at: packet_setsockopt+0x14a/0x2e70 net/packet/af_packet.c:3634 #1: 00000000ccabf23a (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:76 1 lock held by syz-executor.4/21014: #0: 00000000ccabf23a (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:76 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1042 Comm: khungtaskd Not tainted 5.1.0-rc6+ #160 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1be/0x236 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:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:204 [inline] watchdog+0x9b7/0xec0 kernel/hung_task.c:288 kthread+0x357/0x430 kernel/kthread.c:253 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 0 to CPUs 1: