INFO: task kworker/u4:2:24 blocked for more than 140 seconds. Not tainted 5.0.0-rc7-next-20190222 #41 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/u4:2 D26016 24 2 0x80000000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:2877 [inline] __schedule+0x817/0x1cc0 kernel/sched/core.c:3518 schedule+0x92/0x180 kernel/sched/core.c:3562 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3620 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0x726/0x1310 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 rtnl_lock+0x17/0x20 net/core/rtnetlink.c:76 netdev_run_todo+0x565/0x7d0 net/core/dev.c:8956 rtnl_unlock+0xe/0x10 net/core/rtnetlink.c:116 ip_tunnel_delete_nets+0x423/0x5f0 net/ipv4/ip_tunnel.c:1108 erspan_exit_batch_net+0x23/0x30 net/ipv4/ip_gre.c:1594 ops_exit_list.isra.0+0x105/0x160 net/core/net_namespace.c:156 cleanup_net+0x3fb/0x960 net/core/net_namespace.c:551 process_one_work+0x98e/0x1790 kernel/workqueue.c:2267 worker_thread+0x98/0xe40 kernel/workqueue.c:2413 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/0:1/12: #0: 0000000068aaab66 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: __write_once_size include/linux/compiler.h:224 [inline] #0: 0000000068aaab66 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 0000000068aaab66 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: 0000000068aaab66 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: 0000000068aaab66 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 0000000068aaab66 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 0000000068aaab66 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: process_one_work+0x87e/0x1790 kernel/workqueue.c:2238 #1: 000000000703a42e ((addr_chk_work).work){+.+.}, at: process_one_work+0x8b4/0x1790 kernel/workqueue.c:2242 #2: 0000000084c209d7 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:76 4 locks held by kworker/u4:2/24: #0: 000000000e0d1865 ((wq_completion)"%s""netns"){+.+.}, at: __write_once_size include/linux/compiler.h:224 [inline] #0: 000000000e0d1865 ((wq_completion)"%s""netns"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 000000000e0d1865 ((wq_completion)"%s""netns"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: 000000000e0d1865 ((wq_completion)"%s""netns"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: 000000000e0d1865 ((wq_completion)"%s""netns"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 000000000e0d1865 ((wq_completion)"%s""netns"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 000000000e0d1865 ((wq_completion)"%s""netns"){+.+.}, at: process_one_work+0x87e/0x1790 kernel/workqueue.c:2238 #1: 00000000a77fab50 (net_cleanup_work){+.+.}, at: process_one_work+0x8b4/0x1790 kernel/workqueue.c:2242 #2: 0000000009b11859 (pernet_ops_rwsem){++++}, at: cleanup_net+0xae/0x960 net/core/net_namespace.c:518 #3: 0000000084c209d7 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:76 1 lock held by khungtaskd/1043: #0: 000000001b9140ae (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:4382 3 locks held by kworker/1:2/3479: #0: 00000000142436fc ((wq_completion)"events"){+.+.}, at: __write_once_size include/linux/compiler.h:224 [inline] #0: 00000000142436fc ((wq_completion)"events"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 00000000142436fc ((wq_completion)"events"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: 00000000142436fc ((wq_completion)"events"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: 00000000142436fc ((wq_completion)"events"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 00000000142436fc ((wq_completion)"events"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 00000000142436fc ((wq_completion)"events"){+.+.}, at: process_one_work+0x87e/0x1790 kernel/workqueue.c:2238 #1: 000000002b45a44a (deferred_process_work){+.+.}, at: process_one_work+0x8b4/0x1790 kernel/workqueue.c:2242 #2: 0000000084c209d7 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:76 1 lock held by rsyslogd/7658: #0: 00000000a8014dfd (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 2 locks held by getty/7748: #0: 00000000d90bea39 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000b4a7d6a2 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7749: #0: 00000000733acb89 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000088d7946 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7750: #0: 00000000d00e1b73 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000008c80013f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7751: #0: 000000005ce24883 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000176c38df (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7752: #0: 00000000277c74cf (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000a2705581 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7753: #0: 00000000fc693303 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000002f4d74ab (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7754: #0: 00000000e23076bf (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000c2e2ef77 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 3 locks held by kworker/0:4/7800: #0: 00000000142436fc ((wq_completion)"events"){+.+.}, at: __write_once_size include/linux/compiler.h:224 [inline] #0: 00000000142436fc ((wq_completion)"events"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 00000000142436fc ((wq_completion)"events"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: 00000000142436fc ((wq_completion)"events"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: 00000000142436fc ((wq_completion)"events"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 00000000142436fc ((wq_completion)"events"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 00000000142436fc ((wq_completion)"events"){+.+.}, at: process_one_work+0x87e/0x1790 kernel/workqueue.c:2238 #1: 00000000f4213d12 ((linkwatch_work).work){+.+.}, at: process_one_work+0x8b4/0x1790 kernel/workqueue.c:2242 #2: 0000000084c209d7 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:76 1 lock held by syz-executor.5/13300: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1043 Comm: khungtaskd Not tainted 5.0.0-rc7-next-20190222 #41 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+0x9b2/0xeb0 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: