INFO: task kworker/u4:2:28 blocked for more than 140 seconds. Not tainted 5.0.0-rc2-next-20190116 #13 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/u4:2 D19000 28 2 0x80000000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:2834 [inline] __schedule+0x897/0x1e60 kernel/sched/core.c:3475 schedule+0xfe/0x350 kernel/sched/core.c:3519 exp_funnel_lock kernel/rcu/tree_exp.h:321 [inline] synchronize_rcu_expedited+0x8fe/0xa30 kernel/rcu/tree_exp.h:771 synchronize_net+0x3b/0x60 net/core/dev.c:9162 rollback_registered_many+0x784/0x1370 net/core/dev.c:8089 unregister_netdevice_many.part.0+0x8e/0x470 net/core/dev.c:9207 unregister_netdevice_many+0xba/0x120 net/core/dev.c:9206 sit_exit_batch_net+0x5f1/0x830 net/ipv6/sit.c:1888 ops_exit_list.isra.0+0x105/0x160 net/core/net_namespace.c:156 cleanup_net+0x51d/0xb10 net/core/net_namespace.c:551 process_one_work+0xd0c/0x1ce0 kernel/workqueue.c:2153 worker_thread+0x143/0x14a0 kernel/workqueue.c:2296 kthread+0x357/0x430 kernel/kthread.c:247 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 INFO: task syz-executor0:21212 blocked for more than 140 seconds. Not tainted 5.0.0-rc2-next-20190116 #13 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D26408 21212 20382 0x00000004 Call Trace: context_switch kernel/sched/core.c:2834 [inline] __schedule+0x897/0x1e60 kernel/sched/core.c:3475 schedule+0xfe/0x350 kernel/sched/core.c:3519 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3577 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0xa3b/0x1670 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 tun_detach drivers/net/tun.c:741 [inline] tun_chr_close+0x3f/0x180 drivers/net/tun.c:3436 __fput+0x3c5/0xb10 fs/file_table.c:278 ____fput+0x16/0x20 fs/file_table.c:309 task_work_run+0x1f4/0x2b0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x32a/0x3b0 arch/x86/entry/common.c:166 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath arch/x86/entry/common.c:268 [inline] do_syscall_64+0x696/0x800 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x411c91 Code: 00 00 48 29 d1 48 8b 7c 24 40 4c 8d 04 3a 4c 8b 4c 24 48 4c 01 ca 4c 89 c0 48 89 04 24 48 89 d0 48 89 44 24 08 48 83 e1 f8 48 <89> 4c 24 10 e8 56 0e 00 00 48 8b 44 24 40 48 89 04 24 48 8b 4c 24 RSP: 002b:00007fff7e5b5290 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000411c91 RDX: 0000001b2cb20000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 0000000000000000 R08: ffffffff8139d9c8 R09: 00000000ac090dd9 R10: 00007fff7e5b51c0 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000001 R14: 000000000000002a R15: 0000000000000000 INFO: task syz-executor1:21213 blocked for more than 140 seconds. Not tainted 5.0.0-rc2-next-20190116 #13 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor1 D26600 21213 7826 0x00000004 Call Trace: context_switch kernel/sched/core.c:2834 [inline] __schedule+0x897/0x1e60 kernel/sched/core.c:3475 schedule+0xfe/0x350 kernel/sched/core.c:3519 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3577 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0xa3b/0x1670 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 tun_detach drivers/net/tun.c:741 [inline] tun_chr_close+0x3f/0x180 drivers/net/tun.c:3436 __fput+0x3c5/0xb10 fs/file_table.c:278 ____fput+0x16/0x20 fs/file_table.c:309 task_work_run+0x1f4/0x2b0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x32a/0x3b0 arch/x86/entry/common.c:166 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath arch/x86/entry/common.c:268 [inline] do_syscall_64+0x696/0x800 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x411c91 Code: 00 00 48 29 d1 48 8b 7c 24 40 4c 8d 04 3a 4c 8b 4c 24 48 4c 01 ca 4c 89 c0 48 89 04 24 48 89 d0 48 89 44 24 08 48 83 e1 f8 48 <89> 4c 24 10 e8 56 0e 00 00 48 8b 44 24 40 48 89 04 24 48 8b 4c 24 RSP: 002b:00007fffc7dfdbd0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000411c91 RDX: 0000001b2cd20000 RSI: 0000000000741768 RDI: 0000000000000003 RBP: 0000000000000000 R08: ffffffff8100c353 R09: 00000000ac090dd9 R10: 00007fffc7dfdb00 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000001 R14: 00000000000006b3 R15: 0000000000000001 INFO: task syz-executor4:21222 blocked for more than 140 seconds. Not tainted 5.0.0-rc2-next-20190116 #13 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor4 D26600 21222 3542 0x00000004 Call Trace: context_switch kernel/sched/core.c:2834 [inline] __schedule+0x897/0x1e60 kernel/sched/core.c:3475 schedule+0xfe/0x350 kernel/sched/core.c:3519 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3577 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0xa3b/0x1670 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 tun_detach drivers/net/tun.c:741 [inline] tun_chr_close+0x3f/0x180 drivers/net/tun.c:3436 __fput+0x3c5/0xb10 fs/file_table.c:278 ____fput+0x16/0x20 fs/file_table.c:309 task_work_run+0x1f4/0x2b0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x32a/0x3b0 arch/x86/entry/common.c:166 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath arch/x86/entry/common.c:268 [inline] do_syscall_64+0x696/0x800 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x411c91 Code: 00 00 48 29 d1 48 8b 7c 24 40 4c 8d 04 3a 4c 8b 4c 24 48 4c 01 ca 4c 89 c0 48 89 04 24 48 89 d0 48 89 44 24 08 48 83 e1 f8 48 <89> 4c 24 10 e8 56 0e 00 00 48 8b 44 24 40 48 89 04 24 48 8b 4c 24 RSP: 002b:00007ffd4333ebe0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000411c91 RDX: 0000001b2fc20000 RSI: 0000000000742418 RDI: 0000000000000003 RBP: 0000000000000000 R08: ffffffff8100b034 R09: 00000000ac090dd9 R10: 00007ffd4333eb10 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000001 R14: 000000000000029d R15: 0000000000000004 Showing all locks held in the system: 3 locks held by kworker/0:0/5: #0: 00000000d0e7f510 ((wq_completion)"events"){+.+.}, at: __write_once_size include/linux/compiler.h:224 [inline] #0: 00000000d0e7f510 ((wq_completion)"events"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 00000000d0e7f510 ((wq_completion)"events"){+.+.}, at: atomic64_set include/generated/atomic-instrumented.h:855 [inline] #0: 00000000d0e7f510 ((wq_completion)"events"){+.+.}, at: atomic_long_set include/generated/atomic-long.h:40 [inline] #0: 00000000d0e7f510 ((wq_completion)"events"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 00000000d0e7f510 ((wq_completion)"events"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 00000000d0e7f510 ((wq_completion)"events"){+.+.}, at: process_one_work+0xbc7/0x1ce0 kernel/workqueue.c:2124 #1: 000000004083cb8e (deferred_process_work){+.+.}, at: process_one_work+0xc1d/0x1ce0 kernel/workqueue.c:2128 #2: 000000001ae1a0f5 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 4 locks held by kworker/u4:2/28: #0: 000000006264ef65 ((wq_completion)"%s""netns"){+.+.}, at: __write_once_size include/linux/compiler.h:224 [inline] #0: 000000006264ef65 ((wq_completion)"%s""netns"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 000000006264ef65 ((wq_completion)"%s""netns"){+.+.}, at: atomic64_set include/generated/atomic-instrumented.h:855 [inline] #0: 000000006264ef65 ((wq_completion)"%s""netns"){+.+.}, at: atomic_long_set include/generated/atomic-long.h:40 [inline] #0: 000000006264ef65 ((wq_completion)"%s""netns"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 000000006264ef65 ((wq_completion)"%s""netns"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 000000006264ef65 ((wq_completion)"%s""netns"){+.+.}, at: process_one_work+0xbc7/0x1ce0 kernel/workqueue.c:2124 #1: 00000000d08e768d (net_cleanup_work){+.+.}, at: process_one_work+0xc1d/0x1ce0 kernel/workqueue.c:2128 #2: 000000003d097729 (pernet_ops_rwsem){++++}, at: cleanup_net+0x126/0xb10 net/core/net_namespace.c:518 #3: 000000001ae1a0f5 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 1 lock held by khungtaskd/1039: #0: 00000000c3d9d65e (rcu_read_lock){....}, at: debug_show_all_locks+0xc6/0x41d kernel/locking/lockdep.c:4408 1 lock held by rsyslogd/7697: #0: 00000000acc529f1 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1b3/0x1f0 fs/file.c:796 2 locks held by getty/7788: #0: 000000006148fdb9 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000429f61b1 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7789: #0: 00000000e28af690 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000001770ec3e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7790: #0: 000000002480bc50 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000ddf00e87 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7791: #0: 00000000b4173e2e (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000f8d86879 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7792: #0: 0000000072783bb6 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000036dcd4b4 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7793: #0: 000000000dbddece (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000005ce7916d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7794: #0: 00000000d372253b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000ed820ec1 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 3 locks held by kworker/1:0/3605: #0: 0000000035b53c75 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: __write_once_size include/linux/compiler.h:224 [inline] #0: 0000000035b53c75 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 0000000035b53c75 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: atomic64_set include/generated/atomic-instrumented.h:855 [inline] #0: 0000000035b53c75 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: atomic_long_set include/generated/atomic-long.h:40 [inline] #0: 0000000035b53c75 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 0000000035b53c75 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 0000000035b53c75 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: process_one_work+0xbc7/0x1ce0 kernel/workqueue.c:2124 #1: 0000000005035b6b ((addr_chk_work).work){+.+.}, at: process_one_work+0xc1d/0x1ce0 kernel/workqueue.c:2128 #2: 000000001ae1a0f5 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 1 lock held by syz-executor1/21009: #0: 000000001ae1a0f5 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 1 lock held by syz-executor1/21023: #0: 000000001ae1a0f5 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 1 lock held by syz-executor0/21212: #0: 000000001ae1a0f5 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 1 lock held by syz-executor1/21213: #0: 000000001ae1a0f5 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 1 lock held by syz-executor4/21222: #0: 000000001ae1a0f5 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1039 Comm: khungtaskd Not tainted 5.0.0-rc2-next-20190116 #13 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+0x1db/0x2d0 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:203 [inline] watchdog+0xbbb/0x1170 kernel/hung_task.c:287 kthread+0x357/0x430 kernel/kthread.c:247 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 1 to CPUs 0: