INFO: task kworker/u4:3:28457 blocked for more than 143 seconds. Not tainted 5.1.0-rc5-next-20190417 #27 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/u4:3 D25464 28457 2 0x80004000 Workqueue: events_unbound fsnotify_connector_destroy_workfn Call Trace: context_switch kernel/sched/core.c:2817 [inline] __schedule+0x7d1/0x15c0 kernel/sched/core.c:3444 schedule+0xa8/0x260 kernel/sched/core.c:3508 schedule_timeout+0x717/0xc50 kernel/time/timer.c:1783 do_wait_for_common kernel/sched/completion.c:83 [inline] __wait_for_common kernel/sched/completion.c:104 [inline] wait_for_common kernel/sched/completion.c:115 [inline] wait_for_completion+0x29c/0x440 kernel/sched/completion.c:136 __synchronize_srcu+0x197/0x250 kernel/rcu/srcutree.c:921 synchronize_srcu_expedited kernel/rcu/srcutree.c:946 [inline] synchronize_srcu+0x239/0x3e8 kernel/rcu/srcutree.c:997 fsnotify_connector_destroy_workfn+0x4e/0xa0 fs/notify/mark.c:177 process_one_work+0x98e/0x1790 kernel/workqueue.c:2268 worker_thread+0x98/0xe40 kernel/workqueue.c:2414 kthread+0x357/0x430 kernel/kthread.c:254 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 INFO: task kworker/u4:5:16202 blocked for more than 143 seconds. Not tainted 5.1.0-rc5-next-20190417 #27 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/u4:5 D26056 16202 2 0x80004000 Workqueue: events_unbound fsnotify_mark_destroy_workfn Call Trace: context_switch kernel/sched/core.c:2817 [inline] __schedule+0x7d1/0x15c0 kernel/sched/core.c:3444 schedule+0xa8/0x260 kernel/sched/core.c:3508 schedule_timeout+0x717/0xc50 kernel/time/timer.c:1783 do_wait_for_common kernel/sched/completion.c:83 [inline] __wait_for_common kernel/sched/completion.c:104 [inline] wait_for_common kernel/sched/completion.c:115 [inline] wait_for_completion+0x29c/0x440 kernel/sched/completion.c:136 __synchronize_srcu+0x197/0x250 kernel/rcu/srcutree.c:921 synchronize_srcu+0x2dc/0x3e8 kernel/rcu/srcutree.c:999 fsnotify_mark_destroy_workfn+0x110/0x3b0 fs/notify/mark.c:827 process_one_work+0x98e/0x1790 kernel/workqueue.c:2268 worker_thread+0x98/0xe40 kernel/workqueue.c:2414 kthread+0x357/0x430 kernel/kthread.c:254 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 INFO: task syz-executor.0:9608 blocked for more than 144 seconds. Not tainted 5.1.0-rc5-next-20190417 #27 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D24176 9608 1 0x00000004 Call Trace: context_switch kernel/sched/core.c:2817 [inline] __schedule+0x7d1/0x15c0 kernel/sched/core.c:3444 schedule+0xa8/0x260 kernel/sched/core.c:3508 synchronize_rcu_expedited+0x431/0x5b0 kernel/rcu/tree_exp.h:807 namespace_unlock+0x108/0x130 fs/namespace.c:1384 do_umount fs/namespace.c:1605 [inline] ksys_umount+0x73e/0xf00 fs/namespace.c:1702 __do_sys_umount fs/namespace.c:1713 [inline] __se_sys_umount fs/namespace.c:1711 [inline] __x64_sys_umount+0x54/0x80 fs/namespace.c:1711 do_syscall_64+0x103/0x670 arch/x86/entry/common.c:298 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45b677 Code: Bad RIP value. RSP: 002b:00007ffd7aeabe98 EFLAGS: 00000206 ORIG_RAX: 00000000000000a6 RAX: ffffffffffffffda RBX: 000000000031161e RCX: 000000000045b677 RDX: 0000000000403270 RSI: 0000000000000002 RDI: 00007ffd7aeabf40 RBP: 00000000000006f3 R08: 0000000000000000 R09: 000000000000000b R10: 0000000000000005 R11: 0000000000000206 R12: 00007ffd7aeacfd0 R13: 00005555565ff940 R14: 0000000000000000 R15: 00007ffd7aeacfd0 Showing all locks held in the system: 1 lock held by khungtaskd/1043: #0: 000000004f5abddf (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:5046 4 locks held by rs:main Q:Reg/7663: 1 lock held by rsyslogd/7665: #0: 000000004a75eed2 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 2 locks held by getty/7755: #0: 0000000073611a17 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000004d084c35 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7756: #0: 00000000bbde09ab (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000083582ee3 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7757: #0: 00000000eea3aaca (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000007792b1db (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7758: #0: 000000001e6380b3 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000478de0bd (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7759: #0: 000000000bc72a0f (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000182d8c9b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7760: #0: 000000007c27174a (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000077ed7bd0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7761: #0: 000000003f377766 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000f0ff7d63 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by kworker/u4:3/28457: #0: 00000000f6fe4cf1 ((wq_completion)events_unbound){+.+.}, at: __write_once_size include/linux/compiler.h:224 [inline] #0: 00000000f6fe4cf1 ((wq_completion)events_unbound){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 00000000f6fe4cf1 ((wq_completion)events_unbound){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: 00000000f6fe4cf1 ((wq_completion)events_unbound){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: 00000000f6fe4cf1 ((wq_completion)events_unbound){+.+.}, at: set_work_data kernel/workqueue.c:619 [inline] #0: 00000000f6fe4cf1 ((wq_completion)events_unbound){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: 00000000f6fe4cf1 ((wq_completion)events_unbound){+.+.}, at: process_one_work+0x87e/0x1790 kernel/workqueue.c:2239 #1: 000000000d469b77 (connector_reaper_work){+.+.}, at: process_one_work+0x8b4/0x1790 kernel/workqueue.c:2243 2 locks held by kworker/u4:5/16202: #0: 00000000f6fe4cf1 ((wq_completion)events_unbound){+.+.}, at: __write_once_size include/linux/compiler.h:224 [inline] #0: 00000000f6fe4cf1 ((wq_completion)events_unbound){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 00000000f6fe4cf1 ((wq_completion)events_unbound){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: 00000000f6fe4cf1 ((wq_completion)events_unbound){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: 00000000f6fe4cf1 ((wq_completion)events_unbound){+.+.}, at: set_work_data kernel/workqueue.c:619 [inline] #0: 00000000f6fe4cf1 ((wq_completion)events_unbound){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: 00000000f6fe4cf1 ((wq_completion)events_unbound){+.+.}, at: process_one_work+0x87e/0x1790 kernel/workqueue.c:2239 #1: 0000000007f39514 ((reaper_work).work){+.+.}, at: process_one_work+0x8b4/0x1790 kernel/workqueue.c:2243 3 locks held by kworker/1:8/9568: 1 lock held by syz-executor.0/9608: #0: 0000000054e8cd74 (rcu_state.exp_mutex){+.+.}, at: exp_funnel_lock kernel/rcu/tree_exp.h:286 [inline] #0: 0000000054e8cd74 (rcu_state.exp_mutex){+.+.}, at: synchronize_rcu_expedited+0x4ab/0x5b0 kernel/rcu/tree_exp.h:790 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1043 Comm: khungtaskd Not tainted 5.1.0-rc5-next-20190417 #27 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:254 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 0 to CPUs 1: