INFO: task syz-executor.5:20980 can't die for more than 143 seconds. syz-executor.5 D28152 20980 9237 0x00004004 Call Trace: context_switch kernel/sched/core.c:2818 [inline] __schedule+0x755/0x1580 kernel/sched/core.c:3444 schedule+0xa8/0x270 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 kthread_stop+0x131/0x730 kernel/kthread.c:559 io_sq_thread_stop fs/io_uring.c:2249 [inline] io_finish_async+0x73/0x140 fs/io_uring.c:2256 io_ring_ctx_free fs/io_uring.c:2767 [inline] io_ring_ctx_wait_and_kill+0x133/0x600 fs/io_uring.c:2831 io_uring_release+0x42/0x50 fs/io_uring.c:2839 __fput+0x2ff/0x890 fs/file_table.c:280 ____fput+0x16/0x20 fs/file_table.c:313 task_work_run+0x145/0x1c0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x280/0x2d0 arch/x86/entry/common.c:168 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:279 [inline] do_syscall_64+0x5a9/0x6a0 arch/x86/entry/common.c:304 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x412fb1 Code: 75 52 0f b6 19 48 ff c1 0f ba e3 00 73 de 48 89 54 24 20 89 5c 24 1c 48 89 4c 24 38 48 8b 44 24 68 48 8d 0c 02 48 8b 5c 24 60 <48> 8d 34 1a 48 8b 09 48 89 4c 24 08 48 89 34 24 e8 9a ea ff ff 48 RSP: 002b:00007ffde867b780 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000007 RCX: 0000000000412fb1 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000006 RBP: 0000000000000001 R08: 0000000024b01404 R09: 0000000024b01408 R10: 00007ffde867b860 R11: 0000000000000293 R12: 000000000075c9a0 R13: 000000000075c9a0 R14: 0000000000082eee R15: 000000000075bfd4 INFO: task syz-executor.5:20980 blocked for more than 143 seconds. Not tainted 5.2.0-rc5-next-20190620 #19 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D28152 20980 9237 0x00004004 Call Trace: context_switch kernel/sched/core.c:2818 [inline] __schedule+0x755/0x1580 kernel/sched/core.c:3444 schedule+0xa8/0x270 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 kthread_stop+0x131/0x730 kernel/kthread.c:559 io_sq_thread_stop fs/io_uring.c:2249 [inline] io_finish_async+0x73/0x140 fs/io_uring.c:2256 io_ring_ctx_free fs/io_uring.c:2767 [inline] io_ring_ctx_wait_and_kill+0x133/0x600 fs/io_uring.c:2831 io_uring_release+0x42/0x50 fs/io_uring.c:2839 __fput+0x2ff/0x890 fs/file_table.c:280 ____fput+0x16/0x20 fs/file_table.c:313 task_work_run+0x145/0x1c0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x280/0x2d0 arch/x86/entry/common.c:168 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:279 [inline] do_syscall_64+0x5a9/0x6a0 arch/x86/entry/common.c:304 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x412fb1 Code: 75 52 0f b6 19 48 ff c1 0f ba e3 00 73 de 48 89 54 24 20 89 5c 24 1c 48 89 4c 24 38 48 8b 44 24 68 48 8d 0c 02 48 8b 5c 24 60 <48> 8d 34 1a 48 8b 09 48 89 4c 24 08 48 89 34 24 e8 9a ea ff ff 48 RSP: 002b:00007ffde867b780 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000007 RCX: 0000000000412fb1 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000006 RBP: 0000000000000001 R08: 0000000024b01404 R09: 0000000024b01408 R10: 00007ffde867b860 R11: 0000000000000293 R12: 000000000075c9a0 R13: 000000000075c9a0 R14: 0000000000082eee R15: 000000000075bfd4 Showing all locks held in the system: 3 locks held by kworker/u4:2/26: #0: 00000000b26d8001 (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1158 [inline] #0: 00000000b26d8001 (&rq->lock){-.-.}, at: __schedule+0x1f5/0x1580 kernel/sched/core.c:3396 #1: 00000000883817ee (rcu_read_lock){....}, at: __update_idle_core+0x45/0x3f0 kernel/sched/fair.c:5785 #2: 00000000a8357777 (&base->lock){-.-.}, at: lock_timer_base+0x56/0x1b0 kernel/time/timer.c:932 1 lock held by khungtaskd/1044: #0: 00000000883817ee (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:5262 2 locks held by getty/9182: #0: 000000000153ec53 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000db80da00 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/9183: #0: 000000000f4bd442 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000000bbeea47 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/9184: #0: 000000003711d573 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000034e68fdd (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/9185: #0: 000000009772cd2d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000586d982c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/9186: #0: 000000009f52889c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000008fadd855 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/9187: #0: 000000001ca19a47 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000002d4eb8d7 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/9188: #0: 000000000880f388 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000cb8f40ee (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1044 Comm: khungtaskd Not tainted 5.2.0-rc5-next-20190620 #19 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+0x70/0xb2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x22f/0x27f 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:249 [inline] watchdog+0xc54/0x1320 kernel/hung_task.c:333 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60