INFO: task syz-executor.3:8757 blocked for more than 143 seconds. Not tainted 5.2.0-rc6+ #10 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D25760 8757 8073 0x00004004 Call Trace: context_switch kernel/sched/core.c:2818 [inline] __schedule+0x658/0x9e0 kernel/sched/core.c:3445 schedule+0x131/0x1d0 kernel/sched/core.c:3509 schedule_timeout+0x9a/0x2b0 kernel/time/timer.c:1783 do_wait_for_common+0x35e/0x5a0 kernel/sched/completion.c:83 __wait_for_common kernel/sched/completion.c:104 [inline] wait_for_common kernel/sched/completion.c:115 [inline] wait_for_completion+0x47/0x60 kernel/sched/completion.c:136 kthread_stop+0xb4/0x150 kernel/kthread.c:559 io_sq_thread_stop fs/io_uring.c:2252 [inline] io_finish_async fs/io_uring.c:2259 [inline] io_ring_ctx_free fs/io_uring.c:2770 [inline] io_ring_ctx_wait_and_kill+0x268/0x880 fs/io_uring.c:2834 io_uring_release+0x5d/0x70 fs/io_uring.c:2842 __fput+0x2e4/0x740 fs/file_table.c:280 ____fput+0x15/0x20 fs/file_table.c:313 task_work_run+0x17e/0x1b0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:185 [inline] exit_to_usermode_loop arch/x86/entry/common.c:168 [inline] prepare_exit_to_usermode+0x402/0x4f0 arch/x86/entry/common.c:199 syscall_return_slowpath+0x110/0x440 arch/x86/entry/common.c:279 do_syscall_64+0x126/0x140 arch/x86/entry/common.c:304 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x413201 Code: 48 89 54 24 10 48 85 d2 0f 86 cd 00 00 00 48 89 d3 31 d2 48 f7 f3 48 c7 41 30 00 00 00 00 48 c7 41 40 ff ff ff ff 48 89 41 38 <48> c7 41 48 00 00 00 00 48 c7 41 50 00 00 00 00 48 8b 41 38 48 89 RSP: 002b:00007ffde96c88e0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000009 RCX: 0000000000413201 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000008 RBP: 0000000000000000 R08: ffffffffffffffff R09: ffffffffffffffff R10: 00007ffde96c89c0 R11: 0000000000000293 R12: 0000000000760a80 R13: 0000000000106665 R14: 0000000000106692 R15: ffffffffffffffff Showing all locks held in the system: 1 lock held by khungtaskd/1042: #0: 000000007fbca72a (rcu_read_lock){....}, at: rcu_lock_acquire+0x4/0x30 include/linux/rcupdate.h:207 2 locks held by rsyslogd/7939: #0: 00000000e37d0abc (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x243/0x2e0 fs/file.c:801 #1: 000000007fbca72a (rcu_read_lock){....}, at: __debug_check_no_obj_freed lib/debugobjects.c:776 [inline] #1: 000000007fbca72a (rcu_read_lock){....}, at: debug_check_no_obj_freed+0xa1/0x740 lib/debugobjects.c:817 2 locks held by getty/8029: #0: 000000003312c716 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272 #1: 000000000607c3d0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ee/0x1c80 drivers/tty/n_tty.c:2156 2 locks held by getty/8030: #0: 00000000dce4f968 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272 #1: 00000000e6037814 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ee/0x1c80 drivers/tty/n_tty.c:2156 2 locks held by getty/8031: #0: 000000001b18eabb (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272 #1: 000000006831ea89 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ee/0x1c80 drivers/tty/n_tty.c:2156 2 locks held by getty/8032: #0: 00000000f56511ad (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272 #1: 00000000c9daf2d0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ee/0x1c80 drivers/tty/n_tty.c:2156 2 locks held by getty/8033: #0: 0000000076f1e6c6 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272 #1: 00000000ac7b47de (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ee/0x1c80 drivers/tty/n_tty.c:2156 2 locks held by getty/8034: #0: 00000000f130d83c (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272 #1: 00000000812c2ae3 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ee/0x1c80 drivers/tty/n_tty.c:2156 2 locks held by getty/8035: #0: 000000000c9f7a1f (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272 #1: 000000004c59ddf2 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ee/0x1c80 drivers/tty/n_tty.c:2156 3 locks held by kworker/u4:5/16745: #0: 0000000070303fa5 (&rq->lock){-.-.}, at: idle_balance kernel/sched/fair.c:10083 [inline] #0: 0000000070303fa5 (&rq->lock){-.-.}, at: pick_next_task_fair+0x9f8/0x1bf0 kernel/sched/fair.c:7090 #1: 000000007fbca72a (rcu_read_lock){....}, at: rcu_lock_acquire+0x4/0x30 include/linux/rcupdate.h:207 #2: 00000000846b15fb (&base->lock){-.-.}, at: lock_timer_base kernel/time/timer.c:932 [inline] #2: 00000000846b15fb (&base->lock){-.-.}, at: __mod_timer+0x21e/0x1640 kernel/time/timer.c:1004 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1042 Comm: khungtaskd Not tainted 5.2.0-rc6+ #10 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+0x1d8/0x2f8 lib/dump_stack.c:113 nmi_cpu_backtrace+0x89/0x160 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x125/0x230 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x10/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace+0x17/0x20 include/linux/nmi.h:146 check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xbb9/0xbd0 kernel/hung_task.c:289 kthread+0x325/0x350 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60