INFO: task syz-executor.4:21134 blocked for more than 143 seconds. Not tainted 5.2.0+ #20 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D25928 21134 7862 0x00004004 Call Trace: context_switch kernel/sched/core.c:3252 [inline] __schedule+0x655/0x9e0 kernel/sched/core.c:3878 schedule+0x131/0x1d0 kernel/sched/core.c:3942 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:163 [inline] prepare_exit_to_usermode+0x43a/0x560 arch/x86/entry/common.c:194 syscall_return_slowpath+0x110/0x440 arch/x86/entry/common.c:274 do_syscall_64+0x126/0x140 arch/x86/entry/common.c:299 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4134b1 Code: cf 48 c1 e9 03 4c 8b 05 a5 1c 3b 01 48 c1 ef 05 49 29 f8 49 8d 78 ff 48 83 e1 03 48 83 fa 10 0f 84 a7 04 00 00 44 0f b6 43 17 <41> f6 c0 40 0f 85 58 04 00 00 4c 8b 03 48 8b 44 24 68 49 39 c0 0f RSP: 002b:00007ffc13910c70 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000005 RCX: 00000000004134b1 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 0000000000000001 R08: 00000000813843ca R09: ffffffffffffffff R10: 00007ffc13910d50 R11: 0000000000000293 R12: 000000000075bf20 R13: 00000000000658ed R14: 00000000007605b8 R15: ffffffffffffffff Showing all locks held in the system: 2 locks held by kworker/u4:3/157: #0: 000000002294849d (&rq->lock){-.-.}, at: idle_balance kernel/sched/fair.c:9815 [inline] #0: 000000002294849d (&rq->lock){-.-.}, at: pick_next_task_fair+0xa98/0x1e70 kernel/sched/fair.c:6852 #1: 0000000062f71ad4 (rcu_read_lock){....}, at: rcu_lock_acquire+0x4/0x30 include/linux/rcupdate.h:207 1 lock held by khungtaskd/1047: #0: 0000000062f71ad4 (rcu_read_lock){....}, at: rcu_lock_acquire+0x4/0x30 include/linux/rcupdate.h:207 1 lock held by rsyslogd/7721: #0: 00000000c3dce1fb (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x243/0x2e0 fs/file.c:801 2 locks held by getty/7811: #0: 00000000cf110ba1 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272 #1: 00000000b6650289 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ee/0x1c80 drivers/tty/n_tty.c:2156 2 locks held by getty/7812: #0: 00000000d665f502 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272 #1: 00000000e9ed4412 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ee/0x1c80 drivers/tty/n_tty.c:2156 2 locks held by getty/7813: #0: 00000000902597bc (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272 #1: 00000000464dec36 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ee/0x1c80 drivers/tty/n_tty.c:2156 2 locks held by getty/7814: #0: 000000003abe2cc0 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272 #1: 00000000e70c61b8 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ee/0x1c80 drivers/tty/n_tty.c:2156 2 locks held by getty/7815: #0: 00000000db0afa6d (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272 #1: 00000000c4d6e022 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ee/0x1c80 drivers/tty/n_tty.c:2156 2 locks held by getty/7816: #0: 00000000e4ad2fac (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272 #1: 000000008918f71f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ee/0x1c80 drivers/tty/n_tty.c:2156 2 locks held by getty/7817: #0: 00000000031340ad (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272 #1: 00000000445189db (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ee/0x1c80 drivers/tty/n_tty.c:2156 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1047 Comm: khungtaskd Not tainted 5.2.0+ #20 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+0x131/0x240 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 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60