INFO: task syz-executor.1:12389 blocked for more than 143 seconds. Not tainted 5.2.0+ #53 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D28152 12389 9426 0x00004004 Call Trace: context_switch kernel/sched/core.c:3252 [inline] __schedule+0x755/0x1580 kernel/sched/core.c:3878 schedule+0xa8/0x270 kernel/sched/core.c:3942 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:185 [inline] exit_to_usermode_loop+0x316/0x380 arch/x86/entry/common.c:163 prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline] syscall_return_slowpath arch/x86/entry/common.c:274 [inline] do_syscall_64+0x5a9/0x6a0 arch/x86/entry/common.c:299 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x413501 Code: 39 0f 87 d1 03 00 00 49 89 f2 45 31 db 45 31 e4 eb 27 4d 8d 6b 08 44 0f b6 36 49 89 cf 4c 89 d9 49 d3 e6 48 83 f9 40 4c 89 f9 <4d> 19 ff 4d 21 f7 4d 09 fc 48 ff c6 4d 89 eb 4d 39 cb 72 d4 4c 89 RSP: 002b:00007fff0146e030 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000413501 RDX: 0000001b30d20000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 0000000000000001 R08: 0000001b31d20000 R09: 00007f139e2ed3e8 R10: 0000000000000001 R11: 0000000000000293 R12: 000000000075bf20 R13: 000000000002c0a1 R14: 00000000007604b0 R15: ffffffffffffffff Showing all locks held in the system: 3 locks held by kworker/u4:1/21: #0: 000000005532b085 (&rq->lock){-.-.}, at: idle_balance kernel/sched/fair.c:9815 [inline] #0: 000000005532b085 (&rq->lock){-.-.}, at: pick_next_task_fair+0xc44/0x1a60 kernel/sched/fair.c:6852 #1: 00000000ede0504c (rcu_read_lock){....}, at: __update_idle_core+0x45/0x3f0 kernel/sched/fair.c:5820 #2: 0000000043c68db9 (&base->lock){..-.}, at: lock_timer_base+0x56/0x1b0 kernel/time/timer.c:932 1 lock held by khungtaskd/1049: #0: 00000000ede0504c (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:5257 3 locks held by rs:main Q:Reg/9257: 1 lock held by rsyslogd/9259: 2 locks held by getty/9381: #0: 000000008dc53839 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000003e69e89d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/9382: #0: 000000006fafaf07 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000006496ef85 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/9383: #0: 00000000f01bece9 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000000fca06ba (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/9384: #0: 00000000aff2ae29 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000a4d948b1 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/9385: #0: 00000000ebcd573b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000088f61173 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/9386: #0: 00000000baeda5ac (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000b167d432 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/9387: #0: 00000000cf8fa0dd (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000001f94c855 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1049 Comm: khungtaskd Not tainted 5.2.0+ #53 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+0x23b/0x28b 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:205 [inline] watchdog+0x9d0/0xef0 kernel/hung_task.c:289 kthread+0x361/0x430 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