syzbot

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