INFO: task syz-executor955:28810 can't die for more than 143 seconds. syz-executor955 D28160 28810 9014 0x00004004 Call Trace: context_switch kernel/sched/core.c:3385 [inline] __schedule+0x8e1/0x1f30 kernel/sched/core.c:4081 schedule+0xdc/0x2b0 kernel/sched/core.c:4155 schedule_timeout+0x717/0xc50 kernel/time/timer.c:1871 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 io_wq_destroy+0x22a/0x450 fs/io-wq.c:1068 io_finish_async+0x128/0x1b0 fs/io_uring.c:3423 io_ring_ctx_free fs/io_uring.c:4220 [inline] io_ring_ctx_wait_and_kill+0x2b7/0x810 fs/io_uring.c:4293 io_uring_release+0x42/0x50 fs/io_uring.c:4301 __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+0x316/0x380 arch/x86/entry/common.c:164 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline] syscall_return_slowpath arch/x86/entry/common.c:278 [inline] do_syscall_64+0x676/0x790 arch/x86/entry/common.c:304 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x402530 Code: 00 00 58 04 00 00 12 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 b7 03 00 00 20 00 00 00 00 00 00 00 00 00 00 00 <00> 00 00 00 00 00 00 00 e6 04 00 00 12 00 00 00 00 00 00 00 00 00 RSP: 002b:00007ffec599b498 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000402530 RDX: 00000000004024d0 RSI: 0000000020000000 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000004 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000dd9 R13: 00007ffec599b680 R14: 0000000000000004 R15: 0000000000000000 INFO: task syz-executor955:28810 blocked for more than 143 seconds. Not tainted 5.4.0-rc7-next-20191115 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor955 D28160 28810 9014 0x00004004 Call Trace: context_switch kernel/sched/core.c:3385 [inline] __schedule+0x8e1/0x1f30 kernel/sched/core.c:4081 schedule+0xdc/0x2b0 kernel/sched/core.c:4155 schedule_timeout+0x717/0xc50 kernel/time/timer.c:1871 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 io_wq_destroy+0x22a/0x450 fs/io-wq.c:1068 io_finish_async+0x128/0x1b0 fs/io_uring.c:3423 io_ring_ctx_free fs/io_uring.c:4220 [inline] io_ring_ctx_wait_and_kill+0x2b7/0x810 fs/io_uring.c:4293 io_uring_release+0x42/0x50 fs/io_uring.c:4301 __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+0x316/0x380 arch/x86/entry/common.c:164 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline] syscall_return_slowpath arch/x86/entry/common.c:278 [inline] do_syscall_64+0x676/0x790 arch/x86/entry/common.c:304 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x402530 Code: 00 00 58 04 00 00 12 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 b7 03 00 00 20 00 00 00 00 00 00 00 00 00 00 00 <00> 00 00 00 00 00 00 00 e6 04 00 00 12 00 00 00 00 00 00 00 00 00 RSP: 002b:00007ffec599b498 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000402530 RDX: 00000000004024d0 RSI: 0000000020000000 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000004 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000dd9 R13: 00007ffec599b680 R14: 0000000000000004 R15: 0000000000000000 Showing all locks held in the system: 1 lock held by khungtaskd/1080: #0: ffffffff88faccc0 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x279 kernel/locking/lockdep.c:5334 1 lock held by rsyslogd/8893: #0: ffff888095ca7da0 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 2 locks held by getty/8983: #0: ffff88809bea6090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f252e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/8984: #0: ffff8880a1e64090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f212e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/8985: #0: ffff8880a2159090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f392e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/8986: #0: ffff88808f287090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f312e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/8987: #0: ffff8880a1387090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f352e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/8988: #0: ffff88809cf11090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f152e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/8989: #0: ffff88809789f090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f092e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1080 Comm: khungtaskd Not tainted 5.4.0-rc7-next-20191115 #0 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+0x197/0x210 lib/dump_stack.c:118 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:269 [inline] watchdog+0xc8f/0x1350 kernel/hung_task.c:353 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 CPU: 0 PID: 9013 Comm: syz-executor955 Not tainted 5.4.0-rc7-next-20191115 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__lock_acquire+0x292/0x4a00 kernel/locking/lockdep.c:3893 Code: 09 f0 66 41 89 42 20 48 b8 00 00 00 00 00 fc ff df 80 3c 02 00 0f 85 04 34 00 00 48 8b 45 18 49 8d 7a 10 48 89 fa 48 c1 ea 03 <49> 89 42 08 48 b8 00 00 00 00 00 fc ff df 80 3c 02 00 0f 85 69 34 RSP: 0018:ffff88808c5779c0 EFLAGS: 00000806 RAX: ffffffff8758dab2 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 1ffff110127f6d8e RSI: 0000000000000028 RDI: ffff888093fb6c70 RBP: ffff88808c577ad8 R08: 0000000000000001 R09: 0000000000000001 R10: ffff888093fb6c60 R11: ffff888093fb63c0 R12: 0000000000000028 R13: 0000000000000000 R14: ffff8880ae837358 R15: 0000000000000001 FS: 000000000224d940(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000000 CR3: 00000000a45de000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4485 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:151 rq_lock kernel/sched/sched.h:1215 [inline] __schedule+0x232/0x1f30 kernel/sched/core.c:4029 schedule+0xdc/0x2b0 kernel/sched/core.c:4155 freezable_schedule include/linux/freezer.h:172 [inline] do_nanosleep+0x21f/0x640 kernel/time/hrtimer.c:1874 hrtimer_nanosleep+0x297/0x550 kernel/time/hrtimer.c:1927 __do_sys_nanosleep kernel/time/hrtimer.c:1961 [inline] __se_sys_nanosleep kernel/time/hrtimer.c:1948 [inline] __x64_sys_nanosleep+0x1a6/0x220 kernel/time/hrtimer.c:1948 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x441350 Code: c0 5b 5d c3 66 0f 1f 44 00 00 8b 04 24 48 83 c4 18 5b 5d c3 66 0f 1f 44 00 00 83 3d 01 b1 29 00 00 75 14 b8 23 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 74 21 fc ff c3 48 83 ec 08 e8 4a 44 00 00 RSP: 002b:00007ffec599b478 EFLAGS: 00000246 ORIG_RAX: 0000000000000023 RAX: ffffffffffffffda RBX: 00000000001939ee RCX: 0000000000441350 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007ffec599b480 RBP: 000000000000181f R08: 0000000000000001 R09: 000000000224d940 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000181d R13: 00007ffec599b680 R14: 0000000000000004 R15: 0000000000000000