INFO: task syz-executor.0:16117 can't die for more than 143 seconds. syz-executor.0 D29496 16117 8956 0x00004004 Call Trace: context_switch kernel/sched/core.c:3385 [inline] __schedule+0x94a/0x1e70 kernel/sched/core.c:4070 schedule+0xdc/0x2b0 kernel/sched/core.c:4144 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+0x247/0x470 fs/io-wq.c:922 io_finish_async+0x102/0x180 fs/io_uring.c:3211 io_ring_ctx_free fs/io_uring.c:3992 [inline] io_ring_ctx_wait_and_kill+0x24f/0x700 fs/io_uring.c:4060 io_uring_release+0x42/0x50 fs/io_uring.c:4068 __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: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+0x65f/0x760 arch/x86/entry/common.c:300 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45a219 Code: Bad RIP value. RSP: 002b:00007f46f5ec6c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000001 RCX: 000000000045a219 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f46f5ec76d4 R13: 00000000004faf72 R14: 00000000004d3238 R15: 00000000ffffffff INFO: task syz-executor.0:16117 blocked for more than 143 seconds. Not tainted 5.4.0-rc6-next-20191108 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D29496 16117 8956 0x00004004 Call Trace: context_switch kernel/sched/core.c:3385 [inline] __schedule+0x94a/0x1e70 kernel/sched/core.c:4070 schedule+0xdc/0x2b0 kernel/sched/core.c:4144 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+0x247/0x470 fs/io-wq.c:922 io_finish_async+0x102/0x180 fs/io_uring.c:3211 io_ring_ctx_free fs/io_uring.c:3992 [inline] io_ring_ctx_wait_and_kill+0x24f/0x700 fs/io_uring.c:4060 io_uring_release+0x42/0x50 fs/io_uring.c:4068 __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: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+0x65f/0x760 arch/x86/entry/common.c:300 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45a219 Code: Bad RIP value. RSP: 002b:00007f46f5ec6c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000001 RCX: 000000000045a219 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f46f5ec76d4 R13: 00000000004faf72 R14: 00000000004d3238 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/946: #0: ffffffff88fab880 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x279 kernel/locking/lockdep.c:5336 1 lock held by rsyslogd/8828: #0: ffff8880989a3de0 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 2 locks held by getty/8918: #0: ffff888098070090 (&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/8919: #0: ffff88809a7e0090 (&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/8920: #0: ffff8880a0646090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f4b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/8921: #0: ffff888094435090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f432e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/8922: #0: ffff8880a52a2090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f2d2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/8923: #0: ffff8880a7bbc090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f472e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/8924: #0: ffff8880a3831090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f192e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 946 Comm: khungtaskd Not tainted 5.4.0-rc6-next-20191108 #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: 0 Comm: swapper/0 Not tainted 5.4.0-rc6-next-20191108 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__sanitizer_cov_trace_cmp8+0xf/0x20 kernel/kcov.c:254 Code: bf 04 00 00 00 48 89 e5 48 8b 4d 08 e8 3a ff ff ff 5d c3 0f 1f 84 00 00 00 00 00 55 48 89 f2 48 89 fe bf 06 00 00 00 48 89 e5 <48> 8b 4d 08 e8 18 ff ff ff 5d c3 66 0f 1f 44 00 00 55 40 0f b6 d6 RSP: 0018:ffff8880ae809938 EFLAGS: 00000006 RAX: ffffffff88e7a1c0 RBX: 0000000000000002 RCX: ffffffff87519340 RDX: 0000000000000002 RSI: 0000000000000040 RDI: 0000000000000006 RBP: ffff8880ae809938 R08: ffffffff88e7a1c0 R09: ffffed101533e91f R10: ffffed101533e91e R11: ffff8880a99f48f7 R12: 0000000000000002 R13: 0000000000000040 R14: 0000000000000000 R15: ffff8880a9813118 FS: 0000000000000000(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 000000009421e000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: _find_next_bit lib/find_bit.c:36 [inline] find_next_bit+0x26/0x130 lib/find_bit.c:70 cpumask_next+0x41/0x50 lib/cpumask.c:22 cpumask_next_wrap+0x28/0xa0 lib/cpumask.c:82 select_idle_cpu kernel/sched/fair.c:5831 [inline] select_idle_sibling kernel/sched/fair.c:5891 [inline] select_idle_sibling+0x6f2/0xfd0 kernel/sched/fair.c:5853 select_task_rq_fair+0xc6f/0x1810 kernel/sched/fair.c:6360 select_task_rq kernel/sched/core.c:2109 [inline] try_to_wake_up+0x435/0x1ab0 kernel/sched/core.c:2628 wake_up_process+0x10/0x20 kernel/sched/core.c:2668 wake_up_worker kernel/workqueue.c:835 [inline] insert_work+0x2b8/0x3b0 kernel/workqueue.c:1336 __queue_work+0x540/0x1280 kernel/workqueue.c:1485 delayed_work_timer_fn+0x5d/0x90 kernel/workqueue.c:1610 call_timer_fn+0x1ac/0x780 kernel/time/timer.c:1404 expire_timers kernel/time/timer.c:1444 [inline] __run_timers kernel/time/timer.c:1773 [inline] __run_timers kernel/time/timer.c:1740 [inline] run_timer_softirq+0x48c/0x1790 kernel/time/timer.c:1786 __do_softirq+0x262/0x98c kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x19b/0x1e0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0x1a3/0x610 arch/x86/kernel/apic/apic.c:1137 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829 RIP: 0010:native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:61 Code: 28 4a 57 fa eb 8a 90 90 90 90 90 90 e9 07 00 00 00 0f 00 2d 74 13 50 00 f4 c3 66 90 e9 07 00 00 00 0f 00 2d 64 13 50 00 fb f4 90 55 48 89 e5 41 57 41 56 41 55 41 54 53 e8 2e e0 08 fa e8 d9 RSP: 0018:ffffffff88e07ce8 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 RAX: 1ffffffff11e640f RBX: ffffffff88e7a1c0 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: 0000000000000006 RDI: ffffffff88e7aa5c RBP: ffffffff88e07d18 R08: ffffffff88e7a1c0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000 R13: ffffffff89c812c0 R14: 0000000000000000 R15: 0000000000000000 arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:571 default_idle_call+0x84/0xb0 kernel/sched/idle.c:94 cpuidle_idle_call kernel/sched/idle.c:154 [inline] do_idle+0x3b7/0x6e0 kernel/sched/idle.c:263 cpu_startup_entry+0x1b/0x20 kernel/sched/idle.c:355 rest_init+0x23b/0x371 init/main.c:451 arch_call_rest_init+0xe/0x1b start_kernel+0x904/0x943 init/main.c:784 x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:490 x86_64_start_kernel+0x77/0x7b arch/x86/kernel/head64.c:471 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:242