INFO: task syz-executor.0:27417 can't die for more than 143 seconds. syz-executor.0 D28160 27417 8996 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+0x131/0x720 kernel/kthread.c:559 io_sq_thread_stop fs/io_uring.c:2468 [inline] io_finish_async+0x73/0x140 fs/io_uring.c:2475 io_ring_ctx_free fs/io_uring.c:2986 [inline] io_ring_ctx_wait_and_kill+0x133/0x600 fs/io_uring.c:3050 io_uring_release+0x42/0x50 fs/io_uring.c:3058 __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+0x280/0x2d0 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: 0033:0x413201 Code: 48 89 54 24 10 48 85 d2 0f 86 cd 00 00 00 48 89 d3 31 d2 48 f7 f3 48 c7 41 30 00 00 00 00 48 c7 41 40 ff ff ff ff 48 89 41 38 <48> c7 41 48 00 00 00 00 48 c7 41 50 00 00 00 00 48 8b 41 38 48 89 RSP: 002b:00007fffeb10bae0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000005 RCX: 0000000000413201 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 0000000000000001 R08: ffffffff8177dec6 R09: 0000000085689200 R10: 00007fffeb10bbc0 R11: 0000000000000293 R12: 0000000000760e58 R13: 00000000000d6a10 R14: 00000000000d6a3d R15: ffffffffffffffff INFO: task syz-executor.0:27417 blocked for more than 143 seconds. Not tainted 5.2.0-rc6-next-20190628 #25 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D28160 27417 8996 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+0x131/0x720 kernel/kthread.c:559 io_sq_thread_stop fs/io_uring.c:2468 [inline] io_finish_async+0x73/0x140 fs/io_uring.c:2475 io_ring_ctx_free fs/io_uring.c:2986 [inline] io_ring_ctx_wait_and_kill+0x133/0x600 fs/io_uring.c:3050 io_uring_release+0x42/0x50 fs/io_uring.c:3058 __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+0x280/0x2d0 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: 0033:0x413201 Code: 48 89 54 24 10 48 85 d2 0f 86 cd 00 00 00 48 89 d3 31 d2 48 f7 f3 48 c7 41 30 00 00 00 00 48 c7 41 40 ff ff ff ff 48 89 41 38 <48> c7 41 48 00 00 00 00 48 c7 41 50 00 00 00 00 48 8b 41 38 48 89 RSP: 002b:00007fffeb10bae0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000005 RCX: 0000000000413201 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 0000000000000001 R08: ffffffff8177dec6 R09: 0000000085689200 R10: 00007fffeb10bbc0 R11: 0000000000000293 R12: 0000000000760e58 R13: 00000000000d6a10 R14: 00000000000d6a3d R15: ffffffffffffffff Showing all locks held in the system: 1 lock held by khungtaskd/1046: #0: 0000000041501c07 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:5257 1 lock held by rsyslogd/8867: 2 locks held by getty/8957: #0: 0000000018ef0315 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000018fad2cb (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/8958: #0: 000000001237f286 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000f50588e5 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/8959: #0: 0000000068bc6903 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000976567d2 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/8960: #0: 00000000d07eea15 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000054633e6f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/8961: #0: 00000000d03e0c56 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000035aa00fe (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/8962: #0: 0000000013db61ad (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000da2b527c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/8963: #0: 0000000011296ee8 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000007dc3da70 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1046 Comm: khungtaskd Not tainted 5.2.0-rc6-next-20190628 #25 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:249 [inline] watchdog+0xc54/0x1320 kernel/hung_task.c:333 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:353 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.2.0-rc6-next-20190628 #25 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:reschedule_interrupt+0x0/0x20 arch/x86/entry/entry_64.S:831 Code: 66 2e 0f 1f 84 00 00 00 00 00 68 03 ff ff ff e8 e6 f1 ff ff e8 c1 23 00 00 e9 bb f2 ff ff 66 90 66 2e 0f 1f 84 00 00 00 00 00 <68> 02 ff ff ff e8 c6 f1 ff ff e8 e1 1e 00 00 e9 9b f2 ff ff 66 90 RSP: 0018:ffffffff88c07cb8 EFLAGS: 00000082 RAX: 1ffffffff11a5d49 RBX: ffffffff88c7a240 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: 0000000000000006 RDI: ffffffff88c7aad4 RBP: ffffffff88c07d18 R08: ffffffff88c7a240 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000 R13: ffffffff89a340f8 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 0000000094b1a000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: 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+0x413/0x760 kernel/sched/idle.c:263 cpu_startup_entry+0x1b/0x20 kernel/sched/idle.c:354 rest_init+0x245/0x37b init/main.c:451 arch_call_rest_init+0xe/0x1b start_kernel+0x8de/0x91d init/main.c:785 x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:470 x86_64_start_kernel+0x77/0x7b arch/x86/kernel/head64.c:451 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243