INFO: task systemd-shutdow:1 blocked for more than 143 seconds. Not tainted 5.9.0-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:systemd-shutdow state:D stack:24512 pid: 1 ppid: 0 flags:0x00000000 Call Trace: context_switch kernel/sched/core.c:3774 [inline] __schedule+0x88f/0x1f00 kernel/sched/core.c:4523 schedule+0xcb/0x270 kernel/sched/core.c:4601 wait_for_device_probe+0x1be/0x220 drivers/base/dd.c:702 device_shutdown+0x18/0x5c0 drivers/base/core.c:4007 kernel_restart_prepare kernel/reboot.c:76 [inline] kernel_restart kernel/reboot.c:246 [inline] __do_sys_reboot.cold+0x5d/0x97 kernel/reboot.c:347 do_syscall_64+0x2d/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7fcf7f6e58c6 Code: Unable to access opcode bytes at RIP 0x7fcf7f6e589c. RSP: 002b:00007fff02655a48 EFLAGS: 00000206 ORIG_RAX: 00000000000000a9 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fcf7f6e58c6 RDX: 0000000001234567 RSI: 0000000028121969 RDI: fffffffffee1dead RBP: 00007fff02655ad8 R08: 0000000000005001 R09: 0000000000000005 R10: 0000000000000002 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 00005581dd161150 R15: 00007fff02655dc8 Showing all locks held in the system: 1 lock held by systemd-shutdow/1: #0: ffffffff872f0968 (system_transition_mutex){+.+.}-{3:3}, at: __do_sys_reboot+0x1a4/0x3e0 kernel/reboot.c:344 1 lock held by khungtaskd/23: #0: ffffffff873fc3a0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x264 kernel/locking/lockdep.c:6259 5 locks held by kworker/0:4/3104: #0: ffff8881d887d938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8881d887d938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff8881d887d938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff8881d887d938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff8881d887d938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff8881d887d938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x821/0x1520 kernel/workqueue.c:2240 #1: ffff8881cb38fda8 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x854/0x1520 kernel/workqueue.c:2244 #2: ffff8881d449d218 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:731 [inline] #2: ffff8881d449d218 (&dev->mutex){....}-{3:3}, at: hub_event+0x1c5/0x42b0 drivers/usb/core/hub.c:5536 #3: ffff8881d229d218 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:731 [inline] #3: ffff8881d229d218 (&dev->mutex){....}-{3:3}, at: __device_attach+0x7a/0x4a0 drivers/base/dd.c:887 #4: ffff8881d48f81a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:731 [inline] #4: ffff8881d48f81a8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x7a/0x4a0 drivers/base/dd.c:887 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 23 Comm: khungtaskd Not tainted 5.9.0-syzkaller #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+0x107/0x163 lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x74/0xb6 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1da/0x200 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:209 [inline] watchdog+0xd28/0xf70 kernel/hung_task.c:295 kthread+0x392/0x470 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.9.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:asm_sysvec_call_function_single+0x0/0x20 arch/x86/include/asm/idtentry.h:638 Code: 00 66 0f 1f 84 00 00 00 00 00 0f 1f 00 6a ff e8 56 03 00 00 48 89 e7 e8 be c0 f9 ff e9 09 04 00 00 66 0f 1f 84 00 00 00 00 00 <0f> 1f 00 6a ff e8 36 03 00 00 48 89 e7 e8 6e c2 f9 ff e9 e9 03 00 RSP: 0018:ffffffff87207d38 EFLAGS: 00000093 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 1ffffffff103af21 RDX: ffffffff872304c0 RSI: ffffffff85bb48e7 RDI: ffffffff85bb48d1 RBP: ffff8881d8d32064 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000001 R13: ffff8881d8d32000 R14: ffff8881d8d32064 R15: ffff8881d769f804 FS: 0000000000000000(0000) GS:ffff8881db200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fff02654f78 CR3: 00000001c9674000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:29 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:79 [inline] RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:169 [inline] RIP: 0010:acpi_safe_halt drivers/acpi/processor_idle.c:112 [inline] RIP: 0010:acpi_idle_do_entry+0x1c9/0x250 drivers/acpi/processor_idle.c:517 Code: 4d ce 83 fb 84 db 75 ac e8 d4 d5 83 fb e8 ff 69 89 fb e9 0c 00 00 00 e8 c5 d5 83 fb 0f 00 2d 9e ac 69 00 e8 b9 d5 83 fb fb f4 <9c> 5b 81 e3 00 02 00 00 fa 31 ff 48 89 de e8 74 ce 83 fb 48 85 db RSP: 0018:ffffffff87207d60 EFLAGS: 00000293 acpi_idle_enter+0x337/0x490 drivers/acpi/processor_idle.c:648 cpuidle_enter_state+0x1a2/0xa80 drivers/cpuidle/cpuidle.c:237 cpuidle_enter+0x4a/0xa0 drivers/cpuidle/cpuidle.c:351 call_cpuidle kernel/sched/idle.c:132 [inline] cpuidle_idle_call kernel/sched/idle.c:213 [inline] do_idle+0x3d5/0x580 kernel/sched/idle.c:273 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:369 start_kernel+0x495/0x4b6 init/main.c:1049 secondary_startup_64_no_verify+0xb8/0xbb