INFO: task systemd-shutdow:1 blocked for more than 143 seconds. Not tainted 5.12.0-rc7-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:systemd-shutdow state:D stack:22688 pid: 1 ppid: 0 flags:0x00000000 Call Trace: context_switch kernel/sched/core.c:4322 [inline] __schedule+0x920/0x1fa0 kernel/sched/core.c:5073 schedule+0xcb/0x270 kernel/sched/core.c:5152 wait_for_device_probe+0x1be/0x220 drivers/base/dd.c:709 device_shutdown+0x18/0x5c0 drivers/base/core.c:4313 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/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f9b1b9ec8c6 RSP: 002b:00007ffd1ef62ca8 EFLAGS: 00000202 ORIG_RAX: 00000000000000a9 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f9b1b9ec8c6 RDX: 0000000001234567 RSI: 0000000028121969 RDI: fffffffffee1dead RBP: 00007ffd1ef62d38 R08: 0000000000002800 R09: 0000000000000005 R10: 0000000000000002 R11: 0000000000000202 R12: 0000000000000000 R13: 0000000000000000 R14: 000055c7bf1e1150 R15: 00007ffd1ef63028 Showing all locks held in the system: 1 lock held by systemd-shutdow/1: #0: ffffffff87952f08 (system_transition_mutex){+.+.}-{3:3}, at: __do_sys_reboot+0x1a4/0x3e0 kernel/reboot.c:344 1 lock held by khungtaskd/1274: #0: ffffffff87a78a20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x269 kernel/locking/lockdep.c:6328 5 locks held by kworker/1:8/18688: #0: ffff888103e2bd38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888103e2bd38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff888103e2bd38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff888103e2bd38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff888103e2bd38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff888103e2bd38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x871/0x1580 kernel/workqueue.c:2246 #1: ffffc90011ab7da8 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x8a5/0x1580 kernel/workqueue.c:2250 #2: ffff888109223220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:740 [inline] #2: ffff888109223220 (&dev->mutex){....}-{3:3}, at: hub_event+0x1c1/0x4320 drivers/usb/core/hub.c:5590 #3: ffff88810bf5e220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:740 [inline] #3: ffff88810bf5e220 (&dev->mutex){....}-{3:3}, at: __device_attach+0x7a/0x4a0 drivers/base/dd.c:894 #4: ffff88810bf5f1a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:740 [inline] #4: ffff88810bf5f1a8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x7a/0x4a0 drivers/base/dd.c:894 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1274 Comm: khungtaskd Not tainted 5.12.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x143/0x1db lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x46/0xe0 lib/nmi_backtrace.c:105 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+0xd32/0xf70 kernel/hung_task.c:294 kthread+0x38c/0x460 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.12.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:rcu_irq_enter+0x0/0x30 kernel/rcu/tree.c:1118 Code: 00 00 e8 b3 fc ff ff e8 3e 5c bd fb be 04 00 00 00 4c 89 e7 e8 41 5c bd fb eb b4 bd 02 00 00 00 eb ad 0f 0b e9 75 ff ff ff 90 <8b> 05 c6 b0 1c 03 85 c0 74 18 65 8b 05 77 93 51 7a 85 c0 75 0d 65 RSP: 0018:ffffc900000dfc40 EFLAGS: 00000002 RAX: ffff8881002d0000 RBX: 0000000000000000 RCX: 000000000173b4cb RDX: 000000000173b4cc RSI: ffffffff85c00c9a RDI: ffffffff85b0560b RBP: ffffc900000dfc68 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881f6b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffd1ef61d2c CR3: 0000000103225000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: irqentry_enter+0x38/0x50 kernel/entry/common.c:360 sysvec_call_function_single+0xb/0x90 arch/x86/kernel/smp.c:243 asm_sysvec_call_function_single+0x12/0x20 arch/x86/include/asm/idtentry.h:640 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:70 [inline] RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:137 [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: 6d 98 8e fb 84 db 75 ac e8 c4 91 8e fb e8 3f 69 94 fb e9 0c 00 00 00 e8 b5 91 8e fb 0f 00 2d 1e a8 76 00 e8 a9 91 8e fb fb f4 <9c> 5b 81 e3 00 02 00 00 fa 31 ff 48 89 de e8 a4 99 8e fb 48 85 db RSP: 0018:ffffc900000dfd18 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff8881002d0000 RSI: ffffffff85b1d067 RDI: ffffffff85b1d051 RBP: ffff88810216f864 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff814639c8 R11: 0000000000000000 R12: 0000000000000001 R13: ffff88810216f800 R14: ffff88810216f864 R15: ffff8881057c4004 acpi_idle_enter+0x355/0x4f0 drivers/acpi/processor_idle.c:652 cpuidle_enter_state+0x1b1/0xc80 drivers/cpuidle/cpuidle.c:237 cpuidle_enter+0x4a/0xa0 drivers/cpuidle/cpuidle.c:351 call_cpuidle kernel/sched/idle.c:158 [inline] cpuidle_idle_call kernel/sched/idle.c:239 [inline] do_idle+0x3d5/0x580 kernel/sched/idle.c:300 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:397 start_secondary+0x273/0x350 arch/x86/kernel/smpboot.c:272 secondary_startup_64_no_verify+0xb0/0xbb