INFO: task systemd-shutdow:1 blocked for more than 143 seconds.
Not tainted 5.8.0-rc1-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
systemd-shutdow D24400 1 0 0x00004000
Call Trace:
context_switch kernel/sched/core.c:3430 [inline]
__schedule+0x8a1/0x1db0 kernel/sched/core.c:4155
schedule+0xcd/0x2b0 kernel/sched/core.c:4230
wait_for_device_probe+0x1be/0x220 drivers/base/dd.c:665
device_shutdown+0x18/0x5b5 drivers/base/core.c:3748
kernel_restart+0x11/0x30 kernel/reboot.c:246
__do_sys_reboot+0x31e/0x3e0 kernel/reboot.c:347
do_syscall_64+0x50/0x90 arch/x86/entry/common.c:359
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7fa94e4398c6
Code: Bad RIP value.
RSP: 002b:00007ffdd73d10c8 EFLAGS: 00000202 ORIG_RAX: 00000000000000a9
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fa94e4398c6
RDX: 0000000001234567 RSI: 0000000028121969 RDI: fffffffffee1dead
RBP: 00007ffdd73d1158 R08: 0000000000000028 R09: 0000000000000005
R10: 0000000000000002 R11: 0000000000000202 R12: 0000000000000000
R13: 0000000000000000 R14: 000056490f588150 R15: 00007ffdd73d1448
Showing all locks held in the system:
1 lock held by systemd-shutdow/1:
#0: ffffffff870e6528 (system_transition_mutex){+.+.}-{3:3}, at: __do_sys_reboot+0x1a3/0x3e0 kernel/reboot.c:344
1 lock held by khungtaskd/23:
#0: ffffffff8710fa20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x264 kernel/locking/lockdep.c:5779
5 locks held by kworker/1:3/3062:
#0: ffff8881d880ed38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: ffff8881d880ed38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline]
#0: ffff8881d880ed38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline]
#0: ffff8881d880ed38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline]
#0: ffff8881d880ed38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline]
#0: ffff8881d880ed38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x844/0x1620 kernel/workqueue.c:2240
#1: ffff8881d021fdc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x878/0x1620 kernel/workqueue.c:2244
#2: ffff8881d4415218 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:768 [inline]
#2: ffff8881d4415218 (&dev->mutex){....}-{3:3}, at: hub_event+0x1be/0x43c0 drivers/usb/core/hub.c:5522
#3: ffff8881ca59d218 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:768 [inline]
#3: ffff8881ca59d218 (&dev->mutex){....}-{3:3}, at: __device_attach+0x7b/0x390 drivers/base/dd.c:850
#4: ffff8881c3f151a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:768 [inline]
#4: ffff8881c3f151a8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x7b/0x390 drivers/base/dd.c:850
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 23 Comm: khungtaskd Not tainted 5.8.0-rc1-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+0xf6/0x16e lib/dump_stack.c:118
nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101
nmi_trigger_cpumask_backtrace+0x190/0x1aa 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+0xcfe/0xff0 kernel/hung_task.c:295
kthread+0x352/0x460 kernel/kthread.c:291
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:60 [inline]
NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:103 [inline]
NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt drivers/acpi/processor_idle.c:111 [inline]
NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt+0x72/0x90 drivers/acpi/processor_idle.c:108