INFO: task systemd-shutdow:1 blocked for more than 143 seconds. Not tainted 5.12.0-rc1-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:systemd-shutdow state:D stack:22672 pid: 1 ppid: 0 flags:0x00000000 Call Trace: context_switch kernel/sched/core.c:4324 [inline] __schedule+0x91b/0x1f90 kernel/sched/core.c:5075 schedule+0xcb/0x270 kernel/sched/core.c:5154 wait_for_device_probe+0x1be/0x220 drivers/base/dd.c:704 device_shutdown+0x18/0x5c0 drivers/base/core.c:4313 kernel_restart_prepare kernel/reboot.c:76 [inline] kernel_restart+0x61/0xa0 kernel/reboot.c:246 __do_sys_reboot+0x31e/0x3e0 kernel/reboot.c:349 do_syscall_64+0x2d/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fc53db788c6 RSP: 002b:00007ffe68e30378 EFLAGS: 00000206 ORIG_RAX: 00000000000000a9 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fc53db788c6 RDX: 0000000001234567 RSI: 0000000028121969 RDI: fffffffffee1dead RBP: 00007ffe68e30408 R08: 0000000000002800 R09: 0000000000000005 R10: 0000000000000002 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 00005648ba8aa150 R15: 00007ffe68e306f8 Showing all locks held in the system: 1 lock held by systemd-shutdow/1: #0: ffffffff87952b28 (system_transition_mutex){+.+.}-{3:3}, at: __do_sys_reboot+0x1a3/0x3e0 kernel/reboot.c:346 1 lock held by khungtaskd/1273: #0: ffffffff87a781e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x269 kernel/locking/lockdep.c:6327 6 locks held by kworker/0:4/7241: #0: ffff888103f34538 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888103f34538 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff888103f34538 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff888103f34538 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff888103f34538 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff888103f34538 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x871/0x1580 kernel/workqueue.c:2246 #1: ffffc900059ffda8 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x8a5/0x1580 kernel/workqueue.c:2250 #2: ffff888108f89218 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:740 [inline] #2: ffff888108f89218 (&dev->mutex){....}-{3:3}, at: hub_event+0x1c1/0x4320 drivers/usb/core/hub.c:5537 #3: ffff88810f0b9218 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:740 [inline] ffff88810f0b9218 (&dev->mutex){....}-{3:3}, at: __device_attach+0x7a/0x4a0 drivers/base/dd.c:889 #4: ffff888103e3f1a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:740 [inline] #4: ffff888103e3f1a8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x7a/0x4a0 drivers/base/dd.c:889 #5: ffff88810d178c60 (&dev->phy_mutex){+.+.}-{3:3}, at: asix_mdio_read+0x9a/0x320 drivers/net/usb/asix_common.c:452 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1273 Comm: khungtaskd Not tainted 5.12.0-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:79 [inline] dump_stack+0xfa/0x151 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 7241 Comm: kworker/0:4 Not tainted 5.12.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: usb_hub_wq hub_event RIP: 0010:desc_read+0x195/0x350 kernel/printk/printk_ringbuffer.c:480 Code: fa 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 a7 01 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 14 24 4d 8b 2f <48> c1 ea 03 80 3c 02 00 0f 85 95 01 00 00 48 8b 04 24 4c 89 28 e8 RSP: 0018:ffffc900059fe7e0 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: ffffffff87a467e8 RCX: ffffc90010a61000 RDX: ffffc900059fe850 RSI: ffffffff81296ce9 RDI: ffffc900059fe9b0 RBP: ffffc900059fe998 R08: 0000000000000001 R09: ffffc900059fe9af R10: fffff52000b3fd35 R11: 0000000000000001 R12: 0000000100014957 R13: 0000000000016957 R14: 0000000000000002 R15: ffffffff879bbd88 FS: 0000000000000000(0000) GS:ffff8881f6a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffe68e2fa28 CR3: 0000000100f9d000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: desc_read_finalized_seq+0x81/0x1c0 kernel/printk/printk_ringbuffer.c:1752 prb_read kernel/printk/printk_ringbuffer.c:1800 [inline] _prb_read_valid+0x1cd/0x710 kernel/printk/printk_ringbuffer.c:1880 prb_read_valid+0x75/0xa0 kernel/printk/printk_ringbuffer.c:1929 console_unlock+0x20d/0xb70 kernel/printk/printk.c:2523 vprintk_emit+0x1f1/0x480 kernel/printk/printk.c:2098 dev_vprintk_emit+0x36e/0x3b2 drivers/base/core.c:4434 dev_printk_emit+0xba/0xf1 drivers/base/core.c:4445 __netdev_printk+0x1c6/0x27a net/core/dev.c:11262 netdev_err+0xd7/0x109 net/core/dev.c:11314 asix_set_sw_mii drivers/net/usb/asix_common.c:278 [inline] asix_set_sw_mii drivers/net/usb/asix_common.c:272 [inline] asix_mdio_read.cold+0x61/0xa5 drivers/net/usb/asix_common.c:454 asix_phy_reset+0x104/0x170 drivers/net/usb/asix_devices.c:215 ax88172_bind+0x412/0x5d0 drivers/net/usb/asix_devices.c:272 usbnet_probe+0xb25/0x2740 drivers/net/usb/usbnet.c:1702 usb_probe_interface+0x315/0x7f0 drivers/usb/core/driver.c:396 really_probe+0x291/0xe60 drivers/base/dd.c:554 driver_probe_device+0x26b/0x3d0 drivers/base/dd.c:740 __device_attach_driver+0x1d1/0x290 drivers/base/dd.c:846 bus_for_each_drv+0x15f/0x1e0 drivers/base/bus.c:431 __device_attach+0x228/0x4a0 drivers/base/dd.c:914 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:491 device_add+0xbdb/0x1db0 drivers/base/core.c:3242 usb_set_configuration+0x113f/0x1910 drivers/usb/core/message.c:2164 usb_generic_driver_probe+0xba/0x100 drivers/usb/core/generic.c:238 usb_probe_device+0xd9/0x2c0 drivers/usb/core/driver.c:293 really_probe+0x291/0xe60 drivers/base/dd.c:554 driver_probe_device+0x26b/0x3d0 drivers/base/dd.c:740 __device_attach_driver+0x1d1/0x290 drivers/base/dd.c:846 bus_for_each_drv+0x15f/0x1e0 drivers/base/bus.c:431 __device_attach+0x228/0x4a0 drivers/base/dd.c:914 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:491 device_add+0xbdb/0x1db0 drivers/base/core.c:3242 usb_new_device.cold+0x721/0x1058 drivers/usb/core/hub.c:2555 hub_port_connect drivers/usb/core/hub.c:5223 [inline] hub_port_connect_change drivers/usb/core/hub.c:5363 [inline] port_event drivers/usb/core/hub.c:5509 [inline] hub_event+0x2357/0x4320 drivers/usb/core/hub.c:5591 process_one_work+0x98d/0x1580 kernel/workqueue.c:2275 process_scheduled_works kernel/workqueue.c:2337 [inline] worker_thread+0x82b/0x1120 kernel/workqueue.c:2423 kthread+0x38c/0x460 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294