INFO: task kworker/1:3:273 blocked for more than 143 seconds. Not tainted 5.7.0-rc6-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/1:3 D23616 273 2 0x80004000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:3367 [inline] __schedule+0x892/0x1d80 kernel/sched/core.c:4083 lock_downgrade+0x720/0x720 kernel/locking/lockdep.c:4599 __sched_text_start+0x8/0x8 __trace_hardirqs_on_caller kernel/locking/lockdep.c:3657 [inline] lockdep_hardirqs_on+0x3c7/0x5d0 kernel/locking/lockdep.c:3702 schedule+0xcd/0x2b0 kernel/sched/core.c:4158 rwsem_down_write_slowpath+0x77f/0xf20 kernel/locking/rwsem.c:1235 print_usage_bug+0x200/0x200 kernel/locking/lockdep.c:101 rwsem_mark_wake+0x8d0/0x8d0 include/linux/compiler.h:199 lock_acquire+0x18b/0x7c0 kernel/locking/lockdep.c:4934 usb_deregister_dev+0xaa/0x300 drivers/usb/core/file.c:239 lock_release+0x720/0x720 kernel/locking/lockdep.c:4689 __down_write kernel/locking/rwsem.c:1389 [inline] down_write+0x13c/0x150 kernel/locking/rwsem.c:1532 atomic64_try_cmpxchg include/asm-generic/atomic-instrumented.h:1504 [inline] atomic_long_try_cmpxchg_acquire include/asm-generic/atomic-long.h:442 [inline] __down_write kernel/locking/rwsem.c:1387 [inline] down_write+0xb7/0x150 kernel/locking/rwsem.c:1532 __down_write kernel/locking/rwsem.c:1389 [inline] down_write+0x13c/0x150 kernel/locking/rwsem.c:1532 __down_timeout+0x2d0/0x2d0 usb_deregister_dev+0xaa/0x300 drivers/usb/core/file.c:239 sisusb_disconnect+0x5a/0x200 drivers/usb/misc/sisusbvga/sisusb.c:3166 usb_unbind_interface+0x1bd/0x8a0 drivers/usb/core/driver.c:436 __pm_runtime_idle+0xd1/0x310 drivers/base/power/runtime.c:1021 usb_autoresume_device+0x60/0x60 include/linux/pm_runtime.h:252 __device_release_driver drivers/base/dd.c:1110 [inline] device_release_driver_internal+0x432/0x500 drivers/base/dd.c:1141 bus_remove_device+0x2eb/0x5a0 drivers/base/bus.c:533 device_del+0x481/0xd30 drivers/base/core.c:2715 device_create_with_groups+0x120/0x120 drivers/base/core.c:3308 usb_remove_ep_devs+0x3e/0x80 drivers/usb/core/endpoint.c:215 remove_intf_ep_devs+0x13f/0x1d0 drivers/usb/core/message.c:1121 usb_disable_device+0x23d/0x790 drivers/usb/core/message.c:1245 usb_disconnect+0x293/0x900 drivers/usb/core/hub.c:2217 hub_port_connect drivers/usb/core/hub.c:5059 [inline] hub_port_connect_change drivers/usb/core/hub.c:5348 [inline] port_event drivers/usb/core/hub.c:5494 [inline] hub_event+0x1abf/0x43c0 drivers/usb/core/hub.c:5576 hub_port_debounce+0x350/0x350 drivers/usb/core/hub.c:4441 __x64_sys_sysinfo+0x30/0x40 kernel/sys.c:2604 lock_is_held include/linux/lockdep.h:406 [inline] rcu_read_lock_sched_held+0x9c/0xd0 kernel/rcu/update.c:121 rcu_read_lock_bh_held+0xb0/0xb0 kernel/rcu/update.c:333 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:168 [inline] _raw_spin_unlock_irq+0x1f/0x30 kernel/locking/spinlock.c:199 process_one_work+0x965/0x1630 kernel/workqueue.c:2268 lock_release+0x720/0x720 kernel/locking/lockdep.c:4689 pwq_dec_nr_in_flight+0x310/0x310 kernel/workqueue.c:1198 rwlock_bug.part.0+0x90/0x90 include/linux/sched.h:1332 process_scheduled_works kernel/workqueue.c:2330 [inline] worker_thread+0x7ab/0xe20 kernel/workqueue.c:2416 process_one_work+0x1630/0x1630 kernel/workqueue.c:1029 kthread+0x326/0x430 kernel/kthread.c:268 kthread_create_on_node+0xf0/0xf0 kernel/kthread.c:405 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:351 Showing all locks held in the system: 1 lock held by khungtaskd/23: #0: ffffffff87111260 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x264 kernel/locking/lockdep.c:5754 2 locks held by in:imklog/268: #0: ffff8881c9fc0370 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:826 #1: ffffffff8719fce0 (fs_reclaim){+.+.}-{0:0}, at: syslog_print kernel/printk/printk.c:1392 [inline] #1: ffffffff8719fce0 (fs_reclaim){+.+.}-{0:0}, at: do_syslog kernel/printk/printk.c:1557 [inline] #1: ffffffff8719fce0 (fs_reclaim){+.+.}-{0:0}, at: do_syslog+0x791/0x1380 kernel/printk/printk.c:1531 6 locks held by kworker/1:3/273: #0: ffff8881d8d90d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: __write_once_size include/linux/compiler.h:226 [inline] #0: ffff8881d8d90d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8881d8d90d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: ffff8881d8d90d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: ffff8881d8d90d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:615 [inline] #0: ffff8881d8d90d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:642 [inline] #0: ffff8881d8d90d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x844/0x1630 kernel/workqueue.c:2239 #1: ffff8881c9497dc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x878/0x1630 kernel/workqueue.c:2243 #2: ffff8881d4b32218 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:768 [inline] #2: ffff8881d4b32218 (&dev->mutex){....}-{3:3}, at: hub_event+0x1be/0x43c0 drivers/usb/core/hub.c:5522 #3: ffff8881d01e5218 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:768 [inline] #3: ffff8881d01e5218 (&dev->mutex){....}-{3:3}, at: usb_disconnect+0x91/0x900 drivers/usb/core/hub.c:2208 #4: ffff8881ab1ad1a8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0x23/0x500 drivers/base/dd.c:1138 #5: ffffffff876a5450 (minor_rwsem){++++}-{3:3}, at: usb_deregister_dev+0xaa/0x300 drivers/usb/core/file.c:239 2 locks held by syz-executor.5/9415: #0: ffffffff876a5450 (minor_rwsem){++++}-{3:3}, at: usb_open+0x23/0x270 drivers/usb/core/file.c:39 #1: ffff8881cf91c0d0 (&(sisusb->lock)){+.+.}-{3:3}, at: sisusb_open+0xb2/0x4d0 drivers/usb/misc/sisusbvga/sisusb.c:2396 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 23 Comm: khungtaskd Not tainted 5.7.0-rc6-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+0xef/0x16e lib/dump_stack.c:118 irq_force_complete_move.cold+0x13/0x47 arch/x86/kernel/apic/vector.c:1023 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101 lapic_can_unplug_cpu.cold+0x3b/0x3b nmi_trigger_cpumask_backtrace+0x1db/0x207 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xa99/0xfd0 kernel/hung_task.c:289 reset_hung_task_detector+0x30/0x30 kernel/hung_task.c:243 kthread+0x326/0x430 kernel/kthread.c:268 kthread_create_on_node+0xf0/0xf0 kernel/kthread.c:405 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:351 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 default_idle+0x28/0x300 arch/x86/kernel/process.c:697