INFO: task kworker/0:4:3693 blocked for more than 143 seconds. Not tainted 6.0.0-rc4-syzkaller-00204-g9b4509495418 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:4 state:D stack:23176 pid: 3693 ppid: 2 flags:0x00004000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:5182 [inline] __schedule+0xadf/0x52b0 kernel/sched/core.c:6494 schedule+0xda/0x1b0 kernel/sched/core.c:6570 scsi_remove_host+0x348/0x440 drivers/scsi/hosts.c:199 quiesce_and_remove_host drivers/usb/storage/usb.c:867 [inline] usb_stor_disconnect+0x115/0x260 drivers/usb/storage/usb.c:1087 usb_unbind_interface+0x1d8/0x8e0 drivers/usb/core/driver.c:458 device_remove drivers/base/dd.c:550 [inline] device_remove+0x11f/0x170 drivers/base/dd.c:542 __device_release_driver drivers/base/dd.c:1249 [inline] device_release_driver_internal+0x4a1/0x700 drivers/base/dd.c:1275 bus_remove_device+0x2e3/0x590 drivers/base/bus.c:529 device_del+0x4f3/0xc80 drivers/base/core.c:3704 usb_disable_device+0x356/0x7a0 drivers/usb/core/message.c:1419 usb_disconnect.cold+0x259/0x6ed drivers/usb/core/hub.c:2235 hub_port_connect drivers/usb/core/hub.c:5197 [inline] hub_port_connect_change drivers/usb/core/hub.c:5497 [inline] port_event drivers/usb/core/hub.c:5653 [inline] hub_event+0x1f86/0x4610 drivers/usb/core/hub.c:5735 process_one_work+0x991/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8bf888b0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x26/0xc70 kernel/rcu/tasks.h:507 1 lock held by rcu_tasks_trace/13: #0: ffffffff8bf885b0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x26/0xc70 kernel/rcu/tasks.h:507 1 lock held by khungtaskd/28: #0: ffffffff8bf89400 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6492 2 locks held by getty/3285: #0: ffff8880264cb098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:244 #1: ffffc90002d232f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xef0/0x13e0 drivers/tty/n_tty.c:2177 1 lock held by syz-executor.4/3663: 5 locks held by kworker/0:4/3693: #0: ffff88823bc16138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff88823bc16138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff88823bc16138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1280 [inline] #0: ffff88823bc16138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:636 [inline] #0: ffff88823bc16138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:663 [inline] #0: ffff88823bc16138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x87a/0x1610 kernel/workqueue.c:2260 #1: ffffc9000509fda8 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x8ae/0x1610 kernel/workqueue.c:2264 #2: ffff888021a97190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:835 [inline] #2: ffff888021a97190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1bc/0x4610 drivers/usb/core/hub.c:5681 #3: ffff8880770f5190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:835 [inline] #3: ffff8880770f5190 (&dev->mutex){....}-{3:3}, at: usb_disconnect.cold+0x43/0x6ed drivers/usb/core/hub.c:2226 #4: ffff8880770f1118 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:835 [inline] #4: ffff8880770f1118 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1073 [inline] #4: ffff8880770f1118 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xa0/0x700 drivers/base/dd.c:1272 2 locks held by kworker/0:6/3695: #0: ffff888011866538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888011866538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff888011866538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1280 [inline] #0: ffff888011866538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:636 [inline] #0: ffff888011866538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:663 [inline] #0: ffff888011866538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x87a/0x1610 kernel/workqueue.c:2260 #1: ffffc900050bfda8 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x8ae/0x1610 kernel/workqueue.c:2264 3 locks held by udevd/1179: #0: ffff88807e83d488 (&of->mutex){+.+.}-{3:3}, at: kernfs_file_read_iter fs/kernfs/file.c:253 [inline] #0: ffff88807e83d488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_read_iter+0x189/0x710 fs/kernfs/file.c:300 #1: ffff88801c6511d8 (kn->active#85){++++}-{0:0}, at: kernfs_file_read_iter fs/kernfs/file.c:254 [inline] #1: ffff88801c6511d8 (kn->active#85){++++}-{0:0}, at: kernfs_fop_read_iter+0x1ac/0x710 fs/kernfs/file.c:300 #2: ffff8880770f5190 (&dev->mutex){....}-{3:3}, at: device_lock_interruptible include/linux/device.h:840 [inline] #2: ffff8880770f5190 (&dev->mutex){....}-{3:3}, at: read_descriptors+0x3c/0x2c0 drivers/usb/core/sysfs.c:873 3 locks held by kworker/u4:2/1240: 1 lock held by kvm-nx-lpage-re/2050: #0: ffffffff8bfcf768 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_attach_task_all+0x21/0x150 kernel/cgroup/cgroup-v1.c:61 5 locks held by kvm-nx-lpage-re/2066: #0: ffffffff8bfcf768 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_attach_task_all+0x21/0x150 kernel/cgroup/cgroup-v1.c:61 #1: ffffffff8be365b0 (cpu_hotplug_lock){++++}-{0:0}, at: cgroup_attach_task_all+0x26/0x150 kernel/cgroup/cgroup-v1.c:62 #2: ffffffff8bfcf530 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_attach_task_all+0x32/0x150 kernel/cgroup/cgroup-v1.c:63 #3: ffffffff8bfddbf0 (&cpuset_rwsem){++++}-{0:0}, at: cpuset_can_attach+0xe8/0x440 kernel/cgroup/cpuset.c:2233 #4: ffffffff8bf940b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline] #4: ffffffff8bf940b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x562/0x670 kernel/rcu/tree_exp.h:940 1 lock held by syz-executor.3/2075: #0: ffffffff8bf93f80 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x44/0x720 kernel/rcu/tree.c:3788 1 lock held by syz-executor.1/2082: #0: ffffffff8bfcf530 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x50d/0x29b0 kernel/exit.c:751 1 lock held by syz-executor.1/2083: #0: ffffffff8bfcf530 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x50d/0x29b0 kernel/exit.c:751 1 lock held by syz-executor.1/2089: #0: ffffffff8bfcf530 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x50d/0x29b0 kernel/exit.c:751 1 lock held by syz-executor.1/2093: #0: ffffffff8bfcf530 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x50d/0x29b0 kernel/exit.c:751 1 lock held by syz-executor.0/2084: #0: ffffffff8bfcf530 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x50d/0x29b0 kernel/exit.c:751 1 lock held by syz-executor.0/2092: #0: ffffffff8bfcf530 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x50d/0x29b0 kernel/exit.c:751 1 lock held by kvm-nx-lpage-re/2091: #0: ffffffff8bfcf768 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_attach_task_all+0x21/0x150 kernel/cgroup/cgroup-v1.c:61 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 28 Comm: khungtaskd Not tainted 6.0.0-rc4-syzkaller-00204-g9b4509495418 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x46/0x14f lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x206/0x250 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] watchdog+0xc18/0xf50 kernel/hung_task.c:369 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 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:51 [inline] NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt+0x6f/0xb0 drivers/acpi/processor_idle.c:112