Warning: Permanently added '10.128.0.251' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 45.275903][ T83] usb 1-1: new high-speed USB device number 2 using dummy_hcd [ 45.515846][ T83] usb 1-1: Using ep0 maxpacket: 8 [ 45.635979][ T83] usb 1-1: config 0 has an invalid interface number: 219 but max is 0 [ 45.644430][ T83] usb 1-1: config 0 has no interface number 0 [ 45.650657][ T83] usb 1-1: config 0 interface 219 altsetting 0 endpoint 0xF has an invalid bInterval 0, changing to 7 [ 45.661707][ T83] usb 1-1: config 0 interface 219 altsetting 0 endpoint 0x83 has an invalid bInterval 0, changing to 7 [ 45.673365][ T83] usb 1-1: New USB device found, idVendor=0694, idProduct=0001, bcdDevice=eb.88 [ 45.682515][ T83] usb 1-1: New USB device strings: Mfr=0, Product=0, SerialNumber=0 [ 45.692436][ T83] usb 1-1: config 0 descriptor?? [ 45.956369][ T83] legousbtower 1-1:0.219: LEGO USB Tower firmware version is 129.136 build 65535 [ 45.968456][ T83] legousbtower 1-1:0.219: LEGO USB Tower #-160 now attached to major 180 minor 0 [ 47.236010][ T1721] usb 1-1: LEGO USB Tower reset control request failed [ 47.243948][ T83] usb 1-1: USB disconnect, device number 2 [ 47.253627][ T83] [ 47.256061][ T83] ====================================================== [ 47.263218][ T83] WARNING: possible circular locking dependency detected [ 47.270212][ T83] 5.3.0+ #0 Not tainted [ 47.275085][ T83] ------------------------------------------------------ [ 47.282252][ T83] kworker/1:2/83 is trying to acquire lock: [ 47.288114][ T83] ffffffff874267c8 (minor_rwsem){++++}, at: usb_deregister_dev+0x95/0x230 [ 47.296802][ T83] [ 47.296802][ T83] but task is already holding lock: [ 47.305115][ T83] ffffffff874c5620 (open_disc_mutex){+.+.}, at: tower_disconnect+0x45/0x300 [ 47.313776][ T83] [ 47.313776][ T83] which lock already depends on the new lock. [ 47.313776][ T83] [ 47.324184][ T83] [ 47.324184][ T83] the existing dependency chain (in reverse order) is: [ 47.333183][ T83] [ 47.333183][ T83] -> #1 (open_disc_mutex){+.+.}: [ 47.340291][ T83] __mutex_lock+0x158/0x1360 [ 47.345385][ T83] tower_open+0xce/0x9b0 [ 47.350219][ T83] usb_open+0x1df/0x270 [ 47.354878][ T83] chrdev_open+0x219/0x5c0 [ 47.359910][ T83] do_dentry_open+0x494/0x1120 [ 47.365184][ T83] path_openat+0x1430/0x3f50 [ 47.370299][ T83] do_filp_open+0x1a1/0x280 [ 47.375304][ T83] do_sys_open+0x3c0/0x580 [ 47.380235][ T83] do_syscall_64+0xb7/0x580 [ 47.385257][ T83] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 47.391643][ T83] [ 47.391643][ T83] -> #0 (minor_rwsem){++++}: [ 47.398401][ T83] __lock_acquire+0x1f74/0x3eb0 [ 47.403765][ T83] lock_acquire+0x127/0x320 [ 47.409114][ T83] down_write+0x92/0x150 [ 47.413877][ T83] usb_deregister_dev+0x95/0x230 [ 47.419311][ T83] tower_disconnect+0xa8/0x300 [ 47.424584][ T83] usb_unbind_interface+0x1bd/0x8a0 [ 47.430458][ T83] device_release_driver_internal+0x42f/0x500 [ 47.437026][ T83] bus_remove_device+0x2dc/0x4a0 [ 47.442455][ T83] device_del+0x420/0xb10 [ 47.447289][ T83] usb_disable_device+0x211/0x690 [ 47.452820][ T83] usb_disconnect+0x284/0x8d0 [ 47.458114][ T83] hub_event+0x1454/0x3640 [ 47.463031][ T83] process_one_work+0x92b/0x1530 [ 47.468464][ T83] worker_thread+0x96/0xe20 [ 47.473586][ T83] kthread+0x318/0x420 [ 47.478215][ T83] ret_from_fork+0x24/0x30 [ 47.483120][ T83] [ 47.483120][ T83] other info that might help us debug this: [ 47.483120][ T83] [ 47.493322][ T83] Possible unsafe locking scenario: [ 47.493322][ T83] [ 47.500745][ T83] CPU0 CPU1 [ 47.506084][ T83] ---- ---- [ 47.511423][ T83] lock(open_disc_mutex); [ 47.515809][ T83] lock(minor_rwsem); [ 47.522362][ T83] lock(open_disc_mutex); [ 47.529266][ T83] lock(minor_rwsem); [ 47.533308][ T83] [ 47.533308][ T83] *** DEADLOCK *** [ 47.533308][ T83] [ 47.541430][ T83] 6 locks held by kworker/1:2/83: [ 47.546520][ T83] #0: ffff8881d9200628 ((wq_completion)usb_hub_wq){+.+.}, at: process_one_work+0x827/0x1530 [ 47.556655][ T83] #1: ffff8881d93c7dd0 ((work_completion)(&hub->events)){+.+.}, at: process_one_work+0x85b/0x1530 [ 47.567333][ T83] #2: ffff8881d5c5e800 (&dev->mutex){....}, at: hub_event+0x17c/0x3640 [ 47.575636][ T83] #3: ffff8881d90a7080 (&dev->mutex){....}, at: usb_disconnect+0x91/0x8d0 [ 47.584204][ T83] #4: ffff8881d90a5f10 (&dev->mutex){....}, at: device_release_driver_internal+0x23/0x500 [ 47.594899][ T83] #5: ffffffff874c5620 (open_disc_mutex){+.+.}, at: tower_disconnect+0x45/0x300 [ 47.604020][ T83] [ 47.604020][ T83] stack backtrace: [ 47.609912][ T83] CPU: 1 PID: 83 Comm: kworker/1:2 Not tainted 5.3.0+ #0 [ 47.616955][ T83] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.627429][ T83] Workqueue: usb_hub_wq hub_event [ 47.632432][ T83] Call Trace: [ 47.635722][ T83] dump_stack+0xca/0x13e [ 47.639939][ T83] check_noncircular+0x32e/0x3e0 [ 47.645502][ T83] ? save_stack+0x4c/0x80 [ 47.649923][ T83] ? print_circular_bug.isra.0+0x1e0/0x1e0 [ 47.655714][ T83] ? kobject_put+0x18c/0x280 [ 47.660286][ T83] ? usb_deregister_dev+0x89/0x230 [ 47.665462][ T83] ? tower_disconnect+0xa8/0x300 [ 47.670375][ T83] ? usb_unbind_interface+0x1bd/0x8a0 [ 47.675734][ T83] ? graph_lock+0x80/0x180 [ 47.680122][ T83] ? hlock_class+0x120/0x120 [ 47.684697][ T83] ? mark_lock+0xbc/0x1160 [ 47.689088][ T83] __lock_acquire+0x1f74/0x3eb0 [ 47.694017][ T83] ? mark_held_locks+0x9f/0xe0 [ 47.698752][ T83] ? lockdep_hardirqs_on+0x382/0x580 [ 47.704008][ T83] ? mark_held_locks+0xe0/0xe0 [ 47.708743][ T83] lock_acquire+0x127/0x320 [ 47.713219][ T83] ? usb_deregister_dev+0x95/0x230 [ 47.718311][ T83] down_write+0x92/0x150 [ 47.722526][ T83] ? usb_deregister_dev+0x95/0x230 [ 47.727611][ T83] ? __down_timeout+0x2d0/0x2d0 [ 47.732441][ T83] ? root_device_unregister+0x80/0x80 [ 47.737791][ T83] usb_deregister_dev+0x95/0x230 [ 47.742745][ T83] tower_disconnect+0xa8/0x300 [ 47.747575][ T83] usb_unbind_interface+0x1bd/0x8a0 [ 47.752747][ T83] ? usb_autoresume_device+0x60/0x60 [ 47.758008][ T83] device_release_driver_internal+0x42f/0x500 [ 47.764056][ T83] bus_remove_device+0x2dc/0x4a0 [ 47.768965][ T83] device_del+0x420/0xb10 [ 47.773266][ T83] ? __device_links_no_driver+0x240/0x240 [ 47.778957][ T83] ? usb_remove_ep_devs+0x3e/0x80 [ 47.783968][ T83] ? remove_intf_ep_devs+0x13f/0x1d0 [ 47.789228][ T83] usb_disable_device+0x211/0x690 [ 47.794222][ T83] usb_disconnect+0x284/0x8d0 [ 47.798879][ T83] hub_event+0x1454/0x3640 [ 47.803268][ T83] ? find_held_lock+0x2d/0x110 [ 47.808004][ T83] ? mark_held_locks+0xe0/0xe0 [ 47.812741][ T83] ? hub_port_debounce+0x260/0x260 [ 47.819215][ T83] ? rcu_read_lock_sched_held+0x9c/0xd0 [ 47.824737][ T83] ? rcu_read_lock_bh_held+0xb0/0xb0 [ 47.830003][ T83] process_one_work+0x92b/0x1530 [ 47.834923][ T83] ? pwq_dec_nr_in_flig