input: HID 045e:07da as /devices/platform/dummy_hcd.9/usb10/10-1/10-1:0.0/0003:045E:07DA.0028/input/input34 ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ kworker/0:14/4406 is trying to acquire lock: ffff8880604c9ee0 ( &hdev->ll_open_lock){+.+.}-{3:3}, at: hid_hw_open+0x23/0x160 drivers/hid/hid-core.c:2127 but task is already holding lock: ffff88804ba802c0 (&dev->mutex#2){+.+.}-{3:3}, at: input_open_device+0x4e/0x2e0 drivers/input/input.c:620 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&dev->mutex#2){+.+.}-{3:3}: __mutex_lock_common+0x1eb/0x2390 kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 input_disconnect_device drivers/input/input.c:748 [inline] __input_unregister_device+0x2e/0x320 drivers/input/input.c:2278 input_unregister_device+0x97/0xf0 drivers/input/input.c:2473 steam_client_ll_open+0x73/0x90 drivers/hid/hid-steam.c:640 hid_hw_open+0xdd/0x160 drivers/hid/hid-core.c:2132 hidraw_open+0x28f/0x8b0 drivers/hid/hidraw.c:289 chrdev_open+0x597/0x670 fs/char_dev.c:414 do_dentry_open+0x7ff/0xf80 fs/open.c:826 do_open fs/namei.c:3616 [inline] path_openat+0x2682/0x2f30 fs/namei.c:3750 do_filp_open+0x1b3/0x3e0 fs/namei.c:3777 do_sys_openat2+0x142/0x4a0 fs/open.c:1255 do_sys_open fs/open.c:1271 [inline] __do_sys_openat fs/open.c:1287 [inline] __se_sys_openat fs/open.c:1282 [inline] __x64_sys_openat+0x135/0x160 fs/open.c:1282 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 -> #0 (&hdev->ll_open_lock){+.+.}-{3:3}: check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain kernel/locking/lockdep.c:3788 [inline] __lock_acquire+0x2c33/0x7c60 kernel/locking/lockdep.c:5012 lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623 __mutex_lock_common+0x1eb/0x2390 kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_killable_nested+0x17/0x20 kernel/locking/mutex.c:758 hid_hw_open+0x23/0x160 drivers/hid/hid-core.c:2127 input_open_device+0x16c/0x2e0 drivers/input/input.c:640 kbd_connect+0xe9/0x130 drivers/tty/vt/keyboard.c:1581 input_attach_handler drivers/input/input.c:1046 [inline] input_register_device+0xda7/0x1140 drivers/input/input.c:2429 hidinput_connect+0x2440/0x2d90 drivers/hid/hid-input.c:2030 hid_connect+0x458/0xdf0 drivers/hid/hid-core.c:1983 hid_hw_start+0x99/0x100 drivers/hid/hid-core.c:2090 ms_probe+0x179/0x420 drivers/hid/hid-microsoft.c:391 hid_device_probe+0x271/0x360 drivers/hid/hid-core.c:2318 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x284/0xc80 drivers/base/dd.c:595 __driver_probe_device+0x18c/0x330 drivers/base/dd.c:755 driver_probe_device+0x4f/0x420 drivers/base/dd.c:785 __device_attach_driver+0x2b0/0x500 drivers/base/dd.c:907 bus_for_each_drv+0x175/0x200 drivers/base/bus.c:429 __device_attach+0x29b/0x460 drivers/base/dd.c:979 bus_probe_device+0xbc/0x1e0 drivers/base/bus.c:489 device_add+0xa00/0xfb0 drivers/base/core.c:3412 hid_add_device+0x389/0x530 drivers/hid/hid-core.c:2470 usbhid_probe+0xb92/0xf40 drivers/hid/usbhid/hid-core.c:1427 usb_probe_interface+0x5a0/0xaf0 drivers/usb/core/driver.c:396 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x284/0xc80 drivers/base/dd.c:595 __driver_probe_device+0x18c/0x330 drivers/base/dd.c:755 driver_probe_device+0x4f/0x420 drivers/base/dd.c:785 __device_attach_driver+0x2b0/0x500 drivers/base/dd.c:907 bus_for_each_drv+0x175/0x200 drivers/base/bus.c:429 __device_attach+0x29b/0x460 drivers/base/dd.c:979 bus_probe_device+0xbc/0x1e0 drivers/base/bus.c:489 device_add+0xa00/0xfb0 drivers/base/core.c:3412 usb_set_configuration+0x1991/0x1fd0 drivers/usb/core/message.c:2165 usb_generic_driver_probe+0x89/0x150 drivers/usb/core/generic.c:238 usb_probe_device+0x139/0x270 drivers/usb/core/driver.c:293 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x284/0xc80 drivers/base/dd.c:595 __driver_probe_device+0x18c/0x330 drivers/base/dd.c:755 driver_probe_device+0x4f/0x420 drivers/base/dd.c:785 __device_attach_driver+0x2b0/0x500 drivers/base/dd.c:907 bus_for_each_drv+0x175/0x200 drivers/base/bus.c:429 __device_attach+0x29b/0x460 drivers/base/dd.c:979 bus_probe_device+0xbc/0x1e0 drivers/base/bus.c:489 device_add+0xa00/0xfb0 drivers/base/core.c:3412 usb_new_device+0xd53/0x1640 drivers/usb/core/hub.c:2632 hub_port_connect drivers/usb/core/hub.c:5497 [inline] hub_port_connect_change drivers/usb/core/hub.c:5637 [inline] port_event drivers/usb/core/hub.c:5799 [inline] hub_event+0x2dd9/0x5560 drivers/usb/core/hub.c:5881 process_one_work+0x863/0x1000 kernel/workqueue.c:2310 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&dev->mutex#2 ); lock(&hdev->ll_open_lock); lock( &dev->mutex#2); lock(&hdev->ll_open_lock); *** DEADLOCK *** 8 locks held by kworker/0:14/4406: #0: ffff88801ba1bd38 ((wq_completion)usb_hub_wq ){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc90003acfd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 #2: ffff8880246a2220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:764 [inline] #2: ffff8880246a2220 (&dev->mutex){....}-{3:3}, at: hub_event+0x1a7/0x5560 drivers/usb/core/hub.c:5827 #3: ffff888021196220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:764 [inline] #3: ffff888021196220 (&dev->mutex){....}-{3:3}, at: __device_attach+0x85/0x460 drivers/base/dd.c:954 #4: ffff888073a321a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:764 [inline] #4: ffff888073a321a8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x85/0x460 drivers/base/dd.c:954 #5: ffff8880604c9ab0 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:764 [inline] #5: ffff8880604c9ab0 (&dev->mutex){....}-{3:3}, at: __device_attach+0x85/0x460 drivers/base/dd.c:954 #6: ffffffff8cd3e4e8 (input_mutex){+.+.}-{3:3} , at: input_register_device+0xb66/0x1140 drivers/input/input.c:2422 #7: ffff88804ba802c0 (&dev->mutex#2){+.+.}-{3:3}, at: input_open_device+0x4e/0x2e0 drivers/input/input.c:620 stack backtrace: CPU: 0 PID: 4406 Comm: kworker/0:14 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: usb_hub_wq hub_event Call Trace: dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106 check_noncircular+0x274/0x310 kernel/locking/lockdep.c:2133 check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain kernel/locking/lockdep.c:3788 [inline] __lock_acquire+0x2c33/0x7c60 kernel/locking/lockdep.c:5012 lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623 __mutex_lock_common+0x1eb/0x2390 kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_killable_nested+0x17/0x20 kernel/locking/mutex.c:758 hid_hw_open+0x23/0x160 drivers/hid/hid-core.c:2127 input_open_device+0x16c/0x2e0 drivers/input/input.c:640 kbd_connect+0xe9/0x130 drivers/tty/vt/keyboard.c:1581 input_attach_handler drivers/input/input.c:1046 [inline] input_register_device+0xda7/0x1140 drivers/input/input.c:2429 hidinput_connect+0x2440/0x2d90 drivers/hid/hid-input.c:2030 hid_connect+0x458/0xdf0 drivers/hid/hid-core.c:1983 hid_hw_start+0x99/0x100 drivers/hid/hid-core.c:2090 ms_probe+0x179/0x420 drivers/hid/hid-microsoft.c:391 hid_device_probe+0x271/0x360 drivers/hid/hid-core.c:2318 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x284/0xc80 drivers/base/dd.c:595 __driver_probe_device+0x18c/0x330 drivers/base/dd.c:755 driver_probe_device+0x4f/0x420 drivers/base/dd.c:785 __device_attach_driver+0x2b0/0x500 drivers/base/dd.c:907 bus_for_each_drv+0x175/0x200 drivers/base/bus.c:429 __device_attach+0x29b/0x460 drivers/base/dd.c:979 bus_probe_device+0xbc/0x1e0 drivers/base/bus.c:489 device_add+0xa00/0xfb0 drivers/base/core.c:3412 hid_add_device+0x389/0x530 drivers/hid/hid-core.c:2470 usbhid_probe+0xb92/0xf40 drivers/hid/usbhid/hid-core.c:1427 usb_probe_interface+0x5a0/0xaf0 drivers/usb/core/driver.c:396 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x284/0xc80 drivers/base/dd.c:595 __driver_probe_device+0x18c/0x330 drivers/base/dd.c:755 driver_probe_device+0x4f/0x420 drivers/base/dd.c:785 __device_attach_driver+0x2b0/0x500 drivers/base/dd.c:907 bus_for_each_drv+0x175/0x200 drivers/base/bus.c:429 __device_attach+0x29b/0x460 drivers/base/dd.c:979 bus_probe_device+0xbc/0x1e0 drivers/base/bus.c:489 device_add+0xa00/0xfb0 drivers/base/core.c:3412 usb_set_configuration+0x1991/0x1fd0 drivers/usb/core/message.c:2165 usb_generic_driver_probe+0x89/0x150 drivers/usb/core/generic.c:238 usb_probe_device+0x139/0x270 drivers/usb/core/driver.c:293 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x284/0xc80 drivers/base/dd.c:595 __driver_probe_device+0x18c/0x330 drivers/base/dd.c:755 driver_probe_device+0x4f/0x420 drivers/base/dd.c:785 __device_attach_driver+0x2b0/0x500 drivers/base/dd.c:907 bus_for_each_drv+0x175/0x200 drivers/base/bus.c:429 __device_attach+0x29b/0x460 drivers/base/dd.c:979 bus_probe_device+0xbc/0x1e0 drivers/base/bus.c:489 device_add+0xa00/0xfb0 drivers/base/core.c:3412 usb_new_device+0xd53/0x1640 drivers/usb/core/hub.c:2632 hub_port_connect drivers/usb/core/hub.c:5497 [inline] hub_port_connect_change drivers/usb/core/hub.c:5637 [inline] port_event drivers/usb/core/hub.c:5799 [inline] hub_event+0x2dd9/0x5560 drivers/usb/core/hub.c:5881 process_one_work+0x863/0x1000 kernel/workqueue.c:2310 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 microsoft 0003:045E:07DA.0028: input,hidraw0: USB HID v0.00 Device [HID 045e:07da] on usb-dummy_hcd.9-1/input0 usb 10-1: USB disconnect, device number 4