usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
usb 1-1: Product: syz
usb 1-1: Manufacturer: syz
usb 1-1: SerialNumber: syz
usb 1-1: config 0 descriptor??
usbtv 1-1:0.0: Fushicai USBTV007 Audio-Video Grabber
usb 1-1: USB disconnect, device number 2
============================================
WARNING: possible recursive locking detected
6.7.0-rc2-syzkaller #0 Not tainted
--------------------------------------------
kworker/1:2/2216 is trying to acquire lock:
ffff88810eb81b70 (&usbtv->vb2q_lock){+.+.}-{3:3}, at: vb2_video_unregister_device+0x6a/0xb0 drivers/media/common/videobuf2/videobuf2-v4l2.c:1272

but task is already holding lock:
ffff88810eb81b70 (&usbtv->vb2q_lock){+.+.}-{3:3}, at: usbtv_video_free+0x1d/0x70 drivers/media/usb/usbtv/usbtv-video.c:966

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&usbtv->vb2q_lock);
  lock(&usbtv->vb2q_lock);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

7 locks held by kworker/1:2/2216:
 #0: ffff88810425ef38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2605 [inline]
 #0: ffff88810425ef38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x1f2/0x4d0 kernel/workqueue.c:2703
 #1: ffffc90000e5fe58 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2605 [inline]
 #1: ffffc90000e5fe58 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x1f2/0x4d0 kernel/workqueue.c:2703
 #2: ffff88810ca6b190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:992 [inline]
 #2: ffff88810ca6b190 (&dev->mutex){....}-{3:3}, at: hub_event+0x7e/0x1b20 drivers/usb/core/hub.c:5791
 #3: ffff888119608990 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:992 [inline]
 #3: ffff888119608990 (&dev->mutex){....}-{3:3}, at: usb_disconnect+0x80/0x290 drivers/usb/core/hub.c:2251
 #4: ffff88811960f160 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:992 [inline]
 #4: ffff88811960f160 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1095 [inline]
 #4: ffff88811960f160 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0x47/0x2a0 drivers/base/dd.c:1292
 #5: ffff88810eb81b70 (&usbtv->vb2q_lock){+.+.}-{3:3}, at: usbtv_video_free+0x1d/0x70 drivers/media/usb/usbtv/usbtv-video.c:966
 #6: ffff88810eb81ae0 (&usbtv->v4l2_lock){+.+.}-{3:3}, at: usbtv_video_free+0x2e/0x70 drivers/media/usb/usbtv/usbtv-video.c:967

stack backtrace:
CPU: 1 PID: 2216 Comm: kworker/1:2 Not tainted 6.7.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
Workqueue: usb_hub_wq hub_event
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x8d/0xe0 lib/dump_stack.c:106
 check_deadlock kernel/locking/lockdep.c:3062 [inline]
 validate_chain kernel/locking/lockdep.c:3855 [inline]
 __lock_acquire+0x10ba/0x2490 kernel/locking/lockdep.c:5136
 lock_acquire+0xea/0x270 kernel/locking/lockdep.c:5753
 __mutex_lock_common kernel/locking/mutex.c:603 [inline]
 __mutex_lock+0x99/0x9a0 kernel/locking/mutex.c:747
 vb2_video_unregister_device+0x6a/0xb0 drivers/media/common/videobuf2/videobuf2-v4l2.c:1272
 usbtv_video_free+0x42/0x70 drivers/media/usb/usbtv/usbtv-video.c:970
 usbtv_disconnect+0x2c/0x50 drivers/media/usb/usbtv/usbtv-core.c:138
 usb_unbind_interface+0xb7/0x260 drivers/usb/core/driver.c:458
 device_remove drivers/base/dd.c:569 [inline]
 __device_release_driver drivers/base/dd.c:1272 [inline]
 device_release_driver_internal+0x1a4/0x2a0 drivers/base/dd.c:1295
 bus_remove_device+0x147/0x190 drivers/base/bus.c:574
 device_del+0x22b/0x370 drivers/base/core.c:3814
 usb_disable_device+0x78/0x1f0 drivers/usb/core/message.c:1416
 usb_disconnect+0xfc/0x290 drivers/usb/core/hub.c:2260
 hub_port_connect drivers/usb/core/hub.c:5303 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5603 [inline]
 port_event drivers/usb/core/hub.c:5763 [inline]
 hub_event+0xc2f/0x1b20 drivers/usb/core/hub.c:5845
 process_one_work kernel/workqueue.c:2630 [inline]
 process_scheduled_works+0x250/0x4d0 kernel/workqueue.c:2703
 worker_thread+0x23d/0x300 kernel/workqueue.c:2784
 kthread+0xe9/0x100 kernel/kthread.c:388
 ret_from_fork+0x32/0x40 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:242
 </TASK>