------------[ cut here ]------------
URB 00000000db637822 submitted while active
WARNING: CPU: 0 PID: 7673 at drivers/usb/core/urb.c:363 usb_submit_urb+0x11cf/0x14e0 drivers/usb/core/urb.c:363
Kernel panic - not syncing: panic_on_warn set ...

CPU: 0 PID: 7673 Comm: kworker/0:4 Not tainted 4.19.0-rc6+ #49
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events_power_efficient hub_init_func2
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1c4/0x2b4 lib/dump_stack.c:113
kobject: 'loop4' (000000003bd5ef5a): kobject_uevent_env
 panic+0x238/0x4e7 kernel/panic.c:184
kobject: 'loop4' (000000003bd5ef5a): fill_kobj_path: path = '/devices/virtual/block/loop4'
 __warn.cold.8+0x163/0x1ba kernel/panic.c:536
 report_bug+0x254/0x2d0 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:178 [inline]
 do_error_trap+0x1fc/0x4d0 arch/x86/kernel/traps.c:296
kobject: 'loop3' (00000000e1fe1139): kobject_uevent_env
kobject: 'loop3' (00000000e1fe1139): fill_kobj_path: path = '/devices/virtual/block/loop3'
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:316
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:993
RIP: 0010:usb_submit_urb+0x11cf/0x14e0 drivers/usb/core/urb.c:363
Code: ee e8 95 df 83 fc 45 84 ed 0f 85 e2 f6 ff ff e8 b7 de 83 fc 48 89 de 48 c7 c7 20 71 71 88 c6 05 6d a1 f3 04 01 e8 91 b1 4d fc <0f> 0b e9 c0 f6 ff ff c7 45 a0 01 00 00 00 e9 65 f7 ff ff 41 bc ed
RSP: 0018:ffff88018199f4f0 EFLAGS: 00010282
RAX: 0000000000000000 RBX: ffff8801d2e62100 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff81650405 RDI: 0000000000000005
RBP: ffff88018199f560 R08: ffff8801d3e3c2c0 R09: ffffed003b5c4fe8
R10: ffffed003b5c4fe8 R11: ffff8801dae27f47 R12: 00000000fffffff0
R13: 0000000000000000 R14: 0000000000000009 R15: ffff88018199f6f8
 hub_activate+0xcab/0x1940 drivers/usb/core/hub.c:1214
 hub_init_func2+0x1e/0x30 drivers/usb/core/hub.c:1239
 process_one_work+0xc90/0x1b90 kernel/workqueue.c:2153
 worker_thread+0x17f/0x1390 kernel/workqueue.c:2296
 kthread+0x35a/0x420 kernel/kthread.c:246
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:413
Kernel Offset: disabled
Rebooting in 86400 seconds..