WARNING in r871xu_dev_remove

[syzbot <syzbot+80899a8a8efe8968cde7@syzkaller.appspotmail.com>]

Hello,

syzbot found the following crash on:

HEAD commit:    eea39f24 usb-fuzzer: main usb gadget fuzzer driver
git tree:       https://github.com/google/kasan.git usb-fuzzer
console output: https://syzkaller.appspot.com/x/log.txt?x=163ae012600000
kernel config:  https://syzkaller.appspot.com/x/.config?x=d0c62209eedfd54e
dashboard link: https://syzkaller.appspot.com/bug?extid=80899a8a8efe8968cde7
compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1739cb0e600000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=154fcc2e600000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+80899a8a8efe8968cde7@syzkaller.appspotmail.com

------------[ cut here ]------------
WARNING: CPU: 1 PID: 83 at net/core/dev.c:8167  
rollback_registered_many.cold+0x41/0x1bc net/core/dev.c:8167
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 83 Comm: kworker/1:2 Not tainted 5.3.0-rc5+ #28
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
Workqueue: usb_hub_wq hub_event
Call Trace:
  __dump_stack lib/dump_stack.c:77 [inline]
  dump_stack+0xca/0x13e lib/dump_stack.c:113
  panic+0x2a3/0x6da kernel/panic.c:219
  __warn.cold+0x20/0x4a kernel/panic.c:576
  report_bug+0x262/0x2a0 lib/bug.c:186
  fixup_bug arch/x86/kernel/traps.c:179 [inline]
  fixup_bug arch/x86/kernel/traps.c:174 [inline]
  do_error_trap+0x12b/0x1e0 arch/x86/kernel/traps.c:272
  do_invalid_op+0x32/0x40 arch/x86/kernel/traps.c:291
  invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1028
RIP: 0010:rollback_registered_many.cold+0x41/0x1bc net/core/dev.c:8167
Code: ff e8 c7 26 90 fc 48 c7 c7 40 ec 63 86 e8 24 c8 7a fc 0f 0b e9 93 be  
ff ff e8 af 26 90 fc 48 c7 c7 40 ec 63 86 e8 0c c8 7a fc <0f> 0b 4c 89 e7  
e8 f9 12 34 fd 31 ff 41 89 c4 89 c6 e8 bd 27 90 fc
RSP: 0018:ffff8881d938f6a8 EFLAGS: 00010286
RAX: 0000000000000024 RBX: ffff8881d2a10000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff81288cfd RDI: ffffed103b271ec7
RBP: ffff8881d938f7d8 R08: 0000000000000024 R09: fffffbfff11ad794
R10: fffffbfff11ad793 R11: ffffffff88d6bc9f R12: ffff8881d2a10070
R13: ffff8881d938f768 R14: dffffc0000000000 R15: 0000000000000000
  rollback_registered+0xf2/0x1c0 net/core/dev.c:8243
  unregister_netdevice_queue net/core/dev.c:9290 [inline]
  unregister_netdevice_queue+0x1d7/0x2b0 net/core/dev.c:9283
  unregister_netdevice include/linux/netdevice.h:2631 [inline]
  unregister_netdev+0x18/0x20 net/core/dev.c:9331
  r871xu_dev_remove+0xe2/0x215 drivers/staging/rtl8712/usb_intf.c:604
  usb_unbind_interface+0x1bd/0x8a0 drivers/usb/core/driver.c:423
  __device_release_driver drivers/base/dd.c:1134 [inline]
  device_release_driver_internal+0x42f/0x500 drivers/base/dd.c:1165
  bus_remove_device+0x2dc/0x4a0 drivers/base/bus.c:556
  device_del+0x420/0xb10 drivers/base/core.c:2339
  usb_disable_device+0x211/0x690 drivers/usb/core/message.c:1237
  usb_disconnect+0x284/0x8d0 drivers/usb/core/hub.c:2199
  hub_port_connect drivers/usb/core/hub.c:4949 [inline]
  hub_port_connect_change drivers/usb/core/hub.c:5213 [inline]
  port_event drivers/usb/core/hub.c:5359 [inline]
  hub_event+0x1454/0x3640 drivers/usb/core/hub.c:5441
  process_one_work+0x92b/0x1530 kernel/workqueue.c:2269
  process_scheduled_works kernel/workqueue.c:2331 [inline]
  worker_thread+0x7ab/0xe20 kernel/workqueue.c:2417
  kthread+0x318/0x420 kernel/kthread.c:255
  ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
Kernel Offset: disabled
Rebooting in 86400 seconds..


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