Re: INFO: rcu detected stall in hub_event

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer still triggered  
crash:
BUG: found invalid parent_idx

microsoft 0003:045E:07DA.0001: Field 0 ffff8881c0e00000 maxusage 4899
microsoft 0003:045E:07DA.0001: Usage 72 ffff8881c0e00730
microsoft 0003:045E:07DA.0001: collection 0 ffff8881d91be200 type 0 parent 0
microsoft 0003:045E:07DA.0001: BUG: found invalid parent_idx
microsoft 0003:045E:07DA.0001: Start report ffff8881cb82e000 maxfield 1
microsoft 0003:045E:07DA.0001: Field 0 ffff8881c0e00000 maxusage 4899
microsoft 0003:045E:07DA.0001: Usage 72 ffff8881c0e00730
microsoft 0003:045E:07DA.0001: collection 0 ffff8881d91be200 type 0 parent 0
microsoft 0003:045E:07DA.0001: BUG: found invalid parent_idx
microsoft 0003:045E:07DA.0001: No inputs registered, leaving
microsoft 0003:045E:07DA.0001: hidraw0: USB HID v0.00 Device [HID  
045e:07da] on usb-dummy_hcd.5-1/input0
microsoft 0003:045E:07DA.0001: no inputs found
microsoft 0003:045E:07DA.0001: could not initialize ff, continuing anyway
usb 6-1: USB disconnect, device number 3


Tested on:

commit:         46178223 usb: gadget: add raw-gadget interface
git tree:       https://github.com/google/kasan.git
console output: https://syzkaller.appspot.com/x/log.txt?x=14bb93cee00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=99c88c44660624e7
dashboard link: https://syzkaller.appspot.com/bug?extid=ec5f884c4a135aa0dbb9
compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
patch:          https://syzkaller.appspot.com/x/patch.diff?x=11c28d5ee00000