I have a laptop with 4 USB ports, and I have an external 4 port splitter that I purchased off amazon. Plugged into that is an external USB audio card. The audio card has a line-in port and an audio output. But, when I run lsusb, an HID (human interace device) is also detected:
/: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=ehci-pci/6p, 480M |__ Port 2: Dev 15, If 0, Class=Hub, Driver=hub/4p, 480M |__ Port 3: Dev 16, If 0, Class=Audio, Driver=snd-usb-audio, 12M |__ Port 3: Dev 16, If 1, Class=Audio, Driver=snd-usb-audio, 12M |__ Port 3: Dev 16, If 2, Class=Audio, Driver=snd-usb-audio, 12M |__ Port 3: Dev 16, If 3, Class=Human Interface Device, Driver=usbhid, 12M
So I have three questions.. Why are their 3 different audio interfaces showing up, and what legitamate use would an HID server on an audio card? I thought that HID controllers were for devices like keyboards, mice, or perhaps cameras. I also know that they are an attractive attack vector (like the rubber ducky). Is this normal?
Secondly, listed on port 1, and also when all usb devices are removed from my computer, I see this in output of the
/: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=ehci-pci/6p, 480M |__ Port 5: Dev 2, If 0, Class=Video, Driver=uvcvideo, 480M |__ Port 5: Dev 2, If 1, Class=Video, Driver=uvcvideo, 480M
I do have a webcam and microphone inside the laptop, but not inserted in anything USB. However,
lspci does not report any other video controllers, so I assume that's just the internal camera.
Finally, why would a wireless mouse show up as a keyboard? I assume it's because this mouse has a couple other buttons on them (although none actually work in linux):
*-usb description: Keyboard product: 2.4G Wireless Mouse vendor: MOSART Semi. physical id: 1 bus info: usb@8:1 version: 1.11 capabilities: usb-1.10 configuration: driver=usbhid maxpower=100mA speed=12Mbit/s
Is any of this abnormal? What legitamate uses do USB HID controllers serve?