I have a very similar bug in Xubuntu 16.04 and 16.10. I have two small
Arduino semi-compatible stm32f103c8t6 based microcontroller boards with
USB ports. When I plug the idProduct=3 board in, the system fails to
load the ttyACM driver and the board doesn't work. But the weird thing
is that even though I disconnected the idProduct=3 board and powered
down the system and rebooted, when I plug the idProduct=4 board in, the
system detects and declares the presence of the idProduct=3 board and
shows product id and serial number of the idProduct=3 board, even though
the idProduct=3 board is not connected and has not been connected since
before the last boot. Then the system seems to realize its mistake and
claims to disconnect the idProduct=3 board (which is not physically
connected) and it detects and connects to the idProduct=4 board
correctly and loads the ACM driver correctly and the idProduct=4 board
works. I was using 16.04 when I discovered this problem, so I upgraded
to 16.10, but the problem is the same. This problem has persisted
through several reboots and connecting the boards in different orders.

There must be some kind of cache file for USB product id and serial
numbers that persists between reboots and even kernel and system version
upgrades. Does anybody know how I can clear the cache?

Here's the output of tail -f /var/log/kern.log  when connecting the
idProduct=4 board. Remember, at the time of this log the idProduct=3
board was not and had not been plugged in since before the last boot.
This is showing the false detection of the idProduct=3 board upon
insertion of the idProduct=4 board.


==> /var/log/kern.log <==
Feb 12 20:07:57 mybox kernel: [   85.064070] usb 3-4: new full-speed USB device 
number 2 using ohci-pci
Feb 12 20:07:58 mybox kernel: [   85.279854] usb 3-4: New USB device found, 
idVendor=1eaf, idProduct=0003
Feb 12 20:07:58 mybox kernel: [   85.279869] usb 3-4: New USB device strings: 
Mfr=1, Product=2, SerialNumber=3
Feb 12 20:07:58 mybox kernel: [   85.279877] usb 3-4: Product: Maple 003
Feb 12 20:07:58 mybox kernel: [   85.279884] usb 3-4: Manufacturer: LeafLabs
Feb 12 20:07:58 mybox kernel: [   85.279890] usb 3-4: SerialNumber: LLM 003
Feb 12 20:07:59 mybox kernel: [   86.307465] usb 3-4: USB disconnect, device 
number 2
Feb 12 20:07:59 mybox kernel: [   86.828222] usb 3-4: new full-speed USB device 
number 3 using ohci-pci
Feb 12 20:07:59 mybox kernel: [   87.049880] usb 3-4: New USB device found, 
idVendor=1eaf, idProduct=0004
Feb 12 20:07:59 mybox kernel: [   87.049895] usb 3-4: New USB device strings: 
Mfr=1, Product=2, SerialNumber=0
Feb 12 20:07:59 mybox kernel: [   87.049903] usb 3-4: Product: Maple
Feb 12 20:07:59 mybox kernel: [   87.049910] usb 3-4: Manufacturer: LeafLabs
Feb 12 20:07:59 mybox kernel: [   87.125930] cdc_acm 3-4:1.0: ttyACM0: USB ACM 
device
Feb 12 20:07:59 mybox kernel: [   87.134810] usbcore: registered new interface 
driver cdc_acm
Feb 12 20:07:59 mybox kernel: [   87.134837] cdc_acm: USB Abstract Control 
Model driver for USB modems and ISDN adapters

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https://bugs.launchpad.net/bugs/1539348

Title:
  udevadm info reports wrong ID_MODEL_ID and ID_VENDOR_ID for USB serial
  port

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