On Thu, Dec 16, 2021 at 11:16:26AM +0100, Oliver Neukum wrote: > > On 15.12.21 15:57, Greg KH wrote: > > On Wed, Dec 15, 2021 at 03:47:55PM +0100, Oliver Neukum wrote: > >> On 09.12.21 16:47, Greg KH wrote: > >>> Why not use usb_find_common_endpoints() and/or the other helper > >>> functions instead? that's what they were created for. > >> Hi, > >> > >> which one would I use? In this case I already know the endpoints > >> to be verified. > > I have no context here so I have no idea, sorry. > > usbnet has three ways to match the endpoints > > 1) the subdriver provides a method > > 2) a heuristic to find the endpoints is used (that should be converted > to the new API) > > 3) they are given nummerically by the subdriver > > It turns out that #3 needs to verify the endpoints against malicious > devices. > So the following questions > > a) should that verification go into usbcore the usb_find_common_endpoints() functions are in the usbcore for drivers to use for this type of problem. > b) what possible ways for a malicious device to spoof us can you come > up with Start with: - invalid endpoint sizes and types - invalid data being sent on valid endpoint types and you will catch almost all possible errors. thanks, greg k-h
