Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
media: rc: igorplugusb: fix control request setup packet
Commit eac69475b01f (“media: rc: igorplugusb: heed coherency rules”) changed the control request storage from an embedded struct to an allocated pointer so it can obey DMA coherency rules.
However, the driver still passes &ir->request to usb_fill_control_urb(). That points the URB setup packet at the pointer field itself rather than at the allocated struct usb_ctrlrequest.
USB core then interprets pointer bytes as the setup packet. This can produce an invalid bRequestType and trigger the control direction warning reported by syzbot:
usb 2-1: BOGUS control dir, pipe 80003580 doesn’t match bRequestType 0
Pass ir->request itself as the setup packet.