The vendor-ID guess rejects any device with a driver bound, on the
reasoning that libfprint drives readers from userspace so a real one sits
there unbound. But libusb claims interfaces through a synthetic usbfs
driver, so the reader binds one for as long as fprintd holds the claim —
which is exactly while it is being enrolled or verified against.
Readers that name themselves take the product-string branch and never
reach this, so the exposure is the ones that don't: Goodix 27c6:6594
reports "Goodix USB2.0 MISC", matches on vendor ID alone, and drops out
of detection mid-authentication. The menu entry disappears and the
first-run invitation stops firing while the reader is in use.
Ignore a driver link that resolves to usbfs, and keep rejecting the real
ones — usbio-bridge, usbhid, uvcvideo — including on a device that has
both.
Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>
