Linux assigns an fe80::/64 address to an interface. Shouldn't that be fe80::/10?
The address space allocated to link-local addresses is fe80::/10, but the next 54 bits are defined to be all zeroes, so the effective range is fe80::/64. Which puts it in line with the usual custom for IPv6 addresses.
RFC 4291:
2.5.6. Link-Local IPv6 Unicast Addresses Link-Local addresses are for use on a single link. Link-Local addresses have the following format: | 10 | | bits | 54 bits | 64 bits | +----------+-------------------------+----------------------------+ |1111111010| 0 | interface ID | +----------+-------------------------+----------------------------+