In all InnoDB row formats, the pointers or lengths stored in the record header can be at most 14 bits, that is, count up to 16383.
In ROW_FORMAT=REDUNDANT, this limits the maximum possible record length to 16383 bytes. In other ROW_FORMAT, it could merely limit the maximum length of variable-length fields.

When MySQL 5.7 introduced innodb_page_size=32k and 64k, the maximum record length was limited to 16383 bytes (I hope 16383, not 16384, to be able to distinguish from a record whose length is 0 bytes). This change is present in MariaDB Server 10.2.

We should fix MariaDB Server 10.1 accordingly.
There already is a test for this: innodb.innodb-64k