Quadratic Probing Infinite Loop?
No. It means you should count how many slots you have checked, and if you have checked more than the available number of slots, you resize the table. 

In practice, if you regularly visit more than ten slots, then either the hash function is bad (nothing you can do about it while your program is running), or your load factor is too large. Not finding an empty slot will only happen if an attacker can decide your hash values.