Valgrind claims there is unfreed memory. Is this bad?

Question

Valgrind gives me the following leak summary on my code. However, I have freed all malloc\'ed memory. Is this a bad thing, or is this normal? My program is in c.

Answer 1

It would be a good idea to zero out pointers that were free()'ed, which would cause a crash upon (incorrectly) trying to dereference them again.