Why would buffer overruns cause segmentation faults when accessing an integer?

Question

During a call to function B() from function A(), B() allocates a 100-char array and fills it several times, including once with a 101-character string and once with a 110 ch

Answer 1

The most likely explanation from you description is that the overrun in B corrupts the saved frame pointer on the stack for A. So after B returns, A has garbage in its frame pointer and crashes when it tries to access a local variable.