dangling pointer, linux vs solaris

When running a c application on linux I have a dangling pointer, which leads to core dump, when trying to access the memory it is pointing to, but only after a very long running time,
and it does not seem to occur when running on solaris.
The thread executing does not reallocate the same memory once it is freed before trying to use the pointer in question.

I know Solaris does not allow other applications to allocate the same memory,
but does Linux, once the memory has been freed?

I am trying to gauge whether this can and/or will core dump on Solaris or do I only need to worry about it running under Linux.