You shouldn't allocate heap space for a pointer in blocking_pipe_read. Also, it looks like you're leaking it in the else branch. Just allocate a pointer on th

You shouldn't allocate heap space for a pointer in blocking_pipe_read. Also, it looks like you're leaking it in the else branch. Just allocate a pointer on the stack, read into it, and then assign the value into the provided space: void *msg_ptr; read(..., &msg_ptr, sizeof msg_ptr); *data = msg_ptr;