TI Stellaris EKK-LM4F232 memory overlap issue (heap and stack)

I am facing a problem in an application (MDK4.23) I have written for my LM4F232 board.

I have a function which defines a struct variable. This function(parent) in turn calls another function(child) within which a malloc is being done. For some reason the mallc ed memory and the address of the struct variable are close to each other.

So when I initialize my malloced memory I in turn lose the contents of the struct variable from the parent function (which calls the child).

Does anyone have any idea why this happens. Is there something I am not taking care off in my scatter file which is causing this.

I think stack and heap are sometimes allocated on a single block of memory with half being used by each and each of the memories growing outwards. Does anyone know how to allocate this stack/heap memory using the scatter file. A sample scatter file for the same would be much appreciated.

My present scatter file is this :

LR_IROM 0x00000000 0x00040000
{
    ;
    ; Specify the Execution Address of the code and the size.
    ;
    ER_IROM 0x00000000 0x00040000
    {
        *.o (RESET, +First)
        * (InRoot$$Sections, +RO)
    }

    ;
    ; Specify the Execution Address of the data area.
    ;
    RW_IRAM 0x20000000 0x00008000
    {
        ;
        ; Uncomment the following line in order to use IntRegister().
        ;
        ;* (vtable, +First)
        * (+RW, +ZI)
    }
}

Thanks.