sample code for overflow in stack

Hello Can you give me 开发者_JS百科a sample code for overflow in stack with c or .net ? and say me how do you resolve this bug.

Thank you

How about:

static void f(void) {
    f();
}
int main (void) {
    f();
    return 0;
}

That should give you a very nice stack overflow, the solution to which is: don't do that.

#include <string.h>

void function( char *str ) {
   char buf[8];

   strcpy(buffer,str);
}

void main( int argc, char *argv[] ) {
  function( argv[1] );
}

Classic example. strcpy() copies without checking any sizes. So, if your source string (str) is bigger than the buffer (buf) you will get a buffer overflow. Making it say 16chars you will get a stack overflow.

You can resolve this bug by using a safer function like strncpy.

int factorial(int x)
{
    if (x == 1 || x == 0) return 1;
    return factorial(x-1) * x;
}

factorial(-1);

Make sure recursive functions always reach a base case somehow.

int factorial(int x)
{
    if (x < 0) return 0;
    if (x == 1 || x == 0) return 1;
    return factorial(x-1) *x;
}

factorial(-1);

Do you mean running out of stack space, or doing something malicious?

The classic article on overflowing the stack maliciously:

http://insecure.org/stf/smashstack.html

If you mean just running out of stack space, all you need to do is have a recursive function that ends up allocating too much space on the stack, and running out:

int foo()
{
    int something = 4;
    foo();
    return something; /* Yeah, we never get here */
}