memcheck/tests/badrw.c

#include <stdlib.h>

int main(void)
{
   void* x = malloc(10);

   int   *x4;
   short *x2;
   char  *x1;
   int    y4;
   short  y2;
   char   y1;

   x4 = x-4;
   x2 = x-4;
   x1 = x-1;

   // Invalid reads and writes of sizes 4, 2, 1
   y4 = *x4;
   *x4 = y4;

   y2 = *x2;
   *x2 = y2;

   y1 = *x1;
   *x1 = y1;
   
   return 0;
}