Pointers bss中的静态指针溢出
我正在使用关于bss中静态指针溢出的w00w00练习。我将缓冲区和缓冲区指针放入静态结构中,以强制溢出指针。否则,它会将指针放在和缓冲区之前,不会发生溢出Pointers bss中的静态指针溢出,pointers,static,overflow,address-sanitizer,Pointers,Static,Overflow,Address Sanitizer,我正在使用关于bss中静态指针溢出的w00w00练习。我将缓冲区和缓冲区指针放入静态结构中,以强制溢出指针。否则,它会将指针放在和缓冲区之前,不会发生溢出 #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <string.h> #include <errno.h> #define BUFSIZE 16 #de
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#define BUFSIZE 16
#define ADDRLEN 4 /* # of bytes in an address */
int main()
{
u_long diff;
struct buf {
char buf[BUFSIZE];
char *bufptr ;
} ;
static struct buf a;
a.bufptr = a.buf, diff = (u_long)a.buf - (u_long)&a.bufptr;
printf("bufptr (%p) = %p, buf = %p, diff = 0x%x (%d) bytes\n",
&a.bufptr,a.bufptr, a.buf, diff, diff);
memset(a.buf, 'A', (u_int)(diff + ADDRLEN));
printf("bufptr (%p) = %p, buf = %p, diff = 0x%x (%d) bytes\n",
&a.bufptr, a.bufptr, a.buf, diff, diff);
return 0;
}
是否有标志或方法强制溢出
编辑: 我解决了这个问题。差异结果为-16。 我很生气它看起来像这样
diff = (u_long)&a.bufptr - (u_long)a.buf
现在它可以正常工作了 尝试大于结构大小但不足以解释为负数的大小:
memset(a.buf, 'A', 1024);
另外,请确保使用-fno common
进行编译,如中所述
memset(a.buf, 'A', 1024);