/*kbof.c test kernel buffer overflow Vulnerability
 *                      --- alert7 < alert7@xfocus.org >
 *gcc -O3 -c -I/usr/src/linux/include kbof.c
 */

#define MODULE
#define __KERNEL__
#include <linux/kernel.h>
#include <linux/module.h>
#include <asm/unistd.h>
#include <asm/uaccess.h>
#include <sys/syscall.h>
#include <linux/slab.h>

#define __NR_function   240     //linux not use

extern void* sys_call_table[];

int (*old_function) (void );

asmlinkage int test(unsigned int len,char * code) {
        char buf[256];
        //strcpy(buf,code);
		memcpy(buf,code,len);

}
asmlinkage int new_function(unsigned int len, char * buf) {
        char *  code = kmalloc(len, GFP_KERNEL);

        if (code ==NULL) goto out;

        if (copy_from_user(code, buf, len))
                goto out;

        test(len,code);
out:
        return 0;
}

int init_module(void) {
  old_function = sys_call_table[__NR_function];
  sys_call_table[__NR_function] = new_function;
  printk("<1>kbof test loaded...\n");
  return 0;
}

void cleanup_module(void) {
  sys_call_table[__NR_function] = old_function;
  printk("<1>kbof test unloaded...\n");
}