CVE-2026-43291 Linux内核NFC参数验证漏洞

/* * PoC for CVE-2026-43291 * This code demonstrates the logic flaw in NFC NCI parameter validation. * It simulates sending a variable-length packet which would be rejected * by the vulnerable kernel checking against sizeof(struct). */ #include <stdio.h> #include <string.h> #include <stdlib.h> // Simulated NCI Data Header Structure (Fixed part) struct nci_data_hdr { unsigned char mt; unsigned char pbf; unsigned char gid; unsigned char oid; unsigned char plen; // Payload length }; int main() { // Scenario: A valid NCI packet with a payload of 10 bytes unsigned int header_size = sizeof(struct nci_data_hdr); unsigned int payload_size = 10; unsigned int total_packet_size = header_size + payload_size; printf("[*] NCI Header Size (sizeof struct): %d bytes\n", header_size); printf("[*] Valid Packet Total Size (Header + Payload): %d bytes\n", total_packet_size); // Vulnerability Logic Simulation // The buggy code checks: if (total_packet_size > header_size) return error; if (total_packet_size > header_size) { printf("[!] VULNERABILITY TRIGGERED: Packet rejected because it exceeds sizeof(struct).\n"); printf("[!] Result: Denial of Service (DoS) - NFC communication blocked.\n"); return 1; } printf("[+] Packet accepted (System patched).\n"); return 0; }