CVE-2026-43274 Linux内核越界访问漏洞

/* * PoC Concept for CVE-2026-43274 * This demonstrates the logic error in indexing the cluster_cfg array. * Requires a kernel environment with the vulnerable driver and specific hardware topology. */ #include <stdio.h> #include <stdlib.h> // Simulating the vulnerable logic void vulnerable_logic(int *cluster_cfg, int num_cpus, int hartid) { // Vulnerability: using hartid directly as index // If hartid (e.g., 4) >= num_cpus (e.g., 4), this is OOB. printf("Accessing index %d (hartid) in array of size %d\n", hartid, num_cpus); int val = cluster_cfg[hartid]; // Out-of-bounds access printf("Value: %d\n", val); } // Simulating the fixed logic void fixed_logic(int *cluster_cfg, int num_cpus, int cpuid) { // Fix: using cpuid from for_each_online_cpu() if (cpuid < num_cpus) { printf("Accessing index %d (cpuid) in array of size %d\n", cpuid, num_cpus); int val = cluster_cfg[cpuid]; // Safe access printf("Value: %d\n", val); } } int main() { int num_online_cpus = 4; int *cluster_cfg = (int *)malloc(num_online_cpus * sizeof(int)); // Scenario: Hart IDs are non-contiguous, e.g., 0, 1, 4, 5 int hartid = 4; printf("--- Triggering Vulnerable Logic ---\n"); vulnerable_logic(cluster_cfg, num_online_cpus, hartid); printf("\n--- Triggering Fixed Logic (mapped cpuid) ---\n"); // Assuming hartid 4 maps to cpuid 2 in the topology int cpuid = 2; fixed_logic(cluster_cfg, num_online_cpus, cpuid); free(cluster_cfg); return 0; }