CVE-2026-31689 Linux内核EDAC模块错误路径排序漏洞

/* * Conceptual PoC for CVE-2026-31689 * This C code simulates the vulnerable logic flow in the Linux kernel EDAC subsystem. * Triggering the actual crash requires a specific environment (kernel compilation, hardware). */ #include <stdio.h> #include <stdlib.h> // Simulating kernel structures struct kobject { const char *name; int initialized; }; struct device { struct kobject kobj; void (*release)(struct device *dev); }; struct mem_ctl_info { struct device dev; void *pvt_info; }; // Helper to simulate put_device -> kobject_put void kobject_put(struct kobject *kobj) { if (!kobj->initialized) { printf("[VULNERABILITY TRIGGERED] kobject: '(null)': is not initialized, yet kobject_put() is being called.\n"); // In real kernel, this causes a panic/warning } else { printf("kobject released safely.\n"); } } void put_device(struct device *dev) { if (dev && dev->release) dev->release(dev); kobject_put(&dev->kobj); } void device_initialize(struct device *dev) { dev->kobj.initialized = 1; printf("Device initialized.\n"); } // The Vulnerable Function (edac_mc_alloc logic) struct mem_ctl_info* edac_mc_alloc_vulnerable() { struct mem_ctl_info *mci = (struct mem_ctl_info*)malloc(sizeof(struct mem_ctl_info)); if (!mci) return NULL; // 1. Attempt to allocate private info mci->pvt_info = malloc(1024); // Simulate allocation if (!mci->pvt_info) { // 2. Error path reached printf("Allocation failed, entering error path...\n"); // 3. VULNERABILITY: put_device is called BEFORE device_initialize put_device(&mci->dev); free(mci); return NULL; } // This happens AFTER the check in the vulnerable version device_initialize(&mci->dev); return mci; } int main() { printf("Simulating CVE-2026-31689...\n"); // Force allocation failure by passing NULL or simulating OOM // For this demo, we manually trigger the failure path logic struct mem_ctl_info *mci = (struct mem_ctl_info*)malloc(sizeof(struct mem_ctl_info)); mci->pvt_info = NULL; // Simulate alloc failure if (!mci->pvt_info) { put_device(&mci->dev); // Trigger the bug } free(mci); return 0; }