CVE-2026-31475: Linux内核sma1307驱动双重释放漏洞

/* * Conceptual Proof of Concept for CVE-2026-31475 * This snippet demonstrates the vulnerable logic flow in the driver. * Actual exploitation requires specific hardware (sma1307) and triggering conditions. */ #include <linux/slab.h> #include <linux/device.h> // Simulated vulnerable function structure void vulnerable_logic(struct device *dev) { struct mode_set *entries; int i; // devm_kzalloc is used here (device managed) entries = devm_kzalloc(dev, sizeof(*entries) * 10, GFP_KERNEL); if (!entries) return; // Simulate a condition that triggers the error path after allocation if (some_error_condition()) { // VULNERABILITY: Manually freeing memory managed by devres for (i = 0; i < 10; i++) { if (entries[i].data) kfree(entries[i].data); // Double free risk here } kfree(entries); // Double free risk here return; } // ... normal operation ... } /* * Fix: Remove the manual kfree loop. The devres subsystem will handle * cleanup automatically when the device is detached. */