Smart card reader causes libusb crash

Insert and unplug the smart card reader on windows platform causes libusb crash. releated issues #285

static char *parse_device_interface_path(const char *interface_path)
{
	char *device_id, *guid_start;
	unsigned int i, len;

	len = safe_strlen(interface_path);
	if (len < 4) {
		return NULL;
	}

	// Microsoft indiscriminatly uses '\\?\', '\\.\', '##?#" or "##.#" for root prefixes.
	if (((interface_path[0] == '\\') && (interface_path[1] == '\\') && (interface_path[3] == '\\')) ||
		((interface_path[0] == '#') && (interface_path[1] == '#') && (interface_path[3] == '#'))) {
		interface_path += 4;
		len -= 4;
	}

	guid_start = strchr(interface_path, '{');
	if (guid_start != NULL) {
		len = (guid_start - interface_path) - 1; // One more for separator
	}

	if (len <= 0) {
		usbi_err(NULL, "program assertion failed: invalid device interface path");
		return NULL;
	}

	device_id = calloc(len + 1, 1); // One additional for NULL term.
	if (device_id == NULL) {
		return NULL;
	}
	strncat(device_id, interface_path, len);

	// Now convert to uppercase and replace '#' with '\'
	for (i = 0; i < len; i++) {
		device_id[i] = (char)toupper((int)device_id[i]);
		if (device_id[i] == '#')
			device_id[i] = '\\';
	}

	return device_id;
}

The unsigned int len cause the len Value cannot be negative and then Cause the code if(len<=0) not to be executed when len should be -1;

device_id[i] emit Array out of bounds exception

Just need to modify unsigned int len to int len

[danielmain]

Having the same Issue. Thank you @xdimh now can I patch it in my project.

Dont you @xdimh want to create a PR so that the node-usb Team can apply it faster?

[thegecko]

Excellent, closing. Please re open this if required.