Using the secure function snprintf

[FoolStrong]

In the source code, a large number of functions use sprintf to process strings, which may cause overflow risks. You are advised to use snprintf to ensure that strings no out of the bounds.

[FoolStrong]

for example

static void *add_dax_dev(void *parent, int id, const char *daxdev_base)
{
	 const char *devname = devpath_to_devname(daxdev_base);
	 char *path = calloc(1, strlen(daxdev_base) + 100);
	 struct daxctl_region *region = parent;
	 struct daxctl_ctx *ctx = region->ctx;
	 struct daxctl_dev *dev, *dev_dup;
	 char buf[SYSFS_ATTR_SIZE];
	 struct stat st;

	if (!path)
		return NULL;
	dbg(ctx, "%s: base: \'%s\'\n", __func__, daxdev_base);

	dev = calloc(1, sizeof(*dev));
	if (!dev)
		goto err_dev;
	dev->id = id;
	dev->region = region;

	sprintf(path, "/dev/%s", devname);
	if (stat(path, &st) < 0)
		goto err_read;
	dev->major = major(st.st_rdev);
	dev->minor = minor(st.st_rdev);

	sprintf(path, "%s/resource", daxdev_base);
	if (sysfs_read_attr(ctx, path, buf) == 0)
		dev->resource = strtoull(buf, NULL, 0);
	else
		dev->resource = iomem_get_dev_resource(ctx, daxdev_base);

	sprintf(path, "%s/size", daxdev_base);
	if (sysfs_read_attr(ctx, path, buf) < 0)
		goto err_read;
	dev->size = strtoull(buf, NULL, 0);

	/* Device align attribute is only available in v5.10 or up */
	sprintf(path, "%s/align", daxdev_base);
	if (!sysfs_read_attr(ctx, path, buf))
		dev->align = strtoull(buf, NULL, 0);
	else
		dev->align = 0;

	dev->dev_path = strdup(daxdev_base);
	if (!dev->dev_path)
		goto err_read;

	dev->dev_buf = calloc(1, strlen(daxdev_base) + 50);
	if (!dev->dev_buf)
		goto err_read;
	dev->buf_len = strlen(daxdev_base) + 50;

	sprintf(path, "%s/target_node", daxdev_base);
	if (sysfs_read_attr(ctx, path, buf) == 0)
		dev->target_node = strtol(buf, NULL, 0);
	else
		dev->target_node = -1;

	daxctl_dev_foreach(region, dev_dup)
		if (dev_dup->id == dev->id) {
			free_dev(dev, NULL);
			free(path);
			return dev_dup;
		}
	dev->num_mappings = -1;
	list_head_init(&dev->mappings);
	list_add(&region->devices, &dev->list);
	free(path);
	return dev;
 err_read:
	free(dev->dev_buf);
	free(dev->dev_path);
	free(dev);
 err_dev:
	free(path);
	return NULL;
}

[FoolStrong]

ok