static int isofs_get_block(struct inode *inode, sector_t iblock,
		    struct buffer_head *bh_result, int create)
{
	int ret;

	if (create) {
		printk(KERN_DEBUG "%s: Kernel tries to allocate a block\n", __func__);
		return -EROFS;
	}

	ret = isofs_get_blocks(inode, iblock, &bh_result, 1);
	return ret < 0 ? ret : 0;
}

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.