static struct inode *ext4_alloc_inode(struct super_block *sb)
{
	struct ext4_inode_info *ei;

	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
	if (!ei)
		return NULL;

	ei->vfs_inode.i_version = 1;
	spin_lock_init(&ei->i_raw_lock);
	INIT_LIST_HEAD(&ei->i_prealloc_list);
	spin_lock_init(&ei->i_prealloc_lock);
	ext4_es_init_tree(&ei->i_es_tree);
	rwlock_init(&ei->i_es_lock);
	INIT_LIST_HEAD(&ei->i_es_list);
	ei->i_es_all_nr = 0;
	ei->i_es_shk_nr = 0;
	ei->i_es_shrink_lblk = 0;
	ei->i_reserved_data_blocks = 0;
	ei->i_reserved_meta_blocks = 0;
	ei->i_allocated_meta_blocks = 0;
	ei->i_da_metadata_calc_len = 0;
	ei->i_da_metadata_calc_last_lblock = 0;
	spin_lock_init(&(ei->i_block_reservation_lock));
#ifdef CONFIG_QUOTA
	ei->i_reserved_quota = 0;
	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
#endif
	ei->jinode = NULL;
	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
	spin_lock_init(&ei->i_completed_io_lock);
	ei->i_sync_tid = 0;
	ei->i_datasync_tid = 0;
	atomic_set(&ei->i_unwritten, 0);
	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
	return &ei->vfs_inode;
}

The product reads data past the end, or before the beginning, of the intended buffer.