int f2fs_get_block(struct dnode_of_data *dn, pgoff_t index)
{
	struct extent_info ei;
	struct inode *inode = dn->inode;

	if (f2fs_lookup_extent_cache(inode, index, &ei)) {
		dn->data_blkaddr = ei.blk + index - ei.fofs;
		return 0;
	}

	return f2fs_reserve_block(dn, index);
}

The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.