void __check_sit_bitmap(struct f2fs_sb_info *sbi,
				block_t start, block_t end)
{
#ifdef CONFIG_F2FS_CHECK_FS
	struct seg_entry *sentry;
	unsigned int segno;
	block_t blk = start;
	unsigned long offset, size, max_blocks = sbi->blocks_per_seg;
	unsigned long *map;

	while (blk < end) {
		segno = GET_SEGNO(sbi, blk);
		sentry = get_seg_entry(sbi, segno);
		offset = GET_BLKOFF_FROM_SEG0(sbi, blk);

		if (end < START_BLOCK(sbi, segno + 1))
			size = GET_BLKOFF_FROM_SEG0(sbi, end);
		else
			size = max_blocks;
		map = (unsigned long *)(sentry->cur_valid_map);
		offset = __find_rev_next_bit(map, size, offset);
		f2fs_bug_on(sbi, offset != size);
		blk = START_BLOCK(sbi, segno + 1);
	}
#endif
}

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.