static bool ldm_validate_tocblocks(struct parsed_partitions *state,
				   unsigned long base, struct ldmdb *ldb)
{
	static const int off[4] = { OFF_TOCB1, OFF_TOCB2, OFF_TOCB3, OFF_TOCB4};
	struct tocblock *tb[4];
	struct privhead *ph;
	Sector sect;
	u8 *data;
	int i, nr_tbs;
	bool result = false;

	BUG_ON(!state || !ldb);
	ph = &ldb->ph;
	tb[0] = &ldb->toc;
	tb[1] = kmalloc(sizeof(*tb[1]) * 3, GFP_KERNEL);
	if (!tb[1]) {
		ldm_crit("Out of memory.");
		goto err;
	}
	tb[2] = (struct tocblock*)((u8*)tb[1] + sizeof(*tb[1]));
	tb[3] = (struct tocblock*)((u8*)tb[2] + sizeof(*tb[2]));
	/*
	 * Try to read and parse all four TOCBLOCKs.
	 *
	 * Windows Vista LDM v2.12 does not always have all four TOCBLOCKs so
	 * skip any that fail as long as we get at least one valid TOCBLOCK.
	 */
	for (nr_tbs = i = 0; i < 4; i++) {
		data = read_part_sector(state, base + off[i], &sect);
		if (!data) {
			ldm_error("Disk read failed for TOCBLOCK %d.", i);
			continue;
		}
		if (ldm_parse_tocblock(data, tb[nr_tbs]))
			nr_tbs++;
		put_dev_sector(sect);
	}
	if (!nr_tbs) {
		ldm_crit("Failed to find a valid TOCBLOCK.");
		goto err;
	}
	/* Range check the TOCBLOCK against a privhead. */
	if (((tb[0]->bitmap1_start + tb[0]->bitmap1_size) > ph->config_size) ||
			((tb[0]->bitmap2_start + tb[0]->bitmap2_size) >
			ph->config_size)) {
		ldm_crit("The bitmaps are out of range.  Giving up.");
		goto err;
	}
	/* Compare all loaded TOCBLOCKs. */
	for (i = 1; i < nr_tbs; i++) {
		if (!ldm_compare_tocblocks(tb[0], tb[i])) {
			ldm_crit("TOCBLOCKs 0 and %d do not match.", i);
			goto err;
		}
	}
	ldm_debug("Validated %d TOCBLOCKs successfully.", nr_tbs);
	result = true;
err:
	kfree(tb[1]);
	return result;
}

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.