static int tg3_set_eeprom(struct net_device *dev, struct ethtool_eeprom *eeprom, u8 *data)
{
	struct tg3 *tp = netdev_priv(dev);
	int ret;
	u32 offset, len, b_offset, odd_len;
	u8 *buf;
	__be32 start, end;

	if (tp->phy_flags & TG3_PHYFLG_IS_LOW_POWER)
		return -EAGAIN;

	if (tg3_flag(tp, NO_NVRAM) ||
	    eeprom->magic != TG3_EEPROM_MAGIC)
		return -EINVAL;

	offset = eeprom->offset;
	len = eeprom->len;

	if ((b_offset = (offset & 3))) {
		/* adjustments to start on required 4 byte boundary */
		ret = tg3_nvram_read_be32(tp, offset-b_offset, &start);
		if (ret)
			return ret;
		len += b_offset;
		offset &= ~3;
		if (len < 4)
			len = 4;
	}

	odd_len = 0;
	if (len & 3) {
		/* adjustments to end on required 4 byte boundary */
		odd_len = 1;
		len = (len + 3) & ~3;
		ret = tg3_nvram_read_be32(tp, offset+len-4, &end);
		if (ret)
			return ret;
	}

	buf = data;
	if (b_offset || odd_len) {
		buf = kmalloc(len, GFP_KERNEL);
		if (!buf)
			return -ENOMEM;
		if (b_offset)
			memcpy(buf, &start, 4);
		if (odd_len)
			memcpy(buf+len-4, &end, 4);
		memcpy(buf + b_offset, data, eeprom->len);
	}

	ret = tg3_nvram_write_block(tp, offset, len, buf);

	if (buf != data)
		kfree(buf);

	return ret;
}

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.