static int tg3_nvram_write_block(struct tg3 *tp, u32 offset, u32 len, u8 *buf)
{
	int ret;

	if (tg3_flag(tp, EEPROM_WRITE_PROT)) {
		tw32_f(GRC_LOCAL_CTRL, tp->grc_local_ctrl &
		       ~GRC_LCLCTRL_GPIO_OUTPUT1);
		udelay(40);
	}

	if (!tg3_flag(tp, NVRAM)) {
		ret = tg3_nvram_write_block_using_eeprom(tp, offset, len, buf);
	} else {
		u32 grc_mode;

		ret = tg3_nvram_lock(tp);
		if (ret)
			return ret;

		tg3_enable_nvram_access(tp);
		if (tg3_flag(tp, 5750_PLUS) && !tg3_flag(tp, PROTECTED_NVRAM))
			tw32(NVRAM_WRITE1, 0x406);

		grc_mode = tr32(GRC_MODE);
		tw32(GRC_MODE, grc_mode | GRC_MODE_NVRAM_WR_ENABLE);

		if (tg3_flag(tp, NVRAM_BUFFERED) || !tg3_flag(tp, FLASH)) {
			ret = tg3_nvram_write_block_buffered(tp, offset, len,
				buf);
		} else {
			ret = tg3_nvram_write_block_unbuffered(tp, offset, len,
				buf);
		}

		grc_mode = tr32(GRC_MODE);
		tw32(GRC_MODE, grc_mode & ~GRC_MODE_NVRAM_WR_ENABLE);

		tg3_disable_nvram_access(tp);
		tg3_nvram_unlock(tp);
	}

	if (tg3_flag(tp, EEPROM_WRITE_PROT)) {
		tw32_f(GRC_LOCAL_CTRL, tp->grc_local_ctrl);
		udelay(40);
	}

	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.