diff --git a/drivers/net/e1000e/ethtool.c b/drivers/net/e1000e/ethtool.c
index b6243ca..0aa50c2 100644
--- a/drivers/net/e1000e/ethtool.c
+++ b/drivers/net/e1000e/ethtool.c
@@ -535,7 +535,8 @@
 
 	if (ret_val) {
 		/* a read error occurred, throw away the result */
-		memset(eeprom_buff, 0xff, sizeof(eeprom_buff));
+		memset(eeprom_buff, 0xff, sizeof(u16) *
+		       (last_word - first_word + 1));
 	} else {
 		/* Device's eeprom is always little-endian, word addressable */
 		for (i = 0; i < last_word - first_word + 1; i++)