net: bmac: Fix read of MAC address from ROM

[ Upstream commit ef01cee2 ]

In bmac_get_station_address, We're reading two bytes at a time from ROM,
but we do that six times, resulting in 12 bytes of read & writes. This
means we will write off the end of the six-byte destination buffer.

This change fixes the for-loop to only read/write six bytes.

Based on a proposed fix from Finn Thain <fthain@telegraphics.com.au>.
Signed-off-by: NJeremy Kerr <jk@ozlabs.org>
Reported-by: NStan Johnson <userm57@yahoo.com>
Tested-by: NStan Johnson <userm57@yahoo.com>
Reported-by: NFinn Thain <fthain@telegraphics.com.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

drivers/net/ethernet/apple/bmac.c

@@ -1181,7 +1181,7 @@ bmac_get_station_address(struct net_device *dev, unsigned char *ea)
 	int i;
 	unsigned short data;
 
-	for (i = 0; i < 6; i++)
+	for (i = 0; i < 3; i++)
 		{
 			reset_and_select_srom(dev);
 			data = read_srom(dev, i + EnetAddressOffset/2, SROMAddressBits);