pch_gbe: memory corruption calling pch_gbe_validate_option()

pch_gbe_validate_option() modifies 32 bits of memory but we pass
&hw->phy.autoneg_advertised which only has 16 bits and &hw->mac.fc
which only has 8 bits.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_param.c

@@ -321,10 +321,10 @@ static void pch_gbe_check_copper_options(struct pch_gbe_adapter *adapter)
 			pr_debug("AutoNeg specified along with Speed or Duplex, AutoNeg parameter ignored\n");
 			hw->phy.autoneg_advertised = opt.def;
 		} else {
-			hw->phy.autoneg_advertised = AutoNeg;
-			pch_gbe_validate_option(
-				(int *)(&hw->phy.autoneg_advertised),
-				&opt, adapter);
+			int tmp = AutoNeg;
+
+			pch_gbe_validate_option(&tmp, &opt, adapter);
+			hw->phy.autoneg_advertised = tmp;
 		}
 	}
 
@@ -495,9 +495,10 @@ void pch_gbe_check_options(struct pch_gbe_adapter *adapter)
 			.arg  = { .l = { .nr = (int)ARRAY_SIZE(fc_list),
 					 .p = fc_list } }
 		};
-		hw->mac.fc = FlowControl;
-		pch_gbe_validate_option((int *)(&hw->mac.fc),
-						&opt, adapter);
+		int tmp = FlowControl;
+
+		pch_gbe_validate_option(&tmp, &opt, adapter);
+		hw->mac.fc = tmp;
 	}
 
 	pch_gbe_check_copper_options(adapter);