ath9k: reject invalid antenna mask configurations

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@32507 3c298f89-4303-0410-b956-a3cf2f4a3e73

package/mac80211/patches/561-ath9k_antenna_mask_validate.patch

@@ -0,0 +1,28 @@
+--- a/drivers/net/wireless/ath/ath9k/main.c
++++ b/drivers/net/wireless/ath/ath9k/main.c
+@@ -1929,12 +1929,24 @@ static u32 fill_chainmask(u32 cap, u32 n
+ 	return filled;
+ }
+
++static bool validate_antenna_mask(u32 val)
++{
++	switch (val & 0x7) {
++	case 0x1:
++	case 0x3:
++	case 0x7:
++		return true;
++	default:
++		return false;
++	}
++}
++
+ static int ath9k_set_antenna(struct ieee80211_hw *hw, u32 tx_ant, u32 rx_ant)
+ {
+ 	struct ath_softc *sc = hw->priv;
+ 	struct ath_hw *ah = sc->sc_ah;
+
+-	if (!rx_ant || !tx_ant)
++	if (!validate_antenna_mask(rx_ant) || !validate_antenna_mask(tx_ant))
+ 		return -EINVAL;
+
+ 	sc->ant_rx = rx_ant;