[PATCH] ath9k_htc: properly set MAC address and BSSID mask

[Mathy Vanhoef <mathy.vanhoef@cs.kuleuven.be>]

From: "Mathy Vanhoef" <Mathy.Vanhoef@cs.kuleuven.be>

Pick the MAC address of the first virtual interface as the new hardware MAC
address. Set BSSID mask according to this MAC address. This fixes CVE-2013-4579.

Signed-off-by: Mathy Vanhoef <Mathy.Vanhoef@cs.kuleuven.be>
---
diff --git a/drivers/net/wireless/ath/ath9k/htc_drv_main.c b/drivers/net/wireless/ath/ath9k/htc_drv_main.c
index d441045..84359c3 100644
--- a/drivers/net/wireless/ath/ath9k/htc_drv_main.c
+++ b/drivers/net/wireless/ath/ath9k/htc_drv_main.c
@@ -147,21 +147,26 @@ static void ath9k_htc_bssid_iter(void *data, u8 *mac, struct ieee80211_vif *vif)
  	struct ath9k_vif_iter_data *iter_data = data;
  	int i;
  
-	for (i = 0; i < ETH_ALEN; i++)
-		iter_data->mask[i] &= ~(iter_data->hw_macaddr[i] ^ mac[i]);
+	if (iter_data->hw_macaddr != NULL) {
+		for (i = 0; i < ETH_ALEN; i++)
+			iter_data->mask[i] &= ~(iter_data->hw_macaddr[i] ^ mac[i]);
+	} else {
+		iter_data->hw_macaddr = mac;
+	}
  }
  
-static void ath9k_htc_set_bssid_mask(struct ath9k_htc_priv *priv,
+static void ath9k_htc_set_mac_bssid_mask(struct ath9k_htc_priv *priv,
  				     struct ieee80211_vif *vif)
  {
  	struct ath_common *common = ath9k_hw_common(priv->ah);
  	struct ath9k_vif_iter_data iter_data;
  
  	/*
-	 * Use the hardware MAC address as reference, the hardware uses it
-	 * together with the BSSID mask when matching addresses.
+	 * Pick the MAC address of the first interface as the new hardware
+	 * MAC address. The hardware will use it together with the BSSID mask
+	 * when matching addresses.
  	 */
-	iter_data.hw_macaddr = common->macaddr;
+	iter_data.hw_macaddr = NULL;
  	memset(&iter_data.mask, 0xff, ETH_ALEN);
  
  	if (vif)
@@ -173,6 +178,10 @@ static void ath9k_htc_set_bssid_mask(struct ath9k_htc_priv *priv,
  		ath9k_htc_bssid_iter, &iter_data);
  
  	memcpy(common->bssidmask, iter_data.mask, ETH_ALEN);
+
+	if (iter_data.hw_macaddr)
+		memcpy(common->macaddr, iter_data.hw_macaddr, ETH_ALEN);
+
  	ath_hw_setbssidmask(common);
  }
  
@@ -1083,7 +1092,7 @@ static int ath9k_htc_add_interface(struct ieee80211_hw *hw,
  		goto out;
  	}
  
-	ath9k_htc_set_bssid_mask(priv, vif);
+	ath9k_htc_set_mac_bssid_mask(priv, vif);
  
  	priv->vif_slot |= (1 << avp->index);
  	priv->nvifs++;
@@ -1148,7 +1157,7 @@ static void ath9k_htc_remove_interface(struct ieee80211_hw *hw,
  
  	ath9k_htc_set_opmode(priv);
  
-	ath9k_htc_set_bssid_mask(priv, vif);
+	ath9k_htc_set_mac_bssid_mask(priv, vif);
  
  	/*
  	 * Stop ANI only if there are no associated station interfaces.
diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
index b6aad69..99ab0aa 100644
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -885,8 +885,9 @@ void ath9k_calculate_iter_data(struct ieee80211_hw *hw,
  	struct ath_common *common = ath9k_hw_common(ah);
  
  	/*
-	 * Use the hardware MAC address as reference, the hardware uses it
-	 * together with the BSSID mask when matching addresses.
+	 * Pick the MAC address of the first interface as the new hardware
+	 * MAC address. The hardware will use it together with the BSSID mask
+	 * when matching addresses.
  	 */
  	memset(iter_data, 0, sizeof(*iter_data));
  	memset(&iter_data->mask, 0xff, ETH_ALEN);


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