mac80211: fix tx->skb NULL pointer dereference

In function ieee80211_tx_h_encrypt the var info was
initialized from tx->skb, since the fucntion
is called after the function ieee80211_tx_h_fragment
tx->skb is not valid anymore.

Signed-off-by: Yoni Divinsky <yoni.divinsky@ti.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

3 files changed, 22 insertions, 9 deletions

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index edcd1c7ab83f..e05667cd5e76 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -1001,8 +1001,6 @@ ieee80211_tx_h_stats(struct ieee80211_tx_data *tx)
 static ieee80211_tx_result debug_noinline
 ieee80211_tx_h_encrypt(struct ieee80211_tx_data *tx)
 {
-        struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
-
         if (!tx->key)
                 return TX_CONTINUE;
 
@@ -1017,13 +1015,7 @@ ieee80211_tx_h_encrypt(struct ieee80211_tx_data *tx)
         case WLAN_CIPHER_SUITE_AES_CMAC:
                 return ieee80211_crypto_aes_cmac_encrypt(tx);
         default:
-                /* handle hw-only algorithm */
-                if (info->control.hw_key) {
-                        ieee80211_tx_set_protected(tx);
-                        return TX_CONTINUE;
-                }
-                break;
-
+                return ieee80211_crypto_hw_encrypt(tx);
         }
 
         return TX_DROP;
diff --git a/net/mac80211/wpa.c b/net/mac80211/wpa.c
index 422b79851ec5..b758350919ff 100644
--- a/net/mac80211/wpa.c
+++ b/net/mac80211/wpa.c
@@ -643,3 +643,22 @@ ieee80211_crypto_aes_cmac_decrypt(struct ieee80211_rx_data *rx)
 
         return RX_CONTINUE;
 }
+
+ieee80211_tx_result
+ieee80211_crypto_hw_encrypt(struct ieee80211_tx_data *tx)
+{
+        struct sk_buff *skb;
+        struct ieee80211_tx_info *info = NULL;
+
+        skb_queue_walk(&tx->skbs, skb) {
+                info  = IEEE80211_SKB_CB(skb);
+
+                /* handle hw-only algorithm */
+                if (!info->control.hw_key)
+                        return TX_DROP;
+        }
+
+        ieee80211_tx_set_protected(tx);
+
+        return TX_CONTINUE;
+}
diff --git a/net/mac80211/wpa.h b/net/mac80211/wpa.h
index baba0608313e..07e33f899c71 100644
--- a/net/mac80211/wpa.h
+++ b/net/mac80211/wpa.h
@@ -32,5 +32,7 @@ ieee80211_tx_result
 ieee80211_crypto_aes_cmac_encrypt(struct ieee80211_tx_data *tx);
 ieee80211_rx_result
 ieee80211_crypto_aes_cmac_decrypt(struct ieee80211_rx_data *rx);
+ieee80211_tx_result
+ieee80211_crypto_hw_encrypt(struct ieee80211_tx_data *tx);
 
 #endif /* WPA_H */