2012-01-16 13:17:10

by Yoni Divinsky

[permalink] [raw]
Subject: [PATCH v2] 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 <[email protected]>
---
net/mac80211/tx.c | 10 +---------
net/mac80211/wpa.c | 19 +++++++++++++++++++
net/mac80211/wpa.h | 2 ++
3 files changed, 22 insertions(+), 9 deletions(-)

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index edcd1c7..e05667c 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 93aab07..89be1ee 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 baba060..07e33f8 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 */
--
1.7.0.4