On Wed, 2010-04-07 at 17:26 +0800, Johannes Berg wrote:
> From: Johannes Berg <johannes.berg@xxxxxxxxx>
>
> WEP crypto was broken, but upon finding the problem
> it is evident that other things were broken by the
> paged RX patch as well.
>
> To fix it, for now move the linearising in front.
> This means that we linearise all frames, which is
> not at all what we want, but at least it fixes the
> problem for now.
>
> Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
> Acked-by: Zhu Yi <yi.zhu@xxxxxxxxx>
I thought it over. We don't need to handle nonlinear skb in
ieee80211_get_mmie_keyidx(), because we only need to touch fields out of
802.11 header for management frames, and we have already skb_linearize
all management frames before. Now we just need to handle WEP IV
correctly. How about this patch?
Signed-off-by: Zhu Yi <yi.zhu@xxxxxxxxx>
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 14366d4..a8f11f6 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -894,6 +894,7 @@ ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
rx->key = key;
return RX_CONTINUE;
} else {
+ u8 keyid;
/*
* The device doesn't give us the IV so we won't be
* able to look up the key. That's ok though, we
@@ -916,7 +917,8 @@ ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
* no need to call ieee80211_wep_get_keyidx,
* it verifies a bunch of things we've done already
*/
- keyidx = rx->skb->data[hdrlen + 3] >> 6;
+ skb_copy_bits(rx->skb, hdrlen + 3, &keyid, 1);
+ keyidx = keyid >> 6;
rx->key = rcu_dereference(rx->sdata->keys[keyidx]);
@@ -937,9 +939,6 @@ ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
return RX_DROP_MONITOR;
}
- if (skb_linearize(rx->skb))
- return RX_DROP_UNUSABLE;
-
/* Check for weak IVs if possible */
if (rx->sta && rx->key->conf.alg == ALG_WEP &&
ieee80211_is_data(hdr->frame_control) &&
@@ -948,6 +947,9 @@ ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
ieee80211_wep_is_weak_iv(rx->skb, rx->key))
rx->sta->wep_weak_iv_count++;
+ if (skb_linearize(rx->skb))
+ return RX_DROP_UNUSABLE;
+
switch (rx->key->conf.alg) {
case ALG_WEP:
result = ieee80211_crypto_wep_decrypt(rx);
--
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