We delay the skb linearising in ieee80211_rx_h_decrypt so that
frames do not require software decryption are not linearized. We
are safe to do this because ieee80211_get_mmie_keyidx() only
requires to touch nonlinear data for management frames, which are
already linearized before getting here.
Cc: Johannes Berg <johannes.berg@xxxxxxxxx>
Signed-off-by: Zhu Yi <yi.zhu@xxxxxxxxx>
---
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index c0ad7e8..052cee0 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -820,7 +820,7 @@ ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
{
struct sk_buff *skb = rx->skb;
struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
- struct ieee80211_hdr *hdr;
+ struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
int keyidx;
int hdrlen;
ieee80211_rx_result result = RX_DROP_UNUSABLE;
@@ -861,11 +861,6 @@ ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
if (!(rx->flags & IEEE80211_RX_RA_MATCH))
return RX_CONTINUE;
- if (skb_linearize(rx->skb))
- return RX_DROP_UNUSABLE;
-
- hdr = (struct ieee80211_hdr *)skb->data;
-
/* start without a key */
rx->key = NULL;
@@ -906,6 +901,7 @@ 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
@@ -928,7 +924,8 @@ 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]);
@@ -949,6 +946,11 @@ ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
return RX_DROP_MONITOR;
}
+ if (skb_linearize(rx->skb))
+ return RX_DROP_UNUSABLE;
+
+ hdr = (struct ieee80211_hdr *)rx->skb->data;
+
/* Check for weak IVs if possible */
if (rx->sta && rx->key->conf.alg == ALG_WEP &&
ieee80211_is_data(hdr->frame_control) &&
--
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