mac80211: linearize SKBs as needed for crypto

Not linearizing every SKB will help actually pass
non-linear SKBs all the way up when on an encrypted
connection. For now, linearize TKIP completely as
it is lower performance and I don't quite grok all
the details.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 8 insertions, 3 deletions

diff --git a/net/mac80211/wep.c b/net/mac80211/wep.c
index 5cd87ba11bb7..7aa31bbfaa3b 100644
--- a/net/mac80211/wep.c
+++ b/net/mac80211/wep.c
@@ -284,22 +284,27 @@ ieee80211_crypto_wep_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 *)skb->data;
+        __le16 fc = hdr->frame_control;
 
-        if (!ieee80211_is_data(hdr->frame_control) &&
-            !ieee80211_is_auth(hdr->frame_control))
+        if (!ieee80211_is_data(fc) && !ieee80211_is_auth(fc))
                 return RX_CONTINUE;
 
         if (!(status->flag & RX_FLAG_DECRYPTED)) {
+                if (skb_linearize(rx->skb))
+                        return RX_DROP_UNUSABLE;
                 if (rx->sta && ieee80211_wep_is_weak_iv(rx->skb, rx->key))
                         rx->sta->wep_weak_iv_count++;
                 if (ieee80211_wep_decrypt(rx->local, rx->skb, rx->key))
                         return RX_DROP_UNUSABLE;
         } else if (!(status->flag & RX_FLAG_IV_STRIPPED)) {
+                if (!pskb_may_pull(rx->skb, ieee80211_hdrlen(fc) + WEP_IV_LEN))
+                        return RX_DROP_UNUSABLE;
                 if (rx->sta && ieee80211_wep_is_weak_iv(rx->skb, rx->key))
                         rx->sta->wep_weak_iv_count++;
                 ieee80211_wep_remove_iv(rx->local, rx->skb, rx->key);
                 /* remove ICV */
-                skb_trim(rx->skb, rx->skb->len - WEP_ICV_LEN);
+                if (pskb_trim(rx->skb, rx->skb->len - WEP_ICV_LEN))
+                        return RX_DROP_UNUSABLE;
         }
 
         return RX_CONTINUE;