mac80211: fix HT information element parsing

There's no checking that the HT IEs are of the right length
which can be used by an attacker to cause an out-of-bounds
access by sending a too short HT information/capability IE.
Fix it by simply pretending those IEs didn't exist when too
short.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 8025b29..156e42a 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -816,8 +816,8 @@
 	u8 *ext_supp_rates;
 	u8 *wmm_info;
 	u8 *wmm_param;
-	u8 *ht_cap_elem;
-	u8 *ht_info_elem;
+	struct ieee80211_ht_cap *ht_cap_elem;
+	struct ieee80211_ht_addt_info *ht_info_elem;
 	u8 *mesh_config;
 	u8 *mesh_id;
 	u8 *peer_link;
@@ -844,8 +844,6 @@
 	u8 ext_supp_rates_len;
 	u8 wmm_info_len;
 	u8 wmm_param_len;
-	u8 ht_cap_elem_len;
-	u8 ht_info_elem_len;
 	u8 mesh_config_len;
 	u8 mesh_id_len;
 	u8 peer_link_len;