commit 683d41ae6755e6ae297ec09603c229795ab9566e
author Simon Wunderlich <simon.wunderlich@s2003.tu-chemnitz.de> Wed Jan 23 15:15:57 2013 +0100
committer Johannes Berg <johannes.berg@intel.com> Thu Jan 24 16:05:30 2013 +0100
tree 528f940800257f790c98cac635af0f622e0c1a1c
parent f68d776a04bfcebc426f605c4440ffe38c583a4b

cfg80211: fix channel check in cfg80211_can_use_iftype_chan

In commit "cfg80211: check radar interface combinations" a regression
was introduced which might lead to NULL dereference if the argument
chan = NULL, which might happen in IBSS/wext case (and probably
others).

Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/wireless/util.c

diff --git a/net/wireless/util.c b/net/wireless/util.c
index 1c2795d..d7873c7 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -1212,7 +1212,8 @@
 	case NL80211_IFTYPE_MESH_POINT:
 	case NL80211_IFTYPE_P2P_GO:
 	case NL80211_IFTYPE_WDS:
-		radar_required = !!(chan->flags & IEEE80211_CHAN_RADAR);
+		radar_required = !!(chan &&
+				    (chan->flags & IEEE80211_CHAN_RADAR));
 		break;
 	case NL80211_IFTYPE_P2P_CLIENT:
 	case NL80211_IFTYPE_STATION: