[patch 44/45] cfg80211: fix incorrect assumption on last_request for 11d

[Chris Wright]

-stable review patch.  If anyone has any objections, please let us know.
---------------------

From: Luis R. Rodriguez <lrodriguez@xxxxxxxxxxx>

upstream commit: cc0b6fe88e99096868bdbacbf486c97299533b5a

The incorrect assumption is the last regulatory request
(last_request) is always a country IE when processing
country IEs. Although this is true 99% of the time the
first time this happens this could not be true.

This fixes an oops in the branch check for the last_request
when accessing drv_last_ie. The access was done under the
assumption the struct won't be null.

Note to stable: to port to 29 replace as follows, only 29 has
country IE code:

s|NL80211_REGDOM_SET_BY_COUNTRY_IE|REGDOM_SET_BY_COUNTRY_IE

Cc: stable@xxxxxxxxxx
Reported-by: Quentin Armitage <Quentin@xxxxxxxxxxxxxxx>
Signed-off-by: Luis R. Rodriguez <lrodriguez@xxxxxxxxxxx>
Signed-off-by: John W. Linville <linville@xxxxxxxxxxxxx>
[chrisw: backport to 2.6.29]
Signed-off-by: Chris Wright <chrisw@xxxxxxxxxxxx>
---
 net/wireless/reg.c |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

--- a/net/wireless/reg.c
+++ b/net/wireless/reg.c
@@ -1083,6 +1083,8 @@ EXPORT_SYMBOL(regulatory_hint);
 static bool reg_same_country_ie_hint(struct wiphy *wiphy,
 			u32 country_ie_checksum)
 {
+	if (unlikely(last_request->initiator != REGDOM_SET_BY_COUNTRY_IE))
+		return false;
 	if (!last_request->wiphy)
 		return false;
 	if (likely(last_request->wiphy != wiphy))
@@ -1133,7 +1135,9 @@ void regulatory_hint_11d(struct wiphy *w
 	/* We will run this for *every* beacon processed for the BSSID, so
 	 * we optimize an early check to exit out early if we don't have to
 	 * do anything */
-	if (likely(last_request->wiphy)) {
+	if (likely(last_request->initiator ==
+	    REGDOM_SET_BY_COUNTRY_IE &&
+	    likely(last_request->wiphy))) {
 		struct cfg80211_registered_device *drv_last_ie;
 
 		drv_last_ie = wiphy_to_dev(last_request->wiphy);

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