cfg80211: hold reg_mutex when updating regulatory

The function wiphy_update_regulatory() uses the static variable
last_request and thus needs to be called with reg_mutex held.
This is the case for all users in reg.c, but the function was
exported for use by wiphy_register(), from where it is called
without the lock being held.

Fix this by making wiphy_update_regulatory() private and introducing
regulatory_update() as a wrapper that acquires and holds the lock.

Signed-off-by: Sven Neumann <s.neumann@raumfeld.com>
Cc: John W. Linville <linville@tuxdriver.com>
Cc: Luis R. Rodriguez <mcgrof@gmail.com>
Cc: Daniel Mack <daniel@zonque.org>
Cc: linux-wireless@vger.kernel.org
Acked-by:  Luis R. Rodriguez <mcgrof@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

4 files changed, 18 insertions, 5 deletions

diff --git a/net/wireless/core.c b/net/wireless/core.c
index 645437cfc464..44cbebac25e0 100644
--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -582,7 +582,7 @@ int wiphy_register(struct wiphy *wiphy)
         }
 
         /* set up regulatory info */
-        wiphy_update_regulatory(wiphy, NL80211_REGDOM_SET_BY_CORE);
+        regulatory_update(wiphy, NL80211_REGDOM_SET_BY_CORE);
 
         list_add_rcu(&rdev->list, &cfg80211_rdev_list);
         cfg80211_rdev_list_generation++;
diff --git a/net/wireless/core.h b/net/wireless/core.h
index 8672e028022f..796a4bdf8b0d 100644
--- a/net/wireless/core.h
+++ b/net/wireless/core.h
@@ -279,8 +279,6 @@ extern int cfg80211_dev_rename(struct cfg80211_registered_device *rdev,
                                char *newname);
 
 void ieee80211_set_bitrate_flags(struct wiphy *wiphy);
-void wiphy_update_regulatory(struct wiphy *wiphy,
-                             enum nl80211_reg_initiator setby);
 
 void cfg80211_bss_expire(struct cfg80211_registered_device *dev);
 void cfg80211_bss_age(struct cfg80211_registered_device *dev,
diff --git a/net/wireless/reg.c b/net/wireless/reg.c
index a2b09c2df1bf..a1f069da79a4 100644
--- a/net/wireless/reg.c
+++ b/net/wireless/reg.c
@@ -101,6 +101,9 @@ struct reg_beacon {
         struct ieee80211_channel chan;
 };
 
+static void wiphy_update_regulatory(struct wiphy *wiphy,
+                                    enum nl80211_reg_initiator initiator);
+
 static void reg_todo(struct work_struct *work);
 static DECLARE_WORK(reg_work, reg_todo);
 
@@ -1118,11 +1121,13 @@ static void reg_process_ht_flags(struct wiphy *wiphy)
 
 }
 
-void wiphy_update_regulatory(struct wiphy *wiphy,
-                             enum nl80211_reg_initiator initiator)
+static void wiphy_update_regulatory(struct wiphy *wiphy,
+                                    enum nl80211_reg_initiator initiator)
 {
         enum ieee80211_band band;
 
+        assert_reg_lock();
+
         if (ignore_reg_update(wiphy, initiator))
                 return;
 
@@ -1137,6 +1142,14 @@ void wiphy_update_regulatory(struct wiphy *wiphy,
                 wiphy->reg_notifier(wiphy, last_request);
 }
 
+void regulatory_update(struct wiphy *wiphy,
+                       enum nl80211_reg_initiator setby)
+{
+        mutex_lock(&reg_mutex);
+        wiphy_update_regulatory(wiphy, setby);
+        mutex_unlock(&reg_mutex);
+}
+
 static void handle_channel_custom(struct wiphy *wiphy,
                                   enum ieee80211_band band,
                                   unsigned int chan_idx,
diff --git a/net/wireless/reg.h b/net/wireless/reg.h
index b67d1c3a2fb9..4a56799d868d 100644
--- a/net/wireless/reg.h
+++ b/net/wireless/reg.h
@@ -16,6 +16,8 @@ void regulatory_exit(void);
 
 int set_regdom(const struct ieee80211_regdomain *rd);
 
+void regulatory_update(struct wiphy *wiphy, enum nl80211_reg_initiator setby);
+
 /**
  * regulatory_hint_found_beacon - hints a beacon was found on a channel
  * @wiphy: the wireless device where the beacon was found on