2 files changed, 24 insertions, 2 deletions

diff --git a/include/linux/nl80211.h b/include/linux/nl80211.h
index 0edb2566c14c..fb877b5621b7 100644
--- a/include/linux/nl80211.h
+++ b/include/linux/nl80211.h
@@ -1307,7 +1307,11 @@ enum nl80211_bitrate_attr {
  *      wireless core it thinks its knows the regulatory domain we should be in.
  * @NL80211_REGDOM_SET_BY_COUNTRY_IE: the wireless core has received an
  *      802.11 country information element with regulatory information it
- *      thinks we should consider.
+ *      thinks we should consider. cfg80211 only processes the country
+ *      code from the IE, and relies on the regulatory domain information
+ *      structure pased by userspace (CRDA) from our wireless-regdb.
+ *      If a channel is enabled but the country code indicates it should
+ *      be disabled we disable the channel and re-enable it upon disassociation.
  */
 enum nl80211_reg_initiator {
         NL80211_REGDOM_SET_BY_CORE,
diff --git a/net/wireless/reg.c b/net/wireless/reg.c
index 1bc8131a5185..8ab65f2afe70 100644
--- a/net/wireless/reg.c
+++ b/net/wireless/reg.c
@@ -750,8 +750,26 @@ static void handle_channel(struct wiphy *wiphy,
                           desired_bw_khz,
                           &reg_rule);
 
-        if (r)
+        if (r) {
+                /*
+                 * We will disable all channels that do not match our
+                 * recieved regulatory rule unless the hint is coming
+                 * from a Country IE and the Country IE had no information
+                 * about a band. The IEEE 802.11 spec allows for an AP
+                 * to send only a subset of the regulatory rules allowed,
+                 * so an AP in the US that only supports 2.4 GHz may only send
+                 * a country IE with information for the 2.4 GHz band
+                 * while 5 GHz is still supported.
+                 */
+                if (initiator == NL80211_REGDOM_SET_BY_COUNTRY_IE &&
+                    r == -ERANGE)
+                        return;
+
+                REG_DBG_PRINT("cfg80211: Disabling freq %d MHz\n",
+                              chan->center_freq);
+                chan->flags = IEEE80211_CHAN_DISABLED;
                 return;
+        }
 
         power_rule = &reg_rule->power_rule;
         freq_range = &reg_rule->freq_range;