[PATCH 045/133] iwlwifi: mvm: refuse connection to APs with BI < 16

[Kamal Mostafa]

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

------------------

From: Johannes Berg <johannes.berg at intel.com>

commit 48bc13072109ea58465542aa1ee31b4e1065468a upstream.

Due to a firmware bug, it crashes when the beacon interval
is smaller than 16. Avoid this by refusing the station state
change creating the AP station, causing mac80211 to abandon
the attempt to connect to the AP, and eventually wpa_s to
blacklist it.

Reviewed-by: Emmanuel Grumbach <emmanuel.grumbach at intel.com>
Signed-off-by: Johannes Berg <johannes.berg at intel.com>
[ luis: backported to 3.5:
  - file renamed: drivers/net/wireless/iwlwifi/mvm/mac80211.c ->
    drivers/net/wireless/iwlwifi/iwl-mac80211.c
  - adjusted context
  - changed IWL_ERR 1st argument to 'priv'
  - removed redundant condition in 'if' statement ]
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/net/wireless/iwlwifi/dvm/mac80211.c | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/iwlwifi/dvm/mac80211.c b/drivers/net/wireless/iwlwifi/dvm/mac80211.c
index 3163e0f..c784f69 100644
--- a/drivers/net/wireless/iwlwifi/dvm/mac80211.c
+++ b/drivers/net/wireless/iwlwifi/dvm/mac80211.c
@@ -786,9 +786,23 @@ static int iwlagn_mac_sta_state(struct ieee80211_hw *hw,
 	mutex_lock(&priv->mutex);
 	if (vif->type == NL80211_IFTYPE_STATION) {
 		if (old_state == IEEE80211_STA_NOTEXIST &&
-		    new_state == IEEE80211_STA_NONE)
+		    new_state == IEEE80211_STA_NONE) {
+			/*
+			 * Firmware bug - it'll crash if the beacon interval is less
+			 * than 16. We can't avoid connecting at all, so refuse the
+			 * station state change, this will cause mac80211 to abandon
+			 * attempts to connect to this AP, and eventually wpa_s will
+			 * blacklist the AP...
+			 */
+			if (vif->bss_conf.beacon_int < 16) {
+				IWL_ERR(priv,
+					"AP %pM beacon interval is %d, refusing due to firmware bug!\n",
+					sta->addr, vif->bss_conf.beacon_int);
+				ret = -EINVAL;
+				goto out_unlock;
+			}
 			op = ADD;
-		else if (old_state == IEEE80211_STA_NONE &&
+		} else if (old_state == IEEE80211_STA_NONE &&
 			 new_state == IEEE80211_STA_NOTEXIST)
 			op = REMOVE;
 		else if (old_state == IEEE80211_STA_AUTH &&
@@ -856,6 +870,7 @@ static int iwlagn_mac_sta_state(struct ieee80211_hw *hw,
 	if (iwl_is_rfkill(priv))
 		ret = 0;
 
+out_unlock:
 	mutex_unlock(&priv->mutex);
 	IWL_DEBUG_MAC80211(priv, "leave\n");
 
-- 
1.8.1.2