[ 3.5.y.z extended stable ] Patch "iwlwifi: mvm: refuse connection to APs with BI < 16" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    iwlwifi: mvm: refuse connection to APs with BI < 16

to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.5.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 95964b8c0990269a60d1c8fcc05459fb4cebe544 Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg at intel.com>
Date: Thu, 4 Jul 2013 15:55:29 +0200
Subject: [PATCH] iwlwifi: mvm: refuse connection to APs with BI < 16

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>
---
 drivers/net/wireless/iwlwifi/iwl-mac80211.c | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/iwlwifi/iwl-mac80211.c b/drivers/net/wireless/iwlwifi/iwl-mac80211.c
index a0b0b78..2c86c55 100644
--- a/drivers/net/wireless/iwlwifi/iwl-mac80211.c
+++ b/drivers/net/wireless/iwlwifi/iwl-mac80211.c
@@ -776,9 +776,23 @@ 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 &&
@@ -846,6 +860,7 @@ 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");

--
1.8.3.2