[3.13.y.z extended stable] Patch "mac80211: fix suspend vs. authentication race" has been added to staging queue

[Kamal Mostafa]

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

    mac80211: fix suspend vs. authentication race

to the linux-3.13.y-queue branch of the 3.13.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-3.13.y-queue

This patch is scheduled to be released in version 3.13.11.1.

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

For more information about the 3.13.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From a0cf2abfc72d2c436c4110b37da8900c2342e527 Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg at intel.com>
Date: Wed, 19 Mar 2014 09:55:55 +0100
Subject: mac80211: fix suspend vs. authentication race

commit 1a1cb744de160ee70086a77afff605bbc275d291 upstream.

Since Stanislaw's patch removing the quiescing code, mac80211 had
a race regarding suspend vs. authentication: as cfg80211 doesn't
track authentication attempts, it can't abort them. Therefore the
attempts may be kept running while suspending, which can lead to
all kinds of issues, in at least some cases causing an error in
iwlmvm firmware.

Fix this by aborting the authentication attempt when suspending.

Fixes: 12e7f517029d ("mac80211: cleanup generic suspend/resume procedures")
Signed-off-by: Johannes Berg <johannes.berg at intel.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 net/mac80211/ieee80211_i.h |  1 +
 net/mac80211/mlme.c        | 26 ++++++++++++++++++++++++++
 net/mac80211/pm.c          | 14 +++++++++++---
 3 files changed, 38 insertions(+), 3 deletions(-)

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 4aea4e7..1fc9190 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -1346,6 +1346,7 @@ void ieee80211_sta_reset_conn_monitor(struct ieee80211_sub_if_data *sdata);
 void ieee80211_mgd_stop(struct ieee80211_sub_if_data *sdata);
 void ieee80211_mgd_conn_tx_status(struct ieee80211_sub_if_data *sdata,
 				  __le16 fc, bool acked);
+void ieee80211_mgd_quiesce(struct ieee80211_sub_if_data *sdata);
 void ieee80211_sta_restart(struct ieee80211_sub_if_data *sdata);

 /* IBSS code */
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 90ee798..4eef5fd 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -3487,6 +3487,32 @@ static void ieee80211_restart_sta_timer(struct ieee80211_sub_if_data *sdata)
 }

 #ifdef CONFIG_PM
+void ieee80211_mgd_quiesce(struct ieee80211_sub_if_data *sdata)
+{
+	struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
+	u8 frame_buf[IEEE80211_DEAUTH_FRAME_LEN];
+
+	sdata_lock(sdata);
+
+	if (ifmgd->auth_data) {
+		/*
+		 * If we are trying to authenticate while suspending, cfg80211
+		 * won't know and won't actually abort those attempts, thus we
+		 * need to do that ourselves.
+		 */
+		ieee80211_send_deauth_disassoc(sdata,
+					       ifmgd->auth_data->bss->bssid,
+					       IEEE80211_STYPE_DEAUTH,
+					       WLAN_REASON_DEAUTH_LEAVING,
+					       false, frame_buf);
+		ieee80211_destroy_auth_data(sdata, false);
+		cfg80211_tx_mlme_mgmt(sdata->dev, frame_buf,
+				      IEEE80211_DEAUTH_FRAME_LEN);
+	}
+
+	sdata_unlock(sdata);
+}
+
 void ieee80211_sta_restart(struct ieee80211_sub_if_data *sdata)
 {
 	struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
diff --git a/net/mac80211/pm.c b/net/mac80211/pm.c
index 3401262..efb510e 100644
--- a/net/mac80211/pm.c
+++ b/net/mac80211/pm.c
@@ -101,10 +101,18 @@ int __ieee80211_suspend(struct ieee80211_hw *hw, struct cfg80211_wowlan *wowlan)

 	/* remove all interfaces that were created in the driver */
 	list_for_each_entry(sdata, &local->interfaces, list) {
-		if (!ieee80211_sdata_running(sdata) ||
-		    sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
-		    sdata->vif.type == NL80211_IFTYPE_MONITOR)
+		if (!ieee80211_sdata_running(sdata))
 			continue;
+		switch (sdata->vif.type) {
+		case NL80211_IFTYPE_AP_VLAN:
+		case NL80211_IFTYPE_MONITOR:
+			continue;
+		case NL80211_IFTYPE_STATION:
+			ieee80211_mgd_quiesce(sdata);
+			break;
+		default:
+			break;
+		}

 		drv_remove_interface(local, sdata);
 	}
--
1.9.1