wifi: mac80211: fix a queue stall in certain cases of CSA

If we got an unprotected action frame with CSA and then we heard the
beacon with the CSA IE, we'll block the queues with the CSA reason
twice. Since this reason is refcounted, we won't wake up the queues
since we wake them up only once and the ref count will never reach 0.
This led to blocked queues that prevented any activity (even
disconnection wouldn't reset the queue state and the only way to recover
would be to reload the kernel module.

Fix this by not refcounting the CSA reason.
It becomes now pointless to maintain the csa_blocked_queues state.
Remove it.

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Fixes: 414e090bc41d ("wifi: mac80211: restrict public action ECSA frame handling")
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=219447
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://patch.msgid.link/20241119173108.5ea90828c2cc.I4f89e58572fb71ae48e47a81e74595cac410fbac@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

5 files changed, 48 insertions, 41 deletions

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 506b7c469711..b853afe2d2a6 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -3726,13 +3726,12 @@ void ieee80211_csa_finish(struct ieee80211_vif *vif, unsigned int link_id)
 }
 EXPORT_SYMBOL(ieee80211_csa_finish);
 
-void ieee80211_channel_switch_disconnect(struct ieee80211_vif *vif, bool block_tx)
+void ieee80211_channel_switch_disconnect(struct ieee80211_vif *vif)
 {
 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 	struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
 	struct ieee80211_local *local = sdata->local;
 
-	sdata->csa_blocked_queues = block_tx;
 	sdata_info(sdata, "channel switch failed, disconnecting\n");
 	wiphy_work_queue(local->hw.wiphy, &ifmgd->csa_connection_drop_work);
 }
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index a00096dd787b..9f0db39b28ff 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -1104,8 +1104,6 @@ struct ieee80211_sub_if_data {
 
 	unsigned long state;
 
-	bool csa_blocked_queues;
-
 	char name[IFNAMSIZ];
 
 	struct ieee80211_fragment_cache frags;
@@ -2412,17 +2410,13 @@ void ieee80211_send_4addr_nullfunc(struct ieee80211_local *local,
 				   struct ieee80211_sub_if_data *sdata);
 void ieee80211_sta_tx_notify(struct ieee80211_sub_if_data *sdata,
 			     struct ieee80211_hdr *hdr, bool ack, u16 tx_time);
-
+unsigned int
+ieee80211_get_vif_queues(struct ieee80211_local *local,
+			 struct ieee80211_sub_if_data *sdata);
 void ieee80211_wake_queues_by_reason(struct ieee80211_hw *hw,
 				     unsigned long queues,
 				     enum queue_stop_reason reason,
 				     bool refcounted);
-void ieee80211_stop_vif_queues(struct ieee80211_local *local,
-			       struct ieee80211_sub_if_data *sdata,
-			       enum queue_stop_reason reason);
-void ieee80211_wake_vif_queues(struct ieee80211_local *local,
-			       struct ieee80211_sub_if_data *sdata,
-			       enum queue_stop_reason reason);
 void ieee80211_stop_queues_by_reason(struct ieee80211_hw *hw,
 				     unsigned long queues,
 				     enum queue_stop_reason reason,
@@ -2433,6 +2427,43 @@ void ieee80211_wake_queue_by_reason(struct ieee80211_hw *hw, int queue,
 void ieee80211_stop_queue_by_reason(struct ieee80211_hw *hw, int queue,
 				    enum queue_stop_reason reason,
 				    bool refcounted);
+static inline void
+ieee80211_stop_vif_queues(struct ieee80211_local *local,
+			  struct ieee80211_sub_if_data *sdata,
+			  enum queue_stop_reason reason)
+{
+	ieee80211_stop_queues_by_reason(&local->hw,
+					ieee80211_get_vif_queues(local, sdata),
+					reason, true);
+}
+
+static inline void
+ieee80211_wake_vif_queues(struct ieee80211_local *local,
+			  struct ieee80211_sub_if_data *sdata,
+			  enum queue_stop_reason reason)
+{
+	ieee80211_wake_queues_by_reason(&local->hw,
+					ieee80211_get_vif_queues(local, sdata),
+					reason, true);
+}
+static inline void
+ieee80211_stop_vif_queues_norefcount(struct ieee80211_local *local,
+				     struct ieee80211_sub_if_data *sdata,
+				     enum queue_stop_reason reason)
+{
+	ieee80211_stop_queues_by_reason(&local->hw,
+					ieee80211_get_vif_queues(local, sdata),
+					reason, false);
+}
+static inline void
+ieee80211_wake_vif_queues_norefcount(struct ieee80211_local *local,
+				     struct ieee80211_sub_if_data *sdata,
+				     enum queue_stop_reason reason)
+{
+	ieee80211_wake_queues_by_reason(&local->hw,
+					ieee80211_get_vif_queues(local, sdata),
+					reason, false);
+}
 void ieee80211_add_pending_skb(struct ieee80211_local *local,
 			       struct sk_buff *skb);
 void ieee80211_add_pending_skbs(struct ieee80211_local *local,
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index a8fbedd530f4..a36d295f127c 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -2374,18 +2374,14 @@ void ieee80211_vif_block_queues_csa(struct ieee80211_sub_if_data *sdata)
 	if (ieee80211_hw_check(&local->hw, HANDLES_QUIET_CSA))
 		return;
 
-	ieee80211_stop_vif_queues(local, sdata,
-				  IEEE80211_QUEUE_STOP_REASON_CSA);
-	sdata->csa_blocked_queues = true;
+	ieee80211_stop_vif_queues_norefcount(local, sdata,
+					     IEEE80211_QUEUE_STOP_REASON_CSA);
 }
 
 void ieee80211_vif_unblock_queues_csa(struct ieee80211_sub_if_data *sdata)
 {
 	struct ieee80211_local *local = sdata->local;
 
-	if (sdata->csa_blocked_queues) {
-		ieee80211_wake_vif_queues(local, sdata,
-					  IEEE80211_QUEUE_STOP_REASON_CSA);
-		sdata->csa_blocked_queues = false;
-	}
+	ieee80211_wake_vif_queues_norefcount(local, sdata,
+					     IEEE80211_QUEUE_STOP_REASON_CSA);
 }
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 480b664151c9..61c318f5239f 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -2638,8 +2638,6 @@ ieee80211_sta_process_chanswitch(struct ieee80211_link_data *link,
 	 */
 	link->conf->csa_active = true;
 	link->u.mgd.csa.blocked_tx = csa_ie.mode;
-	sdata->csa_blocked_queues =
-		csa_ie.mode && !ieee80211_hw_check(&local->hw, HANDLES_QUIET_CSA);
 
 	wiphy_work_queue(sdata->local->hw.wiphy,
 			 &ifmgd->csa_connection_drop_work);
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index c13b4e718e77..dc0b74443c8d 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -657,7 +657,7 @@ void ieee80211_wake_queues(struct ieee80211_hw *hw)
 }
 EXPORT_SYMBOL(ieee80211_wake_queues);
 
-static unsigned int
+unsigned int
 ieee80211_get_vif_queues(struct ieee80211_local *local,
 			 struct ieee80211_sub_if_data *sdata)
 {
@@ -669,7 +669,8 @@ ieee80211_get_vif_queues(struct ieee80211_local *local,
 		queues = 0;
 
 		for (ac = 0; ac < IEEE80211_NUM_ACS; ac++)
-			queues |= BIT(sdata->vif.hw_queue[ac]);
+			if (sdata->vif.hw_queue[ac] != IEEE80211_INVAL_HW_QUEUE)
+				queues |= BIT(sdata->vif.hw_queue[ac]);
 		if (sdata->vif.cab_queue != IEEE80211_INVAL_HW_QUEUE)
 			queues |= BIT(sdata->vif.cab_queue);
 	} else {
@@ -724,24 +725,6 @@ void ieee80211_flush_queues(struct ieee80211_local *local,
 	__ieee80211_flush_queues(local, sdata, 0, drop);
 }
 
-void ieee80211_stop_vif_queues(struct ieee80211_local *local,
-			       struct ieee80211_sub_if_data *sdata,
-			       enum queue_stop_reason reason)
-{
-	ieee80211_stop_queues_by_reason(&local->hw,
-					ieee80211_get_vif_queues(local, sdata),
-					reason, true);
-}
-
-void ieee80211_wake_vif_queues(struct ieee80211_local *local,
-			       struct ieee80211_sub_if_data *sdata,
-			       enum queue_stop_reason reason)
-{
-	ieee80211_wake_queues_by_reason(&local->hw,
-					ieee80211_get_vif_queues(local, sdata),
-					reason, true);
-}
-
 static void __iterate_interfaces(struct ieee80211_local *local,
 				 u32 iter_flags,
 				 void (*iterator)(void *data, u8 *mac,