Merge tag 'batadv-net-pullrequest-20250207' of git://git.open-mesh.org/linux-merge

Simon Wunderlich says:

====================
Here are some batman-adv bugfixes:

 - Fix panic during interface removal in BATMAN V, by Andy Strohman

 - Cleanup BATMAN V/ELP metric handling, by Sven Eckelmann (2 patches)

 - Fix incorrect offset in batadv_tt_tvlv_ogm_handler_v1(),
   by Remi Pommarel

* tag 'batadv-net-pullrequest-20250207' of git://git.open-mesh.org/linux-merge:
  batman-adv: Fix incorrect offset in batadv_tt_tvlv_ogm_handler_v1()
  batman-adv: Drop unmanaged ELP metric worker
  batman-adv: Ignore neighbor throughput metrics in error case
  batman-adv: fix panic during interface removal
====================

Link: https://patch.msgid.link/20250207095823.26043-1-sw@simonwunderlich.de
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Author: Paolo Abeni

net/batman-adv/bat_v.c

@@ -113,8 +113,6 @@ static void
 batadv_v_hardif_neigh_init(struct batadv_hardif_neigh_node *hardif_neigh)
 {
 	ewma_throughput_init(&hardif_neigh->bat_v.throughput);
-	INIT_WORK(&hardif_neigh->bat_v.metric_work,
-		  batadv_v_elp_throughput_metric_update);
 }
 
 /**

net/batman-adv/bat_v_elp.c

@@ -18,6 +18,7 @@
 #include <linux/if_ether.h>
 #include <linux/jiffies.h>
 #include <linux/kref.h>
+#include <linux/list.h>
 #include <linux/minmax.h>
 #include <linux/netdevice.h>
 #include <linux/nl80211.h>
@@ -26,6 +27,7 @@
 #include <linux/rcupdate.h>
 #include <linux/rtnetlink.h>
 #include <linux/skbuff.h>
+#include <linux/slab.h>
 #include <linux/stddef.h>
 #include <linux/string.h>
 #include <linux/types.h>
@@ -41,6 +43,18 @@
 #include "routing.h"
 #include "send.h"
 
+/**
+ * struct batadv_v_metric_queue_entry - list of hardif neighbors which require
+ *  and metric update
+ */
+struct batadv_v_metric_queue_entry {
+	/** @hardif_neigh: hardif neighbor scheduled for metric update */
+	struct batadv_hardif_neigh_node *hardif_neigh;
+
+	/** @list: list node for metric_queue */
+	struct list_head list;
+};
+
 /**
  * batadv_v_elp_start_timer() - restart timer for ELP periodic work
  * @hard_iface: the interface for which the timer has to be reset
@@ -59,25 +73,36 @@ static void batadv_v_elp_start_timer(struct batadv_hard_iface *hard_iface)
 /**
  * batadv_v_elp_get_throughput() - get the throughput towards a neighbour
  * @neigh: the neighbour for which the throughput has to be obtained
+ * @pthroughput: calculated throughput towards the given neighbour in multiples
+ *  of 100kpbs (a value of '1' equals 0.1Mbps, '10' equals 1Mbps, etc).
  *
- * Return: The throughput towards the given neighbour in multiples of 100kpbs
- *         (a value of '1' equals 0.1Mbps, '10' equals 1Mbps, etc).
+ * Return: true when value behind @pthroughput was set
  */
-static u32 batadv_v_elp_get_throughput(struct batadv_hardif_neigh_node *neigh)
+static bool batadv_v_elp_get_throughput(struct batadv_hardif_neigh_node *neigh,
+					u32 *pthroughput)
 {
 	struct batadv_hard_iface *hard_iface = neigh->if_incoming;
+	struct net_device *soft_iface = hard_iface->soft_iface;
 	struct ethtool_link_ksettings link_settings;
 	struct net_device *real_netdev;
 	struct station_info sinfo;
 	u32 throughput;
 	int ret;
 
+	/* don't query throughput when no longer associated with any
+	 * batman-adv interface
+	 */
+	if (!soft_iface)
+		return false;
+
 	/* if the user specified a customised value for this interface, then
 	 * return it directly
 	 */
 	throughput =  atomic_read(&hard_iface->bat_v.throughput_override);
-	if (throughput != 0)
-		return throughput;
+	if (throughput != 0) {
+		*pthroughput = throughput;
+		return true;
+	}
 
 	/* if this is a wireless device, then ask its throughput through
 	 * cfg80211 API
@@ -104,27 +129,39 @@ static u32 batadv_v_elp_get_throughput(struct batadv_hardif_neigh_node *neigh)
 			 * possible to delete this neighbor. For now set
 			 * the throughput metric to 0.
 			 */
-			return 0;
+			*pthroughput = 0;
+			return true;
 		}
 		if (ret)
 			goto default_throughput;
 
-		if (sinfo.filled & BIT(NL80211_STA_INFO_EXPECTED_THROUGHPUT))
-			return sinfo.expected_throughput / 100;
+		if (sinfo.filled & BIT(NL80211_STA_INFO_EXPECTED_THROUGHPUT)) {
+			*pthroughput = sinfo.expected_throughput / 100;
+			return true;
+		}
 
 		/* try to estimate the expected throughput based on reported tx
 		 * rates
 		 */
-		if (sinfo.filled & BIT(NL80211_STA_INFO_TX_BITRATE))
-			return cfg80211_calculate_bitrate(&sinfo.txrate) / 3;
+		if (sinfo.filled & BIT(NL80211_STA_INFO_TX_BITRATE)) {
+			*pthroughput = cfg80211_calculate_bitrate(&sinfo.txrate) / 3;
+			return true;
+		}
 
 		goto default_throughput;
 	}
 
+	/* only use rtnl_trylock because the elp worker will be cancelled while
+	 * the rntl_lock is held. the cancel_delayed_work_sync() would otherwise
+	 * wait forever when the elp work_item was started and it is then also
+	 * trying to rtnl_lock
+	 */
+	if (!rtnl_trylock())
+		return false;
+
 	/* if not a wifi interface, check if this device provides data via
 	 * ethtool (e.g. an Ethernet adapter)
 	 */
-	rtnl_lock();
 	ret = __ethtool_get_link_ksettings(hard_iface->net_dev, &link_settings);
 	rtnl_unlock();
 	if (ret == 0) {
@@ -135,13 +172,15 @@ static u32 batadv_v_elp_get_throughput(struct batadv_hardif_neigh_node *neigh)
 			hard_iface->bat_v.flags &= ~BATADV_FULL_DUPLEX;
 
 		throughput = link_settings.base.speed;
-		if (throughput && throughput != SPEED_UNKNOWN)
-			return throughput * 10;
+		if (throughput && throughput != SPEED_UNKNOWN) {
+			*pthroughput = throughput * 10;
+			return true;
+		}
 	}
 
 default_throughput:
 	if (!(hard_iface->bat_v.flags & BATADV_WARNING_DEFAULT)) {
-		batadv_info(hard_iface->soft_iface,
+		batadv_info(soft_iface,
 			    "WiFi driver or ethtool info does not provide information about link speeds on interface %s, therefore defaulting to hardcoded throughput values of %u.%1u Mbps. Consider overriding the throughput manually or checking your driver.\n",
 			    hard_iface->net_dev->name,
 			    BATADV_THROUGHPUT_DEFAULT_VALUE / 10,
@@ -150,31 +189,26 @@ static u32 batadv_v_elp_get_throughput(struct batadv_hardif_neigh_node *neigh)
 	}
 
 	/* if none of the above cases apply, return the base_throughput */
-	return BATADV_THROUGHPUT_DEFAULT_VALUE;
+	*pthroughput = BATADV_THROUGHPUT_DEFAULT_VALUE;
+	return true;
 }
 
 /**
  * batadv_v_elp_throughput_metric_update() - worker updating the throughput
  *  metric of a single hop neighbour
- * @work: the work queue item
+ * @neigh: the neighbour to probe
  */
-void batadv_v_elp_throughput_metric_update(struct work_struct *work)
+static void
+batadv_v_elp_throughput_metric_update(struct batadv_hardif_neigh_node *neigh)
 {
-	struct batadv_hardif_neigh_node_bat_v *neigh_bat_v;
-	struct batadv_hardif_neigh_node *neigh;
-
-	neigh_bat_v = container_of(work, struct batadv_hardif_neigh_node_bat_v,
-				   metric_work);
-	neigh = container_of(neigh_bat_v, struct batadv_hardif_neigh_node,
-			     bat_v);
+	u32 throughput;
+	bool valid;
 
-	ewma_throughput_add(&neigh->bat_v.throughput,
-			    batadv_v_elp_get_throughput(neigh));
+	valid = batadv_v_elp_get_throughput(neigh, &throughput);
+	if (!valid)
+		return;
 
-	/* decrement refcounter to balance increment performed before scheduling
-	 * this task
-	 */
-	batadv_hardif_neigh_put(neigh);
+	ewma_throughput_add(&neigh->bat_v.throughput, throughput);
 }
 
 /**
@@ -248,14 +282,16 @@ batadv_v_elp_wifi_neigh_probe(struct batadv_hardif_neigh_node *neigh)
  */
 static void batadv_v_elp_periodic_work(struct work_struct *work)
 {
+	struct batadv_v_metric_queue_entry *metric_entry;
+	struct batadv_v_metric_queue_entry *metric_safe;
 	struct batadv_hardif_neigh_node *hardif_neigh;
 	struct batadv_hard_iface *hard_iface;
 	struct batadv_hard_iface_bat_v *bat_v;
 	struct batadv_elp_packet *elp_packet;
+	struct list_head metric_queue;
 	struct batadv_priv *bat_priv;
 	struct sk_buff *skb;
 	u32 elp_interval;
-	bool ret;
 
 	bat_v = container_of(work, struct batadv_hard_iface_bat_v, elp_wq.work);
 	hard_iface = container_of(bat_v, struct batadv_hard_iface, bat_v);
@@ -291,6 +327,8 @@ static void batadv_v_elp_periodic_work(struct work_struct *work)
 
 	atomic_inc(&hard_iface->bat_v.elp_seqno);
 
+	INIT_LIST_HEAD(&metric_queue);
+
 	/* The throughput metric is updated on each sent packet. This way, if a
 	 * node is dead and no longer sends packets, batman-adv is still able to
 	 * react timely to its death.
@@ -315,16 +353,28 @@ static void batadv_v_elp_periodic_work(struct work_struct *work)
 
 		/* Reading the estimated throughput from cfg80211 is a task that
 		 * may sleep and that is not allowed in an rcu protected
-		 * context. Therefore schedule a task for that.
+		 * context. Therefore add it to metric_queue and process it
+		 * outside rcu protected context.
 		 */
-		ret = queue_work(batadv_event_workqueue,
-				 &hardif_neigh->bat_v.metric_work);
-
-		if (!ret)
+		metric_entry = kzalloc(sizeof(*metric_entry), GFP_ATOMIC);
+		if (!metric_entry) {
 			batadv_hardif_neigh_put(hardif_neigh);
+			continue;
+		}
+
+		metric_entry->hardif_neigh = hardif_neigh;
+		list_add(&metric_entry->list, &metric_queue);
 	}
 	rcu_read_unlock();
 
+	list_for_each_entry_safe(metric_entry, metric_safe, &metric_queue, list) {
+		batadv_v_elp_throughput_metric_update(metric_entry->hardif_neigh);
+
+		batadv_hardif_neigh_put(metric_entry->hardif_neigh);
+		list_del(&metric_entry->list);
+		kfree(metric_entry);
+	}
+
 restart_timer:
 	batadv_v_elp_start_timer(hard_iface);
 out:

net/batman-adv/bat_v_elp.h

@@ -10,7 +10,6 @@
 #include "main.h"
 
 #include <linux/skbuff.h>
-#include <linux/workqueue.h>
 
 int batadv_v_elp_iface_enable(struct batadv_hard_iface *hard_iface);
 void batadv_v_elp_iface_disable(struct batadv_hard_iface *hard_iface);
@@ -19,6 +18,5 @@ void batadv_v_elp_iface_activate(struct batadv_hard_iface *primary_iface,
 void batadv_v_elp_primary_iface_set(struct batadv_hard_iface *primary_iface);
 int batadv_v_elp_packet_recv(struct sk_buff *skb,
 			     struct batadv_hard_iface *if_incoming);
-void batadv_v_elp_throughput_metric_update(struct work_struct *work);
 
 #endif /* _NET_BATMAN_ADV_BAT_V_ELP_H_ */

net/batman-adv/translation-table.c

@@ -3937,23 +3937,21 @@ static void batadv_tt_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv,
 	struct batadv_tvlv_tt_change *tt_change;
 	struct batadv_tvlv_tt_data *tt_data;
 	u16 num_entries, num_vlan;
-	size_t flex_size;
+	size_t tt_data_sz;
 
 	if (tvlv_value_len < sizeof(*tt_data))
 		return;
 
 	tt_data = tvlv_value;
-	tvlv_value_len -= sizeof(*tt_data);
-
 	num_vlan = ntohs(tt_data->num_vlan);
 
-	flex_size = flex_array_size(tt_data, vlan_data, num_vlan);
-	if (tvlv_value_len < flex_size)
+	tt_data_sz = struct_size(tt_data, vlan_data, num_vlan);
+	if (tvlv_value_len < tt_data_sz)
 		return;
 
 	tt_change = (struct batadv_tvlv_tt_change *)((void *)tt_data
-						     + flex_size);
-	tvlv_value_len -= flex_size;
+						     + tt_data_sz);
+	tvlv_value_len -= tt_data_sz;
 
 	num_entries = batadv_tt_entries(tvlv_value_len);
 

net/batman-adv/types.h

@@ -596,9 +596,6 @@ struct batadv_hardif_neigh_node_bat_v {
 	 *  neighbor
 	 */
 	unsigned long last_unicast_tx;
-
-	/** @metric_work: work queue callback item for metric update */
-	struct work_struct metric_work;
 };
 
 /**