batman-adv: Add missing hardif_free_ref in forw_packet_free

add_bcast_packet_to_list increases the refcount for if_incoming but the
reference count is never decreased. The reference count must be
increased for all kinds of forwarded packets which have the primary
interface stored and forw_packet_free must decrease them. Also
purge_outstanding_packets has to invoke forw_packet_free when a work
item was really cancelled.

This regression was introduced in
32ae9b221e788413ce68feaae2ca39e406211a0a.

Reported-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Sven Eckelmann <sven@narfation.org>

2 files changed, 26 insertions, 5 deletions

diff --git a/net/batman-adv/aggregation.c b/net/batman-adv/aggregation.c
index 9b9459024479..a8c32030527c 100644
--- a/net/batman-adv/aggregation.c
+++ b/net/batman-adv/aggregation.c
@@ -23,6 +23,7 @@
 #include "aggregation.h"
 #include "send.h"
 #include "routing.h"
+#include "hard-interface.h"
 
 /* calculate the size of the tt information for a given packet */
 static int tt_len(struct batman_packet *batman_packet)
@@ -105,12 +106,15 @@ static void new_aggregated_packet(unsigned char *packet_buff, int packet_len,
         struct forw_packet *forw_packet_aggr;
         unsigned char *skb_buff;
 
+        if (!atomic_inc_not_zero(&if_incoming->refcount))
+                return;
+
         /* own packet should always be scheduled */
         if (!own_packet) {
                 if (!atomic_dec_not_zero(&bat_priv->batman_queue_left)) {
                         bat_dbg(DBG_BATMAN, bat_priv,
                                 "batman packet queue full\n");
-                        return;
+                        goto out;
                 }
         }
 
@@ -118,7 +122,7 @@ static void new_aggregated_packet(unsigned char *packet_buff, int packet_len,
         if (!forw_packet_aggr) {
                 if (!own_packet)
                         atomic_inc(&bat_priv->batman_queue_left);
-                return;
+                goto out;
         }
 
         if ((atomic_read(&bat_priv->aggregated_ogms)) &&
@@ -133,7 +137,7 @@ static void new_aggregated_packet(unsigned char *packet_buff, int packet_len,
                 if (!own_packet)
                         atomic_inc(&bat_priv->batman_queue_left);
                 kfree(forw_packet_aggr);
-                return;
+                goto out;
         }
         skb_reserve(forw_packet_aggr->skb, sizeof(struct ethhdr));
 
@@ -164,6 +168,10 @@ static void new_aggregated_packet(unsigned char *packet_buff, int packet_len,
         queue_delayed_work(bat_event_workqueue,
                            &forw_packet_aggr->delayed_work,
                            send_time - jiffies);
+
+        return;
+out:
+        hardif_free_ref(if_incoming);
 }
 
 /* aggregate a new packet into the existing aggregation */
diff --git a/net/batman-adv/send.c b/net/batman-adv/send.c
index f30d0c69ccbb..76daa46efe19 100644
--- a/net/batman-adv/send.c
+++ b/net/batman-adv/send.c
@@ -377,6 +377,8 @@ static void forw_packet_free(struct forw_packet *forw_packet)
 {
         if (forw_packet->skb)
                 kfree_skb(forw_packet->skb);
+        if (forw_packet->if_incoming)
+                hardif_free_ref(forw_packet->if_incoming);
         kfree(forw_packet);
 }
 
@@ -539,6 +541,7 @@ void purge_outstanding_packets(struct bat_priv *bat_priv,
 {
         struct forw_packet *forw_packet;
         struct hlist_node *tmp_node, *safe_tmp_node;
+        bool pending;
 
         if (hard_iface)
                 bat_dbg(DBG_BATMAN, bat_priv,
@@ -567,8 +570,13 @@ void purge_outstanding_packets(struct bat_priv *bat_priv,
                  * send_outstanding_bcast_packet() will lock the list to
                  * delete the item from the list
                  */
-                cancel_delayed_work_sync(&forw_packet->delayed_work);
+                pending = cancel_delayed_work_sync(&forw_packet->delayed_work);
                 spin_lock_bh(&bat_priv->forw_bcast_list_lock);
+
+                if (pending) {
+                        hlist_del(&forw_packet->list);
+                        forw_packet_free(forw_packet);
+                }
         }
         spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 
@@ -591,8 +599,13 @@ void purge_outstanding_packets(struct bat_priv *bat_priv,
                  * send_outstanding_bat_packet() will lock the list to
                  * delete the item from the list
                  */
-                cancel_delayed_work_sync(&forw_packet->delayed_work);
+                pending = cancel_delayed_work_sync(&forw_packet->delayed_work);
                 spin_lock_bh(&bat_priv->forw_bat_list_lock);
+
+                if (pending) {
+                        hlist_del(&forw_packet->list);
+                        forw_packet_free(forw_packet);
+                }
         }
         spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 }