Merge tag 'batman-adv-fix-for-davem' of git://git.open-mesh.org/linux-merge

Antonio Quartulli says:

====================
During the Wireless Battle Mesh v9 in Porto (PT) at the beginning of
May, we managed to uncover and fix some important bugs in our
new B.A.T.M.A.N. V algorithm. These are the fixes we came up with
together with others that I collected in the past weeks:
- avoid potential crash due to NULL pointer dereference in
  B.A.T.M.A.N. V routine when a neigh_ifinfo object is not found, by
  Sven Eckelmann
- avoid use-after-free of skb when counting outgoing bytes, by Florian
  Westphal
- fix neigh_ifinfo object reference counting imbalance when using
  B.A.T.M.A.N. V, by Sven Eckelmann. Such imbalance may lead to the
  impossibility of releasing the related netdev object on shutdown
- avoid invalid memory access in case of error while allocating
  bcast_own_sum when a new hard-interface is added, by Sven Eckelmann
- ensure originator address is updated in OMG/ELP packet content upon
  primary interface address change, by Antonio Quartulli
- fix integer overflow when computing TQ metric (B.A.T.M.A.N. IV), by
  Sven Eckelmann
- avoid race condition while adding new neigh_node which would result
  in having two objects mapping to the same physical neighbour, by
  Linus Lüssing
- ensure originator address is initialized in ELP packet content on
  secondary interfaces, by Marek Lindner
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 58 insertions, 8 deletions

diff --git a/net/batman-adv/bat_v.c b/net/batman-adv/bat_v.c
index 3ff8bd1b7bdc..0a12e5cdd65d 100644
--- a/net/batman-adv/bat_v.c
+++ b/net/batman-adv/bat_v.c
@@ -27,6 +27,7 @@
 #include <linux/rculist.h>
 #include <linux/rcupdate.h>
 #include <linux/seq_file.h>
+#include <linux/stddef.h>
 #include <linux/types.h>
 #include <linux/workqueue.h>
 
@@ -39,6 +40,16 @@
 
 static void batadv_v_iface_activate(struct batadv_hard_iface *hard_iface)
 {
+	struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
+	struct batadv_hard_iface *primary_if;
+
+	primary_if = batadv_primary_if_get_selected(bat_priv);
+
+	if (primary_if) {
+		batadv_v_elp_iface_activate(primary_if, hard_iface);
+		batadv_hardif_put(primary_if);
+	}
+
 	/* B.A.T.M.A.N. V does not use any queuing mechanism, therefore it can
 	 * set the interface as ACTIVE right away, without any risk of race
 	 * condition
@@ -72,16 +83,34 @@ static void batadv_v_iface_disable(struct batadv_hard_iface *hard_iface)
 	batadv_v_elp_iface_disable(hard_iface);
 }
 
-static void batadv_v_iface_update_mac(struct batadv_hard_iface *hard_iface)
-{
-}
-
 static void batadv_v_primary_iface_set(struct batadv_hard_iface *hard_iface)
 {
 	batadv_v_elp_primary_iface_set(hard_iface);
 	batadv_v_ogm_primary_iface_set(hard_iface);
 }
 
+/**
+ * batadv_v_iface_update_mac - react to hard-interface MAC address change
+ * @hard_iface: the modified interface
+ *
+ * If the modified interface is the primary one, update the originator
+ * address in the ELP and OGM messages to reflect the new MAC address.
+ */
+static void batadv_v_iface_update_mac(struct batadv_hard_iface *hard_iface)
+{
+	struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
+	struct batadv_hard_iface *primary_if;
+
+	primary_if = batadv_primary_if_get_selected(bat_priv);
+	if (primary_if != hard_iface)
+		goto out;
+
+	batadv_v_primary_iface_set(hard_iface);
+out:
+	if (primary_if)
+		batadv_hardif_put(primary_if);
+}
+
 static void
 batadv_v_hardif_neigh_init(struct batadv_hardif_neigh_node *hardif_neigh)
 {
@@ -255,14 +284,23 @@ static int batadv_v_neigh_cmp(struct batadv_neigh_node *neigh1,
 			      struct batadv_hard_iface *if_outgoing2)
 {
 	struct batadv_neigh_ifinfo *ifinfo1, *ifinfo2;
+	int ret = 0;
 
 	ifinfo1 = batadv_neigh_ifinfo_get(neigh1, if_outgoing1);
+	if (WARN_ON(!ifinfo1))
+		goto err_ifinfo1;
+
 	ifinfo2 = batadv_neigh_ifinfo_get(neigh2, if_outgoing2);
+	if (WARN_ON(!ifinfo2))
+		goto err_ifinfo2;
 
-	if (WARN_ON(!ifinfo1 || !ifinfo2))
-		return 0;
+	ret = ifinfo1->bat_v.throughput - ifinfo2->bat_v.throughput;
 
-	return ifinfo1->bat_v.throughput - ifinfo2->bat_v.throughput;
+	batadv_neigh_ifinfo_put(ifinfo2);
+err_ifinfo2:
+	batadv_neigh_ifinfo_put(ifinfo1);
+err_ifinfo1:
+	return ret;
 }
 
 static bool batadv_v_neigh_is_sob(struct batadv_neigh_node *neigh1,
@@ -272,14 +310,26 @@ static bool batadv_v_neigh_is_sob(struct batadv_neigh_node *neigh1,
 {
 	struct batadv_neigh_ifinfo *ifinfo1, *ifinfo2;
 	u32 threshold;
+	bool ret = false;
 
 	ifinfo1 = batadv_neigh_ifinfo_get(neigh1, if_outgoing1);
+	if (WARN_ON(!ifinfo1))
+		goto err_ifinfo1;
+
 	ifinfo2 = batadv_neigh_ifinfo_get(neigh2, if_outgoing2);
+	if (WARN_ON(!ifinfo2))
+		goto err_ifinfo2;
 
 	threshold = ifinfo1->bat_v.throughput / 4;
 	threshold = ifinfo1->bat_v.throughput - threshold;
 
-	return ifinfo2->bat_v.throughput > threshold;
+	ret = ifinfo2->bat_v.throughput > threshold;
+
+	batadv_neigh_ifinfo_put(ifinfo2);
+err_ifinfo2:
+	batadv_neigh_ifinfo_put(ifinfo1);
+err_ifinfo1:
+	return ret;
 }
 
 static struct batadv_algo_ops batadv_batman_v __read_mostly = {