[B.A.T.M.A.N.] [PATCH v2 2/2] batman-adv: Fix refcnt leak in batadv_v_*

[Sven Eckelmann]

The functions batadv_neigh_ifinfo_get increase the reference counter of the
batadv_neigh_ifinfo. These have to be reduced again when the reference is
not used anymore to correctly free the objects.

Fixes: b05bbab5e1fc ("batman-adv: B.A.T.M.A.N. V - implement neighbor 
comparison API calls")
Signed-off-by: Sven Eckelmann <s...@narfation.org>
---
v2: Add patch to reduce the reference counter of these functions

 net/batman-adv/bat_v.c | 32 +++++++++++++++++++++++++-------
 1 file changed, 25 insertions(+), 7 deletions(-)

diff --git a/net/batman-adv/bat_v.c b/net/batman-adv/bat_v.c
index f271ae8..b52d684 100644
--- a/net/batman-adv/bat_v.c
+++ b/net/batman-adv/bat_v.c
@@ -265,14 +265,23 @@ 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,
@@ -282,17 +291,26 @@ 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);
-       ifinfo2 = batadv_neigh_ifinfo_get(neigh2, if_outgoing2);
+       if (WARN_ON(!ifinfo1))
+               goto err_ifinfo1;
 
-       if (WARN_ON(!ifinfo1 || !ifinfo2))
-               return false;
+       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 = {
-- 
2.8.1