batman-adv: Use kref_get for batadv_tvlv_container_get

batadv_tvlv_container_get requires that tvlv.container_list_lock is held by
the caller. It is therefore not possible that an item in
tvlv.container_list has an reference counter of 0 and is still in the list

The kref_get function instead WARNs (with debug information) when the
reference counter would still be 0. This makes a bug in batman-adv better
visible because kref_get_unless_zero would have ignored this problem.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <a@unstable.cc>

diff --git a/net/batman-adv/main.c b/net/batman-adv/main.c
index c8d8bc78a518e6be6c9825dfb592c5769062f588..5f2974bd1227f32301dc607039d3271add649281 100644 (file)
--- a/net/batman-adv/main.c
+++ b/net/batman-adv/main.c
@@ -748,9 +748,7 @@ batadv_tvlv_container_get(struct batadv_priv *bat_priv, u8 type, u8 version)
                if (tvlv_tmp->tvlv_hdr.version != version)
                        continue;
 
-               if (!kref_get_unless_zero(&tvlv_tmp->refcount))
-                       continue;
-
+               kref_get(&tvlv_tmp->refcount);
                tvlv = tvlv_tmp;
                break;
        }