batman-adv: Ignore invalid batadv_v_gw during netlink send

[ Upstream commit 011c935fceae5252619ef730baa610c655281dda ]

The function batadv_v_gw_dump stops the processing loop when
batadv_v_gw_dump_entry returns a non-0 return code. This should only
happen when the buffer is full. Otherwise, an empty message may be
returned by batadv_gw_dump. This empty message will then stop the netlink
dumping of gateway entries. At worst, not a single entry is returned to
userspace even when plenty of possible gateways exist.

Fixes: b71bb6f924fe ("batman-adv: add B.A.T.M.A.N. V bat_gw_dump implementations")
Signed-off-by: Sven Eckelmann <sven.eckelmann@openmesh.com>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/batman-adv/bat_v.c b/net/batman-adv/bat_v.c
index e79f6f01182eb6731927aea1bc0cba553fb600ff..ed4ddf2059a61c3ec01f209cee23ae58a5c987ce 100644 (file)
--- a/net/batman-adv/bat_v.c
+++ b/net/batman-adv/bat_v.c
@@ -920,7 +920,7 @@ static int batadv_v_gw_dump_entry(struct sk_buff *msg, u32 portid, u32 seq,
        struct batadv_neigh_ifinfo *router_ifinfo = NULL;
        struct batadv_neigh_node *router;
        struct batadv_gw_node *curr_gw;
-       int ret = -EINVAL;
+       int ret = 0;
        void *hdr;
 
        router = batadv_orig_router_get(gw_node->orig_node, BATADV_IF_DEFAULT);