batman-adv: Ignore invalid batadv_iv_gw during netlink send

BugLink: http://bugs.launchpad.net/bugs/1786352
[ Upstream commit 10d570284258a30dc104c50787c5289ec49f3d23 ]

The function batadv_iv_gw_dump stops the processing loop when
batadv_iv_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: efb766af06e3 ("batman-adv: add B.A.T.M.A.N. IV 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>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

diff --git a/net/batman-adv/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c
index bbe8414b6ee7d21f86e5ab9302ebfc875dbe33d3..370642689145fa4d1fcd000b80d42c86f40f399d 100644 (file)
--- a/net/batman-adv/bat_iv_ogm.c
+++ b/net/batman-adv/bat_iv_ogm.c
@@ -2719,7 +2719,7 @@ static int batadv_iv_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);