openvswitch: fix send of uninitialized stack memory in ct limit reply

stable inclusion
from stable-5.10.30
commit cc5418973cc9943c276a5ffef645a20f0aadf596
bugzilla: 51791

--------------------------------

[ Upstream commit 4d51419d ]

'struct ovs_zone_limit' has more members than initialized in
ovs_ct_limit_get_default_limit().  The rest of the memory is a random
kernel stack content that ends up being sent to userspace.

Fix that by using designated initializer that will clear all
non-specified fields.

Fixes: 11efd5cb ("openvswitch: Support conntrack zone limit")
Signed-off-by: NIlya Maximets <i.maximets@ovn.org>
Acked-by: NTonghao Zhang <xiangxia.m.yue@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Acked-by: N  Weilong Chen <chenweilong@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

net/openvswitch/conntrack.c

@@ -2024,10 +2024,10 @@ static int ovs_ct_limit_del_zone_limit(struct nlattr *nla_zone_limit,
 static int ovs_ct_limit_get_default_limit(struct ovs_ct_limit_info *info,
 					  struct sk_buff *reply)
 {
-	struct ovs_zone_limit zone_limit;
-
-	zone_limit.zone_id = OVS_ZONE_LIMIT_DEFAULT_ZONE;
-	zone_limit.limit = info->default_limit;
+	struct ovs_zone_limit zone_limit = {
+		.zone_id = OVS_ZONE_LIMIT_DEFAULT_ZONE,
+		.limit   = info->default_limit,
+	};
 
 	return nla_put_nohdr(reply, sizeof(zone_limit), &zone_limit);
 }