[PATCH 5.11 171/210] openvswitch: fix send of uninitialized stack memory in ct limit reply

Greg Kroah-Hartman
2021-04-12T09:43:29Z

From: Ilya Maximets <i.maximets@ovn.org>

[ Upstream commit 4d51419d49930be2701c2633ae271b350397c3ca ]

'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: 11efd5cb04a1 ("openvswitch: Support conntrack zone limit")
Signed-off-by: Ilya Maximets <i.maximets@ovn.org>
Acked-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/openvswitch/conntrack.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/net/openvswitch/conntrack.c b/net/openvswitch/conntrack.c
index 5eddfe7bd391..2316efd6ace8 100644
--- a/net/openvswitch/conntrack.c
+++ b/net/openvswitch/conntrack.c
@@ -2032,10 +2032,10 @@ 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);
}
--
2.30.2