Subject: [PATCH 15/18] openvswitch: Prevent kernel-infoleak in ovs_ct_put_key()

From: Peilin Ye <[email-masked]>
Date: Fri, 31 Jul 2020 00:48:38 -0400

[ Upstream commit 9aba6c5b49254d5bee927d81593ed4429e91d4ae ]

ovs_ct_put_key() is potentially copying uninitialized kernel stack memory
into socket buffers, since the compiler may leave a 3-byte hole at the end
of `struct ovs_key_ct_tuple_ipv4` and `struct ovs_key_ct_tuple_ipv6`. Fix
it by initializing `orig` with memset().

Fixes: 9dd7f8907c37 ("openvswitch: Add original direction conntrack tuple to sw_flow_key.")
Suggested-by: Dan Carpenter <[email-masked]>
Signed-off-by: Peilin Ye <[email-masked]>
Signed-off-by: David S. Miller <[email-masked]>
---
 net/openvswitch/conntrack.c | 38 +++++++++++++++++++------------------
 1 file changed, 20 insertions(+), 18 deletions(-)

diff --git a/net/openvswitch/conntrack.c b/net/openvswitch/conntrack.c
index 8b70298857e3..c86e404cd65b 100644
--- a/net/openvswitch/conntrack.c
+++ b/net/openvswitch/conntrack.c
@@ -276,10 +276,6 @@ void ovs_ct_fill_key(const struct sk_buff *skb, struct sw_flow_key *key)
 	ovs_ct_update_key(skb, NULL, key, false, false);
 }
 
-#define IN6_ADDR_INITIALIZER(ADDR) \
-	{ (ADDR).s6_addr32[0], (ADDR).s6_addr32[1], \
-	  (ADDR).s6_addr32[2], (ADDR).s6_addr32[3] }
-
 int ovs_ct_put_key(const struct sw_flow_key *swkey,
 		   const struct sw_flow_key *output, struct sk_buff *skb)
 {
@@ -301,24 +297,30 @@ int ovs_ct_put_key(const struct sw_flow_key *swkey,
 
 	if (swkey->ct_orig_proto) {
 		if (swkey->eth.type == htons(ETH_P_IP)) {
-			struct ovs_key_ct_tuple_ipv4 orig = {
-				output->ipv4.ct_orig.src,
-				output->ipv4.ct_orig.dst,
-				output->ct.orig_tp.src,
-				output->ct.orig_tp.dst,
-				output->ct_orig_proto,
-			};
+			struct ovs_key_ct_tuple_ipv4 orig;
+
+			memset(&orig, 0, sizeof(orig));
+			orig.ipv4_src = output->ipv4.ct_orig.src;
+			orig.ipv4_dst = output->ipv4.ct_orig.dst;
+			orig.src_port = output->ct.orig_tp.src;
+			orig.dst_port = output->ct.orig_tp.dst;
+			orig.ipv4_proto = output->ct_orig_proto;
+
 			if (nla_put(skb, OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV4,
 				    sizeof(orig), &orig))
 				return -EMSGSIZE;
 		} else if (swkey->eth.type == htons(ETH_P_IPV6)) {
-			struct ovs_key_ct_tuple_ipv6 orig = {
-				IN6_ADDR_INITIALIZER(output->ipv6.ct_orig.src),
-				IN6_ADDR_INITIALIZER(output->ipv6.ct_orig.dst),
-				output->ct.orig_tp.src,
-				output->ct.orig_tp.dst,
-				output->ct_orig_proto,
-			};
+			struct ovs_key_ct_tuple_ipv6 orig;
+
+			memset(&orig, 0, sizeof(orig));
+			memcpy(orig.ipv6_src, output->ipv6.ct_orig.src.s6_addr32,
+			       sizeof(orig.ipv6_src));
+			memcpy(orig.ipv6_dst, output->ipv6.ct_orig.dst.s6_addr32,
+			       sizeof(orig.ipv6_dst));
+			orig.src_port = output->ct.orig_tp.src;
+			orig.dst_port = output->ct.orig_tp.dst;
+			orig.ipv6_proto = output->ct_orig_proto;
+
 			if (nla_put(skb, OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV6,
 				    sizeof(orig), &orig))
 				return -EMSGSIZE;
-- 
2.26.2