[PATCH net] openvswitch: Fix flow lookup to use unmasked key

[Eelco Chaudron <echaudro@redhat.com>]

The commit mentioned below causes the ovs_flow_tbl_lookup() function
to be called with the masked key. However, it's supposed to be called
with the unmasked key.

This change reverses the commit below, but rather than having the key
on the stack, it's allocated.

Fixes: 190aa3e77880 ("openvswitch: Fix Frame-size larger than 1024 bytes warning.")

Signed-off-by: Eelco Chaudron <echaudro@redhat.com>
---
 net/openvswitch/datapath.c |   25 ++++++++++++++++---------
 1 file changed, 16 insertions(+), 9 deletions(-)

diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
index 861dfb8daf4a..23b233caa7fd 100644
--- a/net/openvswitch/datapath.c
+++ b/net/openvswitch/datapath.c
@@ -948,6 +948,7 @@ static int ovs_flow_cmd_new(struct sk_buff *skb, struct genl_info *info)
 	struct sw_flow_mask mask;
 	struct sk_buff *reply;
 	struct datapath *dp;
+	struct sw_flow_key *key;
 	struct sw_flow_actions *acts;
 	struct sw_flow_match match;
 	u32 ufid_flags = ovs_nla_get_ufid_flags(a[OVS_FLOW_ATTR_UFID_FLAGS]);
@@ -975,24 +976,26 @@ static int ovs_flow_cmd_new(struct sk_buff *skb, struct genl_info *info)
 	}
 
 	/* Extract key. */
-	ovs_match_init(&match, &new_flow->key, false, &mask);
+	key = kzalloc(sizeof(*key), GFP_KERNEL);
+	if (!key) {
+		error = -ENOMEN;
+		goto err_kfree_key;
+	}
+
+	ovs_match_init(&match, key, false, &mask);
 	error = ovs_nla_get_match(net, &match, a[OVS_FLOW_ATTR_KEY],
 				  a[OVS_FLOW_ATTR_MASK], log);
 	if (error)
 		goto err_kfree_flow;
 
+	ovs_flow_mask_key(&new_flow->key, key, true, &mask);
+
 	/* Extract flow identifier. */
 	error = ovs_nla_get_identifier(&new_flow->id, a[OVS_FLOW_ATTR_UFID],
-				       &new_flow->key, log);
+				       key, log);
 	if (error)
 		goto err_kfree_flow;
 
-	/* unmasked key is needed to match when ufid is not used. */
-	if (ovs_identifier_is_key(&new_flow->id))
-		match.key = new_flow->id.unmasked_key;
-
-	ovs_flow_mask_key(&new_flow->key, &new_flow->key, true, &mask);
-
 	/* Validate actions. */
 	error = ovs_nla_copy_actions(net, a[OVS_FLOW_ATTR_ACTIONS],
 				     &new_flow->key, &acts, log);
@@ -1019,7 +1022,7 @@ static int ovs_flow_cmd_new(struct sk_buff *skb, struct genl_info *info)
 	if (ovs_identifier_is_ufid(&new_flow->id))
 		flow = ovs_flow_tbl_lookup_ufid(&dp->table, &new_flow->id);
 	if (!flow)
-		flow = ovs_flow_tbl_lookup(&dp->table, &new_flow->key);
+		flow = ovs_flow_tbl_lookup(&dp->table, key);
 	if (likely(!flow)) {
 		rcu_assign_pointer(new_flow->sf_acts, acts);
 
@@ -1089,6 +1092,8 @@ static int ovs_flow_cmd_new(struct sk_buff *skb, struct genl_info *info)
 
 	if (reply)
 		ovs_notify(&dp_flow_genl_family, reply, info);
+
+	kfree(key);
 	return 0;
 
 err_unlock_ovs:
@@ -1098,6 +1103,8 @@ static int ovs_flow_cmd_new(struct sk_buff *skb, struct genl_info *info)
 	ovs_nla_free_flow_actions(acts);
 err_kfree_flow:
 	ovs_flow_free(new_flow, false);
+err_kfree_key:
+	kfree(key);
 error:
 	return error;
 }