datapath: Fix template leak in error cases.

Upstream commit:
    openvswitch: Fix template leak in error cases.

    Commit 2f3ab9f9fc23 ("openvswitch: Fix helper reference leak") fixed a
    reference leak on helper objects, but inadvertently introduced a leak on
    the ct template.

    Previously, ct_info.ct->general.use was initialized to 0 by
    nf_ct_tmpl_alloc() and only incremented when ovs_ct_copy_action()
    returned successful. If an error occurred while adding the helper or
    adding the action to the actions buffer, the __ovs_ct_free_action()
    cleanup would use nf_ct_put() to free the entry; However, this relies on
    atomic_dec_and_test(ct_info.ct->general.use). This reference must be
    incremented first, or nf_ct_put() will never free it.

    Fix the issue by acquiring a reference to the template immediately after
    allocation.

    Fixes: cae3a2627520 ("openvswitch: Allow attaching helpers to ct action")
    Fixes: 2f3ab9f9fc23 ("openvswitch: Fix helper reference leak")
    Signed-off-by: Joe Stringer <[email protected]>
    Signed-off-by: David S. Miller <[email protected]>

Upstream: 90c7afc96cbb ("openvswitch: Fix template leak in error cases.")
Fixes: 11251c1 ("datapath: Allow attaching helpers to ct action")
Signed-off-by: Joe Stringer <[email protected]>
Acked-by: Jesse Gross <[email protected]>

datapath/conntrack.c

@@ -695,6 +695,10 @@ int ovs_ct_copy_action(struct net *net, const struct nlattr *attr,
 		OVS_NLERR(log, "Failed to allocate conntrack template");
 		return -ENOMEM;
 	}
+
+	__set_bit(IPS_CONFIRMED_BIT, &ct_info.ct->status);
+	nf_conntrack_get(&ct_info.ct->ct_general);
+
 	if (helper) {
 		err = ovs_ct_add_helper(&ct_info, helper, key, log);
 		if (err)
@@ -706,8 +710,6 @@ int ovs_ct_copy_action(struct net *net, const struct nlattr *attr,
 	if (err)
 		goto err_free_ct;
 
-	__set_bit(IPS_CONFIRMED_BIT, &ct_info.ct->status);
-	nf_conntrack_get(&ct_info.ct->ct_general);
 	return 0;
 err_free_ct:
 	__ovs_ct_free_action(&ct_info);