openvswitch: Preallocate reply skb in ovs_vport_cmd_set().
Allocation of the Netlink notification skb can potentially fail
after changing vport configuration. In general, we try to avoid
this by undoing any change we made but that is difficult for existing
objects. This avoids the problem by preallocating the buffer (which
is fixed size).
Signed-off-by: Jesse Gross <jesse@nicira.com>
diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
index a4b7247..6980c3e6 100644
--- a/net/openvswitch/datapath.c
+++ b/net/openvswitch/datapath.c
@@ -1593,10 +1593,8 @@
return ERR_PTR(-ENOMEM);
retval = ovs_vport_cmd_fill_info(vport, skb, portid, seq, 0, cmd);
- if (retval < 0) {
- kfree_skb(skb);
- return ERR_PTR(retval);
- }
+ BUG_ON(retval < 0);
+
return skb;
}
@@ -1726,24 +1724,32 @@
nla_get_u32(a[OVS_VPORT_ATTR_TYPE]) != vport->ops->type)
err = -EINVAL;
+ reply = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+ if (!reply) {
+ err = -ENOMEM;
+ goto exit_unlock;
+ }
+
if (!err && a[OVS_VPORT_ATTR_OPTIONS])
err = ovs_vport_set_options(vport, a[OVS_VPORT_ATTR_OPTIONS]);
if (err)
- goto exit_unlock;
+ goto exit_free;
+
if (a[OVS_VPORT_ATTR_UPCALL_PID])
vport->upcall_portid = nla_get_u32(a[OVS_VPORT_ATTR_UPCALL_PID]);
- reply = ovs_vport_cmd_build_info(vport, info->snd_portid, info->snd_seq,
- OVS_VPORT_CMD_NEW);
- if (IS_ERR(reply)) {
- netlink_set_err(sock_net(skb->sk)->genl_sock, 0,
- ovs_dp_vport_multicast_group.id, PTR_ERR(reply));
- goto exit_unlock;
- }
+ err = ovs_vport_cmd_fill_info(vport, reply, info->snd_portid,
+ info->snd_seq, 0, OVS_VPORT_CMD_NEW);
+ BUG_ON(err < 0);
genl_notify(reply, genl_info_net(info), info->snd_portid,
ovs_dp_vport_multicast_group.id, info->nlhdr, GFP_KERNEL);
+ rtnl_unlock();
+ return 0;
+
+exit_free:
+ kfree_skb(reply);
exit_unlock:
rtnl_unlock();
return err;