diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c index 82309efd417e..e4878e9aa636 100644 --- a/net/ipv4/ip_gre.c +++ b/net/ipv4/ip_gre.c @@ -1464,6 +1464,12 @@ static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[], if (!rtnl_dev_link_net_capable(dev, t->net)) return -EPERM; + if (data && data[IFLA_GRE_COLLECT_METADATA] && !t->collect_md) { + NL_SET_ERR_MSG(extack, + "Enabling collect_md on an existing device is not supported"); + return -EOPNOTSUPP; + } + err = ipgre_newlink_encap_setup(dev, data); if (err) return err; @@ -1496,6 +1502,12 @@ static int erspan_changelink(struct net_device *dev, struct nlattr *tb[], if (!rtnl_dev_link_net_capable(dev, t->net)) return -EPERM; + if (data && data[IFLA_GRE_COLLECT_METADATA] && !t->collect_md) { + NL_SET_ERR_MSG(extack, + "Enabling collect_md on an existing device is not supported"); + return -EOPNOTSUPP; + } + err = ipgre_newlink_encap_setup(dev, data); if (err) return err;