4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: David Ahern <dsa@xxxxxxxxxxxxxxxxxxx> [ Upstream commit 2bd137de531367fb573d90150d1872cb2a2095f7 ] An error was reported upgrading to 4.9.8: root@Typhoon:~# ip route add default table 210 nexthop dev eth0 via 10.68.64.1 weight 1 nexthop dev eth0 via 10.68.64.2 weight 1 RTNETLINK answers: Operation not supported The problem occurs when CONFIG_LWTUNNEL is not enabled and a multipath route is submitted. The point of lwtunnel_valid_encap_type_attr is catch modules that need to be loaded before any references are taken with rntl held. With CONFIG_LWTUNNEL disabled, there will be no modules to load so the lwtunnel_valid_encap_type_attr stub should just return 0. Fixes: 9ed59592e3e3 ("lwtunnel: fix autoload of lwt modules") Reported-by: pupilla@xxxxxxxxx Signed-off-by: David Ahern <dsa@xxxxxxxxxxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- include/net/lwtunnel.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/include/net/lwtunnel.h +++ b/include/net/lwtunnel.h @@ -176,7 +176,10 @@ static inline int lwtunnel_valid_encap_t } static inline int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int len) { - return -EOPNOTSUPP; + /* return 0 since we are not walking attr looking for + * RTA_ENCAP_TYPE attribute on nexthops. + */ + return 0; } static inline int lwtunnel_build_state(struct net_device *dev, u16 encap_type,