From: David Ahern <dsahern@xxxxxxxxxx> [ Upstream commit 874fb9e2ca949b443cc419a4f2227cafd4381d39 ] Tobias reported regressions in IPsec tests following the patch referenced by the Fixes tag below. The root cause is dropping the reset of the flowi4_oif after the fib_lookup. Apparently it is needed for xfrm cases, so restore the oif update to ip_route_output_flow right before the call to xfrm_lookup_route. Fixes: 2fbc6e89b2f1 ("ipv4: Update exception handling for multipath routes via same device") Reported-by: Tobias Brunner <tobias@xxxxxxxxxxxxxx> Signed-off-by: David Ahern <dsahern@xxxxxxxxxx> Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/ipv4/route.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -2764,10 +2764,12 @@ struct rtable *ip_route_output_flow(stru if (IS_ERR(rt)) return rt; - if (flp4->flowi4_proto) + if (flp4->flowi4_proto) { + flp4->flowi4_oif = rt->dst.dev->ifindex; rt = (struct rtable *)xfrm_lookup_route(net, &rt->dst, flowi4_to_flowi(flp4), sk, 0); + } return rt; }