netfilter: flowtable: fix missing FLOWI_FLAG_ANYSRC flag

The nf_flow_table gets route through ip_route_output_key. If the saddr
is not local one, then FLOWI_FLAG_ANYSRC flag should be set. Without
this flag, the route lookup for other_dst will fail.

Fixes: 3412e164 (netfilter: flowtable: nft_flow_route use more data for reverse route)
Signed-off-by: wenxu <wenxu@chinatelecom.cn>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/nft_flow_offload.c

@@ -237,6 +237,7 @@ static int nft_flow_route(const struct nft_pktinfo *pkt,
 		fl.u.ip4.flowi4_iif = this_dst->dev->ifindex;
 		fl.u.ip4.flowi4_tos = RT_TOS(ip_hdr(pkt->skb)->tos);
 		fl.u.ip4.flowi4_mark = pkt->skb->mark;
+		fl.u.ip4.flowi4_flags = FLOWI_FLAG_ANYSRC;
 		break;
 	case NFPROTO_IPV6:
 		fl.u.ip6.daddr = ct->tuplehash[dir].tuple.src.u3.in6;
@@ -245,6 +246,7 @@ static int nft_flow_route(const struct nft_pktinfo *pkt,
 		fl.u.ip6.flowi6_iif = this_dst->dev->ifindex;
 		fl.u.ip6.flowlabel = ip6_flowinfo(ipv6_hdr(pkt->skb));
 		fl.u.ip6.flowi6_mark = pkt->skb->mark;
+		fl.u.ip6.flowi6_flags = FLOWI_FLAG_ANYSRC;
 		break;
 	}