net/ipv6: update flowi6_oif in ip6_dst_lookup_flow if not set
Newly created flows don't have flowi6_oif set (at least if the
associated socket is not interface-bound). This leads to a mismatch in
__xfrm6_selector_match() for policies which specify an interface in the
selector (sel->ifindex != 0).
Backtracing shows this happens in code-paths originating from e.g.
ip6_datagram_connect(), rawv6_sendmsg() or tcp_v6_connect(). (UDP was
not tested for.)
In summary, this patch fixes policy matching on outgoing interface for
locally generated packets.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index d5f7716..c5fc852 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -1023,6 +1023,8 @@
return ERR_PTR(err);
if (final_dst)
fl6->daddr = *final_dst;
+ if (!fl6->flowi6_oif)
+ fl6->flowi6_oif = dst->dev->ifindex;
return xfrm_lookup_route(sock_net(sk), dst, flowi6_to_flowi(fl6), sk, 0);
}