[NETFILTER]: Fix bridge netfilter related in xfrm_lookup

The bridge-netfilter code attaches a fake dst_entry with dst->ops == NULL
to purely bridged packets. When these packets are SNATed and a policy
lookup is done, xfrm_lookup crashes because it tries to dereference
dst->ops.

Change xfrm_lookup not to dereference dst->ops before checking for the
DST_NOXFRM flag and set this flag in the fake dst_entry.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 0 deletions

diff --git a/net/bridge/br_netfilter.c b/net/bridge/br_netfilter.c
index 6bb0c7eb1ef0..e060aad8624d 100644
--- a/net/bridge/br_netfilter.c
+++ b/net/bridge/br_netfilter.c
@@ -90,6 +90,7 @@ static struct rtable __fake_rtable = {
                         .dev                    = &__fake_net_device,
                         .path                   = &__fake_rtable.u.dst,
                         .metrics                = {[RTAX_MTU - 1] = 1500},
+                        .flags                  = DST_NOXFRM,
                 }
         },
         .rt_flags       = 0,