net: Copy inner L3 and L4 headers as unaligned on GRE TEB

[ Upstream commit 78565208d73ca9b654fb9a6b142214d52eeedfd1 ]

This patch corrects the unaligned accesses seen on GRE TEB tunnels when
generating hash keys.  Specifically what this patch does is make it so that
we force the use of skb_copy_bits when the GRE inner headers will be
unaligned due to NET_IP_ALIGNED being a non-zero value.

Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
Acked-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
index d79699c9d1b9eb9f250254e360b2d5a7b4ff6e34..b258f457dac88372e208f1a2830560aa9bbbbc59 100644 (file)
--- a/net/core/flow_dissector.c
+++ b/net/core/flow_dissector.c
@@ -396,6 +396,13 @@ ip_proto_again:
                                goto out_bad;
                        proto = eth->h_proto;
                        nhoff += sizeof(*eth);
+
+                       /* Cap headers that we access via pointers at the
+                        * end of the Ethernet header as our maximum alignment
+                        * at that point is only 2 bytes.
+                        */
+                       if (NET_IP_ALIGN)
+                               hlen = nhoff;
                }
 
                key_control->flags |= FLOW_DIS_ENCAPSULATION;