[PATCH 060/100] net: flow_dissector: fix thoff for IPPROTO_AH

[Luis Henriques]

3.5.7.23 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Eric Dumazet <edumazet at google.com>

commit b86783587b3d1d552326d955acee37eac48800f1 upstream.

In commit 8ed781668dd49 ("flow_keys: include thoff into flow_keys for
later usage"), we missed that existing code was using nhoff as a
temporary variable that could not always contain transport header
offset.

This is not a problem for TCP/UDP because port offset (@poff)
is 0 for these protocols.

Signed-off-by: Eric Dumazet <edumazet at google.com>
Cc: Daniel Borkmann <dborkman at redhat.com>
Cc: Nikolay Aleksandrov <nikolay at redhat.com>
Acked-by: Nikolay Aleksandrov <nikolay at redhat.com>
Acked-by: Daniel Borkmann <dborkman at redhat.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 net/core/flow_dissector.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
index a225089..2774788 100644
--- a/net/core/flow_dissector.c
+++ b/net/core/flow_dissector.c
@@ -133,8 +133,8 @@ ipv6:
 	if (poff >= 0) {
 		__be32 *ports, _ports;
 
-		nhoff += poff;
-		ports = skb_header_pointer(skb, nhoff, sizeof(_ports), &_ports);
+		ports = skb_header_pointer(skb, nhoff + poff,
+					   sizeof(_ports), &_ports);
 		if (ports)
 			flow->ports = *ports;
 	}
-- 
1.8.3.2