net: flow_dissector: fix thoff for IPPROTO_AH

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@google.com>
Cc: Daniel Borkmann <dborkman@redhat.com>
Cc: Nikolay Aleksandrov <nikolay@redhat.com>
Acked-by: Nikolay Aleksandrov <nikolay@redhat.com>
Acked-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 2 deletions

diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
index 1929af87b260..8d7d0dd72db2 100644
--- a/net/core/flow_dissector.c
+++ b/net/core/flow_dissector.c
@@ -154,8 +154,8 @@ 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;
         }