From 3e9a34c67e5376bedd9e79e6a7e16b01a01c8215 Mon Sep 17 00:00:00 2001
From: Elena Reshetova <elena.reshetova@intel.com>
Date: Wed, 30 Aug 2017 13:55:54 +0300
Subject: [PATCH 153/194] net: mpls: prevent speculative execution

Since the index value in function mpls_route_input_rcu()
seems to be controllable by userspace and later on
conditionally (upon bound check) used to resolve
platform_label, insert an observable speculation
barrier before its usage. This should prevent
observable speculation on that branch and avoid
kernel memory leak.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
---
 net/mpls/af_mpls.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c
index c5b9ce4..3bdf8d8 100644
--- a/net/mpls/af_mpls.c
+++ b/net/mpls/af_mpls.c
@@ -50,6 +50,8 @@ static struct mpls_route *mpls_route_input_rcu(struct net *net, unsigned index)
 	if (index < net->mpls.platform_labels) {
 		struct mpls_route __rcu **platform_label =
 			rcu_dereference(net->mpls.platform_label);
+
+		osb();
 		rt = rcu_dereference(platform_label[index]);
 	}
 	return rt;
-- 
2.9.5