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

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

From: Eric Dumazet <eduma...@google.com>

[ Upstream commit aab515d7c32a34300312416c50314e755ea6f765 ]

AddressSanitizer [1] dynamic checker pointed a potential
out of bound access in leaf_walk_rcu()

We could allocate one more slot in tnode_new() to leave the prefetch()
in-place but it looks not worth the pain.

Bug added in commit 82cfbb008572b ("[IPV4] fib_trie: iterator recode")

[1] :
https://code.google.com/p/address-sanitizer/wiki/AddressSanitizerForKernel

Reported-by: Andrey Konovalov <andreyk...@google.com>
Signed-off-by: Eric Dumazet <eduma...@google.com>
Cc: Dmitry Vyukov <dvyu...@google.com>
Signed-off-by: David S. Miller <da...@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
 net/ipv4/fib_trie.c |    5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -71,7 +71,6 @@
 #include <linux/init.h>
 #include <linux/list.h>
 #include <linux/slab.h>
-#include <linux/prefetch.h>
 #include <linux/export.h>
 #include <net/net_namespace.h>
 #include <net/ip.h>
@@ -1761,10 +1760,8 @@ static struct leaf *leaf_walk_rcu(struct
                        if (!c)
                                continue;
 
-                       if (IS_LEAF(c)) {
-                               prefetch(rcu_dereference_rtnl(p->child[idx]));
+                       if (IS_LEAF(c))
                                return (struct leaf *) c;
-                       }
 
                        /* Rescan start scanning in new node */
                        p = (struct tnode *) c;


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