From 8b2b5e27cae0bd2572687869111e516ab445be34 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Mon, 5 Aug 2013 11:18:49 -0700 Subject: [PATCH] fib_trie: remove potential out of bound access [ 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 Signed-off-by: Eric Dumazet Cc: Dmitry Vyukov Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/fib_trie.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c index 49616fed9340..6e8a13da6cbd 100644 --- a/net/ipv4/fib_trie.c +++ b/net/ipv4/fib_trie.c @@ -71,7 +71,6 @@ #include #include #include -#include #include #include #include @@ -1761,10 +1760,8 @@ static struct leaf *leaf_walk_rcu(struct tnode *p, struct rt_trie_node *c) 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; -- 2.34.1