From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Andrey Konovalov , Eric Dumazet , Dmitry Vyukov , "David S. Miller" Subject: [ 05/23] fib_trie: remove potential out of bound access Date: Thu, 12 Sep 2013 10:45:01 -0700 Message-Id: <20130912174452.354632606@linuxfoundation.org> In-Reply-To: <20130912174451.748805761@linuxfoundation.org> References: <20130912174451.748805761@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ 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(-) --- a/net/ipv4/fib_trie.c +++ b/net/ipv4/fib_trie.c @@ -71,7 +71,6 @@ #include #include #include -#include #include #include #include @@ -1772,10 +1771,8 @@ 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;