From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: [PATCH net-next] net/ipv6: fix LOCKDEP issue in rt6_remove_exception_rt() Date: Tue, 24 Apr 2018 09:22:49 -0700 Message-ID: <20180424162249.41820-1-edumazet@google.com> Cc: netdev , Eric Dumazet , Eric Dumazet , David Ahern To: "David S . Miller" Return-path: Received: from mail-pg0-f68.google.com ([74.125.83.68]:46060 "EHLO mail-pg0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750729AbeDXQWy (ORCPT ); Tue, 24 Apr 2018 12:22:54 -0400 Received: by mail-pg0-f68.google.com with SMTP id i29so9724657pgn.12 for ; Tue, 24 Apr 2018 09:22:53 -0700 (PDT) Sender: netdev-owner@vger.kernel.org List-ID: rt6_remove_exception_rt() is called under rcu_read_lock() only. We lock rt6_exception_lock a bit later, so we do not hold rt6_exception_lock yet. Fixes: 8a14e46f1402 ("net/ipv6: Fix missing rcu dereferences on from") Signed-off-by: Eric Dumazet Reported-by: syzbot Cc: David Ahern --- net/ipv6/route.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/net/ipv6/route.c b/net/ipv6/route.c index ac3e51631c659b5c5c8a93c17011cb7f3ad266e2..432c4bcc1111085671f32987e4673e47898085a3 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -1546,8 +1546,7 @@ static int rt6_remove_exception_rt(struct rt6_info *rt) struct fib6_info *from; int err; - from = rcu_dereference_protected(rt->from, - lockdep_is_held(&rt6_exception_lock)); + from = rcu_dereference(rt->from); if (!from || !(rt->rt6i_flags & RTF_CACHE)) return -EINVAL; -- 2.17.0.484.g0c8726318c-goog