From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Ahern Subject: Re: [Patch net] ipv6: fix double refcount of fib6_metrics Date: Sun, 12 Aug 2018 17:08:59 -0600 Message-ID: <30bcd6d8-e1ec-2cc3-8b2f-8a21ad4a529a@gmail.com> References: <20180803062038.13272-1-xiyou.wangcong@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Cc: Sabrina Dubroca To: Cong Wang , netdev@vger.kernel.org Return-path: Received: from mail-pf1-f196.google.com ([209.85.210.196]:40033 "EHLO mail-pf1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727943AbeHMBsg (ORCPT ); Sun, 12 Aug 2018 21:48:36 -0400 Received: by mail-pf1-f196.google.com with SMTP id e13-v6so6824439pff.7 for ; Sun, 12 Aug 2018 16:09:01 -0700 (PDT) In-Reply-To: <20180803062038.13272-1-xiyou.wangcong@gmail.com> Content-Language: en-US Sender: netdev-owner@vger.kernel.org List-ID: On 8/3/18 12:20 AM, Cong Wang wrote: > All the callers of ip6_rt_copy_init()/rt6_set_from() hold refcnt > of the "from" fib6_info, so there is no need to hold fib6_metrics > refcnt again, because fib6_metrics refcnt is only released when > fib6_info is gone, that is, they have the same life time, so the > whole fib6_metrics refcnt can be removed actually. > > This fixes a kmemleak warning reported by Sabrina. > > Fixes: 93531c674315 ("net/ipv6: separate handling of FIB entries from dst based routes") > Reported-by: Sabrina Dubroca > Cc: Sabrina Dubroca > Cc: David Ahern > Signed-off-by: Cong Wang > --- > net/ipv6/route.c | 4 ---- > 1 file changed, 4 deletions(-) > > diff --git a/net/ipv6/route.c b/net/ipv6/route.c > index ec18b3ce8b6d..7208c16302f6 100644 > --- a/net/ipv6/route.c > +++ b/net/ipv6/route.c > @@ -978,10 +978,6 @@ static void rt6_set_from(struct rt6_info *rt, struct fib6_info *from) > rt->rt6i_flags &= ~RTF_EXPIRES; > rcu_assign_pointer(rt->from, from); > dst_init_metrics(&rt->dst, from->fib6_metrics->metrics, true); > - if (from->fib6_metrics != &dst_default_metrics) { > - rt->dst._metrics |= DST_METRICS_REFCOUNTED; > - refcount_inc(&from->fib6_metrics->refcnt); > - } > } > > /* Caller must already hold reference to @ort */ > This seems like a reasonable fix. Thanks for the patch.