From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932813AbbDNP4f (ORCPT ); Tue, 14 Apr 2015 11:56:35 -0400 Received: from bh-25.webhostbox.net ([208.91.199.152]:42226 "EHLO bh-25.webhostbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932193AbbDNP41 (ORCPT ); Tue, 14 Apr 2015 11:56:27 -0400 Date: Tue, 14 Apr 2015 08:55:24 -0700 From: Guenter Roeck To: Honggang Li Cc: roland@kernel.org, sean.hefty@intel.com, hal.rosenstock@gmail.com, kaber@trash.net, davem@davemloft.net, alex.estrin@intel.com, dledford@redhat.com, edumazet@google.com, erezsh@mellanox.com, nicolas.dichtel@6wind.com, maheshb@google.com, jbenc@redhat.com, ebiederm@xmission.com, elfring@users.sourceforge.net, f.fainelli@gmail.com, andrew@lunn.ch, sfeldma@gmail.com, alexander.h.duyck@intel.com, linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org Subject: Re: [PATCH linux-next 4/4] net/dsa: fix possible NULL pointer dereference in dsa_slave_get_iflink Message-ID: <20150414155524.GA18069@roeck-us.net> References: <1429024817-21561-1-git-send-email-honli@redhat.com> <1429024817-21561-5-git-send-email-honli@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1429024817-21561-5-git-send-email-honli@redhat.com> User-Agent: Mutt/1.5.23 (2014-03-12) X-Authenticated_sender: guenter@roeck-us.net X-OutGoing-Spam-Status: No, score=0.0 X-CTCH-PVer: 0000001 X-CTCH-Spam: Unknown X-CTCH-VOD: Unknown X-CTCH-Flags: 0 X-CTCH-RefID: str=0001.0A020203.552D38AB.0049,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0 X-CTCH-Score: 0.000 X-CTCH-ScoreCust: 0.000 X-CTCH-Rules: X-CTCH-SenderID: linux@roeck-us.net X-CTCH-SenderID-Flags: 0 X-CTCH-SenderID-TotalMessages: 21 X-CTCH-SenderID-TotalSpam: 0 X-CTCH-SenderID-TotalSuspected: 0 X-CTCH-SenderID-TotalConfirmed: 0 X-CTCH-SenderID-TotalBulk: 0 X-CTCH-SenderID-TotalVirus: 0 X-CTCH-SenderID-TotalRecipients: 0 X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - bh-25.webhostbox.net X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - roeck-us.net X-Get-Message-Sender-Via: bh-25.webhostbox.net: mailgid no entry from get_relayhosts_entry X-Source: X-Source-Args: X-Source-Dir: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 14, 2015 at 11:20:17PM +0800, Honggang Li wrote: > Signed-off-by: Honggang Li > --- > net/dsa/slave.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/net/dsa/slave.c b/net/dsa/slave.c > index 827cda56..070b599 100644 > --- a/net/dsa/slave.c > +++ b/net/dsa/slave.c > @@ -59,7 +59,10 @@ static int dsa_slave_get_iflink(const struct net_device *dev) > { > struct dsa_slave_priv *p = netdev_priv(dev); > > - return p->parent->dst->master_netdev->ifindex; > + if (p && p->parent && p->parent->dst && p->parent->dst->master_netdev) > + return p->parent->dst->master_netdev->ifindex; > + else > + return 0; > } I would expect some explanation why you believe that any of those pointers can be NULL. Guenter