Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932343AbbDOQHO (ORCPT ); Wed, 15 Apr 2015 12:07:14 -0400 Received: from quartz.orcorp.ca ([184.70.90.242]:51561 "EHLO quartz.orcorp.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754295AbbDOQHG (ORCPT ); Wed, 15 Apr 2015 12:07:06 -0400 Date: Wed, 15 Apr 2015 10:06:23 -0600 From: Jason Gunthorpe To: Erez Shitrit Cc: Honggang Li , Roland Dreier , sean.hefty@intel.com, hal.rosenstock@gmail.com, kaber@trash.net, davem@davemloft.net, Alex Estrin , Doug Ledford , edumazet@google.com, Erez Shitrit , nicolas.dichtel@6wind.com, maheshb@google.com, jbenc@redhat.com, ebiederm@xmission.com, elfring@users.sourceforge.net, f.fainelli@gmail.com, linux@roeck-us.net, 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 1/4] infiniband/ipoib: fix possible NULL pointer dereference in ipoib_get_iflink Message-ID: <20150415160623.GA4653@obsidianresearch.com> References: <1429024817-21561-1-git-send-email-honli@redhat.com> <1429024817-21561-2-git-send-email-honli@redhat.com> <20150414204133.GJ7682@obsidianresearch.com> <552E026A.4020200@dev.mellanox.co.il> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <552E026A.4020200@dev.mellanox.co.il> User-Agent: Mutt/1.5.21 (2010-09-15) X-Broken-Reverse-DNS: no host name found for IP address 10.0.0.183 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1997 Lines: 48 On Wed, Apr 15, 2015 at 09:17:14AM +0300, Erez Shitrit wrote: > >>+ /* parent interface */ > >>+ if (!test_bit(IPOIB_FLAG_SUBINTERFACE, &priv->flags)) > >>+ return dev->ifindex; > >>+ > >>+ /* child/vlan interface */ > >>+ if (!priv->parent) > >>+ return -1; > >Like was said for other drivers, I can't see how parent can be null > >while IPOIB_FLAG_SUBINTERFACE is set. Drop the last if. > It can, at least for ipoib child interface (AKA "vlan"), you can't > control the call for that ndo and it can be called before the parent > was set. If the ndo can be called before the netdev private structures are fully prepared then we have another bug, and returning -1 or 0 is not the right answer anyhow. For safety, fold this into your patch. diff --git a/drivers/infiniband/ulp/ipoib/ipoib_vlan.c b/drivers/infiniband/ulp/ipoib/ipoib_vlan.c index 9fad7b5ac8b9..e62b007adf5d 100644 --- a/drivers/infiniband/ulp/ipoib/ipoib_vlan.c +++ b/drivers/infiniband/ulp/ipoib/ipoib_vlan.c @@ -58,6 +58,7 @@ int __ipoib_vlan_add(struct ipoib_dev_priv *ppriv, struct ipoib_dev_priv *priv, /* MTU will be reset when mcast join happens */ priv->dev->mtu = IPOIB_UD_MTU(priv->max_ib_mtu); priv->mcast_mtu = priv->admin_mtu = priv->dev->mtu; + priv->parent = ppriv->dev; set_bit(IPOIB_FLAG_SUBINTERFACE, &priv->flags); result = ipoib_set_dev_features(priv, ppriv->ca); @@ -84,8 +85,6 @@ int __ipoib_vlan_add(struct ipoib_dev_priv *ppriv, struct ipoib_dev_priv *priv, goto register_failed; } - priv->parent = ppriv->dev; - ipoib_create_debug_files(priv->dev); /* RTNL childs don't need proprietary sysfs entries */ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/