From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751985AbcEQViA (ORCPT ); Tue, 17 May 2016 17:38:00 -0400 Received: from mout.gmx.net ([212.227.17.21]:65002 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751053AbcEQVh7 (ORCPT ); Tue, 17 May 2016 17:37:59 -0400 Subject: Re: [PATCH 1/1] net: thunderx: avoid null pointer dereference To: David Daney References: <1463514038-9008-1-git-send-email-xypron.glpk@gmx.de> <573B7D39.9050305@caviumnetworks.com> Cc: Sunil Goutham , Robert Richter , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org From: Heinrich Schuchardt X-Enigmail-Draft-Status: N1110 Message-ID: <573B8F07.6080600@gmx.de> Date: Tue, 17 May 2016 23:37:11 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Icedove/38.8.0 MIME-Version: 1.0 In-Reply-To: <573B7D39.9050305@caviumnetworks.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-Provags-ID: V03:K0:pQ3cuHPRGfWsgg6LSzi4EHtry6BOdfr8UJEnszGeJR3PqoYoGe3 9G/mMmdkfTLxKp5pII+mCjoODAASWz8XlkwgpEt9O/HLNRWffFhpFb17Zw1GEVvQxPYDzsR j3OrZNo9xEy6mj1ZKm47Mf5RRB30p3UeUv6ZjKDIWCrUsSyTi0oIljUiHC8irq2Y+1dbF6w 6EVVhPGfOiu6KI2rZSayg== X-UI-Out-Filterresults: notjunk:1;V01:K0:aWXCe+5elDs=:3+FNR2d1RNWbHx6VzGF5V/ PjYVhRsiRh7of4FXr52NbjD1greBCv81UPCKJ0wPLaBnTYfeZFJlswQdCuzRBshyShYmAXZpq IgXoLr8wYtefc40qExipC3M5AbyNHOeAamm1zI3iqDYQydl3Y148PvUoQaGbdOq2MxAWt6OzM xKozoq9J0pijiWX+Do+i5DhaWjOOyOjye+L1xCLKlvkTlOrXdl2vWvrlfQcGnn/iInNpSOF28 +Vxnb1SkWkx3lYl5MKZJLd6iVZvhVpAQAMwekuOFEwii/WyNOyAc9IQhaO2R7sOS8deKnZiLB 6PY609wDx3yUYA/6YTPs7N6pypvR7iKigPzfVgbjGRzZi3J6yEoF8xncuB20hQkNofR2E3x2y /Pz+6/fKvXmKnrbH9PVF17RgMmcsKQoXH3MGczLBzY6qV8L/d7Bl5ge7HHOfrO1iXemY0ENPa IhVntSer/tWCO/5ysQXIIhqHznchJkjDUID1T3ekaSL7TauzGxP7A0TeQ2raVq/7LXk9vRkV0 uc0pAGrXPBG7P4JNihnHqzM/LbOxLVJgS+4h2JzA2zLRx4U1eTyAdBToA2HV+0hDecDFe12aR k0frD/URovnCMku1LqbOtCYfbMrnKsK1sMOAIo2+jyGe2kDnv5WA0NyW1SK8HhFfp2Q8OmsJj x/oWvTRiLUPSQjRcu0HKo9h2T+UXTez2qrOcn1oS3A2pCN1bL7SDy2i4zwvNUdoX2JQ/70EEA SVFAhp0B7xmLT6HtYO2rlzfvpAjvhAZvk7GIwf2V/uesxQqcYtrqFCqH14CCuEuQY1TZgrVQ7 uepAWb0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/17/2016 10:21 PM, David Daney wrote: > On 05/17/2016 12:40 PM, Heinrich Schuchardt wrote: >> In function bgx_lmac_handler only use a member of >> lmac after checking it is not null. >> > > Were you seeing and actual OOPs, or is this only a theoretical problem > flagged by some sort of static code checker? Cppcheck identified the code inconsistency. If the struct netdev * parameter cannot be NULL, you could eliminate the check. Other drivers do no have check against a NULL parameter in the adjust_link handler function (e.g. bgmac_adjust_link, pxa168_eth_adjust_link). Best regards Heinrich > >> Signed-off-by: Heinrich Schuchardt > > In any event, it seems sane to make this change, so: > > Acked-by: David Daney > > >> --- >> drivers/net/ethernet/cavium/thunder/thunder_bgx.c | 4 +++- >> 1 file changed, 3 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/net/ethernet/cavium/thunder/thunder_bgx.c >> b/drivers/net/ethernet/cavium/thunder/thunder_bgx.c >> index d20539a..3ed2198 100644 >> --- a/drivers/net/ethernet/cavium/thunder/thunder_bgx.c >> +++ b/drivers/net/ethernet/cavium/thunder/thunder_bgx.c >> @@ -274,12 +274,14 @@ static void bgx_sgmii_change_link_state(struct >> lmac *lmac) >> static void bgx_lmac_handler(struct net_device *netdev) >> { >> struct lmac *lmac = container_of(netdev, struct lmac, netdev); >> - struct phy_device *phydev = lmac->phydev; >> + struct phy_device *phydev; >> int link_changed = 0; >> >> if (!lmac) >> return; >> >> + phydev = lmac->phydev; >> + >> if (!phydev->link && lmac->last_link) >> link_changed = -1; >> >> > >