From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7431DC48BE8 for ; Tue, 15 Jun 2021 08:33:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 572B8613D0 for ; Tue, 15 Jun 2021 08:33:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231252AbhFOIf6 (ORCPT ); Tue, 15 Jun 2021 04:35:58 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:50875 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231241AbhFOIfo (ORCPT ); Tue, 15 Jun 2021 04:35:44 -0400 Received: from 1.general.cking.uk.vpn ([10.172.193.212]) by youngberry.canonical.com with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.93) (envelope-from ) id 1lt4Vs-00013n-RL; Tue, 15 Jun 2021 08:33:36 +0000 Subject: Re: [PATCH] net: dsa: b53: Fix dereference of null dev To: Dan Carpenter Cc: Florian Fainelli , Andrew Lunn , Vivien Didelot , Vladimir Oltean , "David S . Miller" , Jakub Kicinski , netdev@vger.kernel.org, kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org References: <20210612144407.60259-1-colin.king@canonical.com> <20210614112812.GL1955@kadam> From: Colin Ian King Message-ID: <60c9a7c8-95f1-2673-abd0-73853483acb0@canonical.com> Date: Tue, 15 Jun 2021 09:33:36 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <20210614112812.GL1955@kadam> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 14/06/2021 12:28, Dan Carpenter wrote: > On Sat, Jun 12, 2021 at 03:44:07PM +0100, Colin King wrote: >> From: Colin Ian King >> >> Currently pointer priv is dereferencing dev before dev is being null >> checked so a potential null pointer dereference can occur. Fix this >> by only assigning and using priv if dev is not-null. >> >> Addresses-Coverity: ("Dereference before null check") >> Fixes: 16994374a6fc ("net: dsa: b53: Make SRAB driver manage port interrupts") >> Signed-off-by: Colin Ian King >> --- >> drivers/net/dsa/b53/b53_srab.c | 8 +++++--- >> 1 file changed, 5 insertions(+), 3 deletions(-) >> >> diff --git a/drivers/net/dsa/b53/b53_srab.c b/drivers/net/dsa/b53/b53_srab.c >> index aaa12d73784e..e77ac598f859 100644 >> --- a/drivers/net/dsa/b53/b53_srab.c >> +++ b/drivers/net/dsa/b53/b53_srab.c >> @@ -629,11 +629,13 @@ static int b53_srab_probe(struct platform_device *pdev) >> static int b53_srab_remove(struct platform_device *pdev) >> { >> struct b53_device *dev = platform_get_drvdata(pdev); >> - struct b53_srab_priv *priv = dev->priv; >> >> - b53_srab_intr_set(priv, false); >> - if (dev) >> + if (dev) { > > This is the remove function and "dev" can't be NULL at this point. > Better to just remove the NULL check. Will do. > > regards, > dan carpenter >