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=-7.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=ham 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 D9346C3F68F for ; Thu, 26 Dec 2019 08:14:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A6DF72080D for ; Thu, 26 Dec 2019 08:14:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1577348072; bh=qAJJ9NMSnMVhCpLynoWz3P/v7ZgJJ0B3dmwBQ1oG2sc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=eEi5xce7li5Duxs/JJOy+dDKkJ5QxW3ykrDYjYK9S772a5HhIKqBx+avfI1P1ApFZ JSmgCazTIFAWPjEmuVLPA0JWabKPMqXYJsMMTVy4fUWXRBze/ZHiMWtWU18MXvw87e +QV2e4yKYe+gwPLrZldtNxCHRa89wScCKfpldQ78= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726406AbfLZIOb (ORCPT ); Thu, 26 Dec 2019 03:14:31 -0500 Received: from mail.kernel.org ([198.145.29.99]:58714 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725878AbfLZIOb (ORCPT ); Thu, 26 Dec 2019 03:14:31 -0500 Received: from localhost (unknown [193.47.165.251]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 706462071E; Thu, 26 Dec 2019 08:14:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1577348071; bh=qAJJ9NMSnMVhCpLynoWz3P/v7ZgJJ0B3dmwBQ1oG2sc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ZJ7LqB7wLtCMqLImbovnXckuN7Xxx9yWcIonPhExI2L2x0qPEMJbzSQcRWWqE5d5M QfPo5RqGjrRwj/mQEqne4dd3YdbcaKAAiLpQSCjTcGIvbo+mye/EkJ/gAaLEQMYsE6 Pm3wjUm5FMFCS0yXZLvnBr81g0VuuOreV5vEed6M= Date: Thu, 26 Dec 2019 10:14:27 +0200 From: Leon Romanovsky To: xiyuyang19@fudan.edu.cn Cc: yuanxzhang@fudan.edu.cn, kjlu@umn.edu, Xin Tan , Faisal Latif , Shiraz Saleem , Doug Ledford , Jason Gunthorpe , linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] infiniband: i40iw: fix a potential NULL pointer dereference Message-ID: <20191226081427.GA6285@unreal> References: <1577328772-14038-1-git-send-email-xiyuyang19@fudan.edu.cn> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1577328772-14038-1-git-send-email-xiyuyang19@fudan.edu.cn> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Dec 26, 2019 at 10:52:52AM +0800, xiyuyang19@fudan.edu.cn wrote: > From: Xiyu Yang > > in_dev_get may return a NULL object. The fix handles the situation > by adding a check to avoid NULL pointer dereference on idev, > as pick_local_ipaddrs does. > > Signed-off-by: Xiyu Yang > Signed-off-by: Xin Tan > --- > drivers/infiniband/hw/i40iw/i40iw_main.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/infiniband/hw/i40iw/i40iw_main.c b/drivers/infiniband/hw/i40iw/i40iw_main.c > index d44cf33d..18587cc 100644 > --- a/drivers/infiniband/hw/i40iw/i40iw_main.c > +++ b/drivers/infiniband/hw/i40iw/i40iw_main.c > @@ -1225,6 +1225,8 @@ static void i40iw_add_ipv4_addr(struct i40iw_device *iwdev) > const struct in_ifaddr *ifa; > > idev = in_dev_get(dev); > + if (!idev) > + return; 1. You forgot to release rtnl lock. 2. The rtnl_trylock()/rtnl_unlock() scheme is wrong in this function. That lock is global and any devices can take it and prevent from i40iw to success in rtnl_trylock(), after that in_dev_for_each_ifa_rtnl() will be incorrect. > in_dev_for_each_ifa_rtnl(ifa, idev) { > i40iw_debug(&iwdev->sc_dev, I40IW_DEBUG_CM, > "IP=%pI4, vlan_id=%d, MAC=%pM\n", &ifa->ifa_address, > -- > 2.7.4 >