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,URIBL_BLOCKED, 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 80490C43461 for ; Thu, 15 Apr 2021 14:09:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 657DB6100C for ; Thu, 15 Apr 2021 14:09:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233380AbhDOOKS (ORCPT ); Thu, 15 Apr 2021 10:10:18 -0400 Received: from mga03.intel.com ([134.134.136.65]:62047 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230056AbhDOOKQ (ORCPT ); Thu, 15 Apr 2021 10:10:16 -0400 IronPort-SDR: tjWuhqocqVlRaGKm8UG+L0A35L8TSR9RZ0LNgX+gR3OX27Yhh/uncvYoOshBFuuwsiTE1KQbwr RpuHrtPVG8Sg== X-IronPort-AV: E=McAfee;i="6200,9189,9955"; a="194885666" X-IronPort-AV: E=Sophos;i="5.82,225,1613462400"; d="scan'208";a="194885666" Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Apr 2021 07:09:41 -0700 IronPort-SDR: 31qFUbJplDmJcJwbCE3slOYca0ZnN/+3E7vaX73S8oZ8hG759bsYGZty0n8AJ9jl8jJYrGaPv3 7pDU1oWPxbQw== X-IronPort-AV: E=Sophos;i="5.82,225,1613462400"; d="scan'208";a="461627273" Received: from ckgurumu-mobl3.amr.corp.intel.com (HELO [10.212.35.10]) ([10.212.35.10]) by orsmga001-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Apr 2021 07:09:41 -0700 Subject: Re: [PATCH] dmaengine: idxd: Fix potential null dereference on pointer status To: Colin King , Vinod Koul , dmaengine@vger.kernel.org Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org References: <20210415110654.1941580-1-colin.king@canonical.com> From: Dave Jiang Message-ID: <4e545597-8fe5-411d-6bb7-0c5e8eea5b23@intel.com> Date: Thu, 15 Apr 2021 07:09:40 -0700 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.9.0 MIME-Version: 1.0 In-Reply-To: <20210415110654.1941580-1-colin.king@canonical.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 4/15/2021 4:06 AM, Colin King wrote: > From: Colin Ian King > > There are calls to idxd_cmd_exec that pass a null status pointer however > a recent commit has added an assignment to *status that can end up > with a null pointer dereference. The function expects a null status > pointer sometimes as there is a later assignment to *status where > status is first null checked. Fix the issue by null checking status > before making the assignment. > > Addresses-Coverity: ("Explicit null dereferenced") > Fixes: 89e3becd8f82 ("dmaengine: idxd: check device state before issue command") > Signed-off-by: Colin Ian King Acked-by: Dave Jiang Thanks! > --- > drivers/dma/idxd/device.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/dma/idxd/device.c b/drivers/dma/idxd/device.c > index 31c819544a22..78d2dc5e9bd8 100644 > --- a/drivers/dma/idxd/device.c > +++ b/drivers/dma/idxd/device.c > @@ -451,7 +451,8 @@ static void idxd_cmd_exec(struct idxd_device *idxd, int cmd_code, u32 operand, > > if (idxd_device_is_halted(idxd)) { > dev_warn(&idxd->pdev->dev, "Device is HALTED!\n"); > - *status = IDXD_CMDSTS_HW_ERR; > + if (status) > + *status = IDXD_CMDSTS_HW_ERR; > return; > } >