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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 400DCC4338F for ; Thu, 29 Jul 2021 12:04:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 212CF60231 for ; Thu, 29 Jul 2021 12:04:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236878AbhG2MEP (ORCPT ); Thu, 29 Jul 2021 08:04:15 -0400 Received: from smtp03.smtpout.orange.fr ([80.12.242.125]:43871 "EHLO smtp.smtpout.orange.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234826AbhG2MEK (ORCPT ); Thu, 29 Jul 2021 08:04:10 -0400 Received: from localhost.localdomain ([86.243.172.93]) by mwinf5d05 with ME id b0432500421Fzsu03043Zp; Thu, 29 Jul 2021 14:04:06 +0200 X-ME-Helo: localhost.localdomain X-ME-Auth: Y2hyaXN0b3BoZS5qYWlsbGV0QHdhbmFkb28uZnI= X-ME-Date: Thu, 29 Jul 2021 14:04:06 +0200 X-ME-IP: 86.243.172.93 From: Christophe JAILLET To: dave.jiang@intel.com, vkoul@kernel.org, dan.j.williams@intel.com Cc: dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org, Christophe JAILLET Subject: [PATCH] dmaengine: idxd: Fix a possible NULL pointer dereference Date: Thu, 29 Jul 2021 14:04:01 +0200 Message-Id: <77f0dc4f3966591d1f0cffb614a94085f8895a85.1627560174.git.christophe.jaillet@wanadoo.fr> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org 'device_driver_attach()' dereferences its first argument (i.e. 'alt_drv') so it must not be NULL. Simplify the error handling logic about NULL 'alt_drv' in order to be more robust and future-proof. Fixes: 568b2126466f ("dmaengine: idxd: fix uninit var for alt_drv") Fixes: 6e7f3ee97bbe ("dmaengine: idxd: move dsa_drv support to compatible mode") Signed-off-by: Christophe JAILLET --- drivers/dma/idxd/compat.c | 15 ++++----------- 1 file changed, 4 insertions(+), 11 deletions(-) diff --git a/drivers/dma/idxd/compat.c b/drivers/dma/idxd/compat.c index d7616c240dcd..3df21615f888 100644 --- a/drivers/dma/idxd/compat.c +++ b/drivers/dma/idxd/compat.c @@ -45,23 +45,16 @@ static ssize_t bind_store(struct device_driver *drv, const char *buf, size_t cou idxd_dev = confdev_to_idxd_dev(dev); if (is_idxd_dev(idxd_dev)) { alt_drv = driver_find("idxd", bus); - if (!alt_drv) - return -ENODEV; } else if (is_idxd_wq_dev(idxd_dev)) { struct idxd_wq *wq = confdev_to_wq(dev); - if (is_idxd_wq_kernel(wq)) { + if (is_idxd_wq_kernel(wq)) alt_drv = driver_find("dmaengine", bus); - if (!alt_drv) - return -ENODEV; - } else if (is_idxd_wq_user(wq)) { + else if (is_idxd_wq_user(wq)) alt_drv = driver_find("user", bus); - if (!alt_drv) - return -ENODEV; - } else { - return -ENODEV; - } } + if (!alt_drv) + return -ENODEV; rc = device_driver_attach(alt_drv, dev); if (rc < 0) -- 2.30.2