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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT 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 1B10EC4332E for ; Fri, 20 Mar 2020 16:30:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E818F2080C for ; Fri, 20 Mar 2020 16:30:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727561AbgCTQaH (ORCPT ); Fri, 20 Mar 2020 12:30:07 -0400 Received: from mga05.intel.com ([192.55.52.43]:35562 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727122AbgCTQaG (ORCPT ); Fri, 20 Mar 2020 12:30:06 -0400 IronPort-SDR: aQQ99C2CSyrbpVe15F+diDr7YEO2utKZ1NVc0fm9ICumWdnE9aguxgRIobrCDMacXMKHwAfgVL JvYRkvSgDcFQ== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga006.jf.intel.com ([10.7.209.51]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Mar 2020 09:30:05 -0700 IronPort-SDR: bHWPirFfuFYtgMU59MmbNvzP61dZoKTzksjLxclgAiV7iNaeKV4yNZ16ocT2TZz07y/C009pf4 p/Jot+7gEqLg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.72,285,1580803200"; d="scan'208";a="248930916" Received: from manallet-mobl.amr.corp.intel.com (HELO pbossart-mobl3.amr.corp.intel.com) ([10.255.34.12]) by orsmga006.jf.intel.com with ESMTP; 20 Mar 2020 09:30:02 -0700 From: Pierre-Louis Bossart To: alsa-devel@alsa-project.org Cc: linux-kernel@vger.kernel.org, tiwai@suse.de, broonie@kernel.org, vkoul@kernel.org, gregkh@linuxfoundation.org, jank@cadence.com, srinivas.kandagatla@linaro.org, slawomir.blauciak@intel.com, Bard liao , Rander Wang , Ranjani Sridharan , Hui Wang , Pierre-Louis Bossart , Sanyog Kale Subject: [PATCH 2/5] soundwire: bus_type: protect cases where no driver name is provided Date: Fri, 20 Mar 2020 11:29:44 -0500 Message-Id: <20200320162947.17663-3-pierre-louis.bossart@linux.intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200320162947.17663-1-pierre-louis.bossart@linux.intel.com> References: <20200320162947.17663-1-pierre-louis.bossart@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When the implementation only creates a sdw_master_device and does not provide a master_name, we have a risk of kernel oopses with dereferences of a NULL pointer. Protect with explicit tests. Signed-off-by: Pierre-Louis Bossart --- drivers/soundwire/bus_type.c | 22 +++++++++++++--------- 1 file changed, 13 insertions(+), 9 deletions(-) diff --git a/drivers/soundwire/bus_type.c b/drivers/soundwire/bus_type.c index 09a25075e770..c01d74c709d5 100644 --- a/drivers/soundwire/bus_type.c +++ b/drivers/soundwire/bus_type.c @@ -48,12 +48,14 @@ static int sdw_bus_match(struct device *dev, struct device_driver *ddrv) md = dev_to_sdw_master_device(dev); mdrv = drv_to_sdw_master_driver(ddrv); - /* - * we don't have any hardware information so - * match with a hopefully unique string - */ - ret = !strncmp(md->master_name, mdrv->driver.name, - strlen(md->master_name)); + if (md->master_name) { + /* + * we don't have any hardware information so + * match with a hopefully unique string + */ + ret = !strncmp(md->master_name, mdrv->driver.name, + strlen(md->master_name)); + } } return ret; } @@ -71,9 +73,11 @@ static int sdw_master_modalias(const struct sdw_master_device *md, char *buf, size_t size) { /* modalias is sdw: since we don't have any hardware info */ - - return snprintf(buf, size, "sdw:%s\n", - md->master_name); + if (md->master_name) + return snprintf(buf, size, "sdw:%s\n", + md->master_name); + else + return snprintf(buf, size, "sdw:no_master_driver\n"); } static int sdw_uevent(struct device *dev, struct kobj_uevent_env *env) -- 2.20.1