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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 97CEEC43219 for ; Sat, 6 Feb 2021 02:47:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 53A6964FEF for ; Sat, 6 Feb 2021 02:47:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229774AbhBFCb5 (ORCPT ); Fri, 5 Feb 2021 21:31:57 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37198 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229541AbhBFCa6 (ORCPT ); Fri, 5 Feb 2021 21:30:58 -0500 Received: from antares.kleine-koenig.org (antares.kleine-koenig.org [IPv6:2a01:4f8:c0c:3a97::2]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EEDC6C08EC87 for ; Fri, 5 Feb 2021 14:29:40 -0800 (PST) Received: by antares.kleine-koenig.org (Postfix, from userid 1000) id 745DAAEDEF9; Fri, 5 Feb 2021 23:28:58 +0100 (CET) From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= To: Dan Williams , Vishal Verma , Dave Jiang , Andrew Morton Cc: linux-nvdimm@lists.01.org, linux-kernel@vger.kernel.org, Greg Kroah-Hartman Subject: [PATCH v2 1/5] dax-device: Prevent registering drivers without probe callback Date: Fri, 5 Feb 2021 23:28:38 +0100 Message-Id: <20210205222842.34896-2-uwe@kleine-koenig.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210205222842.34896-1-uwe@kleine-koenig.org> References: <20210205222842.34896-1-uwe@kleine-koenig.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The bus probe function dax_bus_probe() calls the probe callback without checking it to be non-NULL. Prevent a NULL pointer exception if a driver without a probe function is registered by refusing to register this driver. Signed-off-by: Uwe Kleine-König --- drivers/dax/bus.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c index 737b207c9e30..72fc4b9b9ae6 100644 --- a/drivers/dax/bus.c +++ b/drivers/dax/bus.c @@ -1392,6 +1392,13 @@ int __dax_driver_register(struct dax_device_driver *dax_drv, struct device_driver *drv = &dax_drv->drv; int rc = 0; + /* + * dax_bus_probe() calls dax_drv->probe() unconditionally. + * So better be safe than sorry and ensure it is provided. + */ + if (!dax_drv->probe) + return -EINVAL; + INIT_LIST_HEAD(&dax_drv->ids); drv->owner = module; drv->name = mod_name; -- 2.29.2