From patchwork Tue Dec 5 17:46:28 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Gustavo A. R. Silva" X-Patchwork-Id: 10095073 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 7939560327 for ; Wed, 6 Dec 2017 08:39:04 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6AC3B29C04 for ; Wed, 6 Dec 2017 08:39:04 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 5FA0929C10; Wed, 6 Dec 2017 08:39:04 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id D6C2C29C04 for ; Wed, 6 Dec 2017 08:39:03 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 67E686E6B0; Wed, 6 Dec 2017 08:38:50 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from gateway30.websitewelcome.com (gateway30.websitewelcome.com [192.185.193.11]) by gabe.freedesktop.org (Postfix) with ESMTPS id 601E76E5E4 for ; Tue, 5 Dec 2017 17:46:32 +0000 (UTC) Received: from cm16.websitewelcome.com (cm16.websitewelcome.com [100.42.49.19]) by gateway30.websitewelcome.com (Postfix) with ESMTP id 51D2C1545E for ; Tue, 5 Dec 2017 11:46:30 -0600 (CST) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id MHIceCyx0ODN4MHIceHwey; Tue, 05 Dec 2017 11:46:30 -0600 Received: from [189.155.98.198] (port=44308 helo=embeddedor) by gator4166.hostgator.com with esmtpa (Exim 4.89) (envelope-from ) id 1eMHIb-002k66-Mu; Tue, 05 Dec 2017 11:46:29 -0600 Date: Tue, 5 Dec 2017 11:46:28 -0600 From: "Gustavo A. R. Silva" To: Daniel Vetter , Jani Nikula , Gustavo Padovan , Sean Paul , David Airlie Subject: [PATCH] drm/fb-helper: Fix potential NULL pointer dereference Message-ID: <20171205174628.GA31189@embeddedor.com> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.5.24 (2015-08-30) X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - gator4166.hostgator.com X-AntiAbuse: Original Domain - lists.freedesktop.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - embeddedor.com X-BWhitelist: no X-Source-IP: 189.155.98.198 X-Source-L: No X-Exim-ID: 1eMHIb-002k66-Mu X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [189.155.98.198]:44308 X-Source-Auth: garsilva@embeddedor.com X-Email-Count: 11 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes X-Mailman-Approved-At: Wed, 06 Dec 2017 08:38:48 +0000 Cc: "Gustavo A. R. Silva" , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Virus-Scanned: ClamAV using ClamSMTP fb_helper is being dereferenced before it is null checked, hence there is a potential null pointer dereference. Fix this by moving the pointer dereference after fb_helper has been null checked. This issue was detected with the help of Coccinelle. Fixes: c777990fb45b ("drm/fb-helper: Handle function NULL argument") Signed-off-by: Gustavo A. R. Silva --- drivers/gpu/drm/drm_fb_helper.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c index 6654f2f..04a3a5c 100644 --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -178,7 +178,7 @@ EXPORT_SYMBOL(drm_fb_helper_add_one_connector); */ int drm_fb_helper_single_add_all_connectors(struct drm_fb_helper *fb_helper) { - struct drm_device *dev = fb_helper->dev; + struct drm_device *dev; struct drm_connector *connector; struct drm_connector_list_iter conn_iter; int i, ret = 0; @@ -186,6 +186,8 @@ int drm_fb_helper_single_add_all_connectors(struct drm_fb_helper *fb_helper) if (!drm_fbdev_emulation || !fb_helper) return 0; + dev = fb_helper->dev; + mutex_lock(&fb_helper->lock); drm_connector_list_iter_begin(dev, &conn_iter); drm_for_each_connector_iter(connector, &conn_iter) {