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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 42B68C4161D for ; Tue, 20 Nov 2018 17:18:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 05C3D206BB for ; Tue, 20 Nov 2018 17:17:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 05C3D206BB Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=canonical.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730389AbeKUDsD (ORCPT ); Tue, 20 Nov 2018 22:48:03 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:34377 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727085AbeKUDsC (ORCPT ); Tue, 20 Nov 2018 22:48:02 -0500 Received: from 1.general.cking.uk.vpn ([10.172.193.212] helo=localhost) by youngberry.canonical.com with esmtpsa (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.76) (envelope-from ) id 1gP9ej-0006rb-Vs; Tue, 20 Nov 2018 17:17:46 +0000 From: Colin King To: Harry Wentland , Leo Li , Alex Deucher , =?UTF-8?q?Christian=20K=C3=B6nig?= , David Zhou , David Airlie , amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH][drm-next] drm/amd/display: fix dereference of pointer fs_params before it is null checked Date: Tue, 20 Nov 2018 17:17:45 +0000 Message-Id: <20181120171745.13812-1-colin.king@canonical.com> X-Mailer: git-send-email 2.19.1 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Colin Ian King Currently there are several instances of pointer fs_params being dereferenced before fs_params is being null checked. Fix this by only dereferencing fs_params after the null check. Detected by CoverityScan, CID#1475565 ("Dereference before null check") Fixes: e1e8a020c6b8 ("drm/amd/display: Add support for Freesync 2 HDR and Content to Display Mapping") Signed-off-by: Colin Ian King --- .../drm/amd/display/modules/color/color_gamma.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/amd/display/modules/color/color_gamma.c b/drivers/gpu/drm/amd/display/modules/color/color_gamma.c index 7480f072c375..bbecbaefb741 100644 --- a/drivers/gpu/drm/amd/display/modules/color/color_gamma.c +++ b/drivers/gpu/drm/amd/display/modules/color/color_gamma.c @@ -813,20 +813,26 @@ static bool build_freesync_hdr(struct pwl_float_data_ex *rgb_regamma, const struct hw_x_point *coord_x = coordinate_x; struct fixed31_32 scaledX = dc_fixpt_zero; struct fixed31_32 scaledX1 = dc_fixpt_zero; - struct fixed31_32 max_display = dc_fixpt_from_int(fs_params->max_display); - struct fixed31_32 min_display = dc_fixpt_from_fraction(fs_params->min_display, 10000); - struct fixed31_32 max_content = dc_fixpt_from_int(fs_params->max_content); - struct fixed31_32 min_content = dc_fixpt_from_fraction(fs_params->min_content, 10000); + struct fixed31_32 max_display; + struct fixed31_32 min_display; + struct fixed31_32 max_content; + struct fixed31_32 min_content; struct fixed31_32 clip = dc_fixpt_one; struct fixed31_32 output; bool use_eetf = false; bool is_clipped = false; - struct fixed31_32 sdr_white_level = dc_fixpt_from_int(fs_params->sdr_white_level); + struct fixed31_32 sdr_white_level; if (fs_params == NULL || fs_params->max_content == 0 || fs_params->max_display == 0) return false; + max_display = dc_fixpt_from_int(fs_params->max_display); + min_display = dc_fixpt_from_fraction(fs_params->min_display, 10000); + max_content = dc_fixpt_from_int(fs_params->max_content); + min_content = dc_fixpt_from_fraction(fs_params->min_content, 10000); + sdr_white_level = dc_fixpt_from_int(fs_params->sdr_white_level); + if (fs_params->min_display > 1000) // cap at 0.1 at the bottom min_display = dc_fixpt_from_fraction(1, 10); if (fs_params->max_display < 100) // cap at 100 at the top -- 2.19.1