From patchwork Mon Dec 7 15:09:37 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Colin King X-Patchwork-Id: 11956183 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 8869CC4361B for ; Mon, 7 Dec 2020 15:09:46 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 26A812370D for ; Mon, 7 Dec 2020 15:09:46 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 26A812370D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=canonical.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 82DB189A4F; Mon, 7 Dec 2020 15:09:45 +0000 (UTC) Received: from youngberry.canonical.com (youngberry.canonical.com [91.189.89.112]) by gabe.freedesktop.org (Postfix) with ESMTPS id BB20A89A4F for ; Mon, 7 Dec 2020 15:09:43 +0000 (UTC) Received: from 1.general.cking.uk.vpn ([10.172.193.212] helo=localhost) by youngberry.canonical.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1kmI8v-0006O4-Im; Mon, 07 Dec 2020 15:09:37 +0000 From: Colin King To: Chun-Kuang Hu , Philipp Zabel , Chunfeng Yun , Kishon Vijay Abraham I , Vinod Koul , Matthias Brugger , CK Hu , chunhui dai , dri-devel@lists.freedesktop.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org Subject: [PATCH][next] drm/mediatek: avoid dereferencing a null hdmi_phy on an error message Date: Mon, 7 Dec 2020 15:09:37 +0000 Message-Id: <20201207150937.170435-1-colin.king@canonical.com> X-Mailer: git-send-email 2.29.2 MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" From: Colin Ian King Currently there is a null pointer check for hdmi_phy that implies it may be null, however a dev_err messages dereferences this potential null pointer. Avoid a null pointer dereference by only emitting the dev_err message if hdmi_phy is non-null. It is a moot point if the error message needs to be printed at all, but since this is a relatively new piece of code it may be useful to keep the message in for the moment in case there are unforseen errors that need to be reported. Addresses-Coverity: ("Dereference after null check") Fixes: be28b6507c46 ("drm/mediatek: separate hdmi phy to different file") Signed-off-by: Colin Ian King --- drivers/phy/mediatek/phy-mtk-hdmi.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/phy/mediatek/phy-mtk-hdmi.c b/drivers/phy/mediatek/phy-mtk-hdmi.c index c5c61f5a9ea0..5184054783c7 100644 --- a/drivers/phy/mediatek/phy-mtk-hdmi.c +++ b/drivers/phy/mediatek/phy-mtk-hdmi.c @@ -84,8 +84,9 @@ mtk_hdmi_phy_dev_get_ops(const struct mtk_hdmi_phy *hdmi_phy) hdmi_phy->conf->hdmi_phy_disable_tmds) return &mtk_hdmi_phy_dev_ops; - dev_err(hdmi_phy->dev, "Failed to get dev ops of phy\n"); - return NULL; + if (hdmi_phy) + dev_err(hdmi_phy->dev, "Failed to get dev ops of phy\n"); + return NULL; } static void mtk_hdmi_phy_clk_get_data(struct mtk_hdmi_phy *hdmi_phy,