From nobody Fri May 8 05:17:35 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DC611C433F5 for ; Tue, 10 May 2022 14:59:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244969AbiEJPDm (ORCPT ); Tue, 10 May 2022 11:03:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39168 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345245AbiEJPDX (ORCPT ); Tue, 10 May 2022 11:03:23 -0400 Received: from mx07-00178001.pphosted.com (mx08-00178001.pphosted.com [91.207.212.93]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 757CC22906B for ; Tue, 10 May 2022 07:26:46 -0700 (PDT) Received: from pps.filterd (m0046661.ppops.net [127.0.0.1]) by mx07-00178001.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 24AA1Sdn011815; Tue, 10 May 2022 16:26:21 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=foss.st.com; h=from : to : cc : subject : date : message-id : mime-version : content-transfer-encoding : content-type; s=selector1; bh=2ANARSm+ciPJ+EjWxzvHYDRB4kCEaNE52zN2k7UHgmI=; b=cnAreZzybHx90XAf0OpH2JQdBBCyuOAxvBFJiz/p45vtOREgtV/yR42ihA+9J6VTrCqA 618UFwYEMvF4Ez5JUQMtfHEtmvQurvbYOoDZzy5ARYPvDgJceIW4IubgmN6Dh1W49xWw h0asDzAQouDf7OoofPM8wuJxqY0OmzbWdrtT8iNJNH8ZyeiQaPJnlTwGnuvArTKr0rEz g+rsUZRVf/zGhh3LMX06Nj4KKExpLvZWLlv3O8txWDsDcdBbFw2ds4UID+kxL14DsC76 Wx2/vCAcPSWYaO8qd4y960rfj5CvqPVcbAQGaDT3eLpZGOf0RX+BJZIoq+aCH3byyrMc gg== Received: from beta.dmz-eu.st.com (beta.dmz-eu.st.com [164.129.1.35]) by mx07-00178001.pphosted.com (PPS) with ESMTPS id 3fwfngjywv-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 10 May 2022 16:26:21 +0200 Received: from euls16034.sgp.st.com (euls16034.sgp.st.com [10.75.44.20]) by beta.dmz-eu.st.com (STMicroelectronics) with ESMTP id 5449610002A; Tue, 10 May 2022 16:26:17 +0200 (CEST) Received: from Webmail-eu.st.com (sfhdag2node2.st.com [10.75.127.5]) by euls16034.sgp.st.com (STMicroelectronics) with ESMTP id 408252291D0; Tue, 10 May 2022 16:26:17 +0200 (CEST) Received: from localhost (10.75.127.50) by SFHDAG2NODE2.st.com (10.75.127.5) with Microsoft SMTP Server (TLS) id 15.0.1497.26; Tue, 10 May 2022 16:26:16 +0200 From: Raphael Gallais-Pou To: Yannick Fertre , Philippe Cornu CC: David Airlie , Daniel Vetter , Maxime Coquelin , Alexandre Torgue , , , , , Raphael Gallais-Pou , kernel test robot , Dan Carpenter Subject: [PATCH] drm/stm: ltdc: fix unchecked dereferenced pointer Date: Tue, 10 May 2022 16:24:03 +0200 Message-ID: <20220510142403.835902-1-raphael.gallais-pou@foss.st.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.75.127.50] X-ClientProxiedBy: SFHDAG2NODE3.st.com (10.75.127.6) To SFHDAG2NODE2.st.com (10.75.127.5) X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.858,Hydra:6.0.486,FMLib:17.11.64.514 definitions=2022-05-10_03,2022-05-10_01,2022-02-23_01 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Pointer of struct *drm_crtc was dereferenced before checking it was non NULL. This could potentially create a kernel panic. Fixes: 79b44684a14e ("drm/stm: ltdc: add support for CRC hashing feature") Reported-by: kernel test robot Reported-by: Dan Carpenter Signed-off-by: Raphael Gallais-Pou --- drivers/gpu/drm/stm/ltdc.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c index 6bd45df8f5a7..9c0fadd58d2a 100644 --- a/drivers/gpu/drm/stm/ltdc.c +++ b/drivers/gpu/drm/stm/ltdc.c @@ -1120,7 +1120,7 @@ static void ltdc_crtc_disable_vblank(struct drm_crtc = *crtc) =20 static int ltdc_crtc_set_crc_source(struct drm_crtc *crtc, const char *sou= rce) { - struct ltdc_device *ldev =3D crtc_to_ltdc(crtc); + struct ltdc_device *ldev; int ret; =20 DRM_DEBUG_DRIVER("\n"); @@ -1128,6 +1128,8 @@ static int ltdc_crtc_set_crc_source(struct drm_crtc *= crtc, const char *source) if (!crtc) return -ENODEV; =20 + ldev =3D crtc_to_ltdc(crtc); + if (source && strcmp(source, "auto") =3D=3D 0) { ldev->crc_active =3D true; ret =3D regmap_set_bits(ldev->regmap, LTDC_GCR, GCR_CRCEN); --=20 2.25.1