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 C9EF3C4360F for ; Wed, 3 Apr 2019 09:20:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9F8CD20830 for ; Wed, 3 Apr 2019 09:20:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726468AbfDCJUl (ORCPT ); Wed, 3 Apr 2019 05:20:41 -0400 Received: from mx08-00178001.pphosted.com ([91.207.212.93]:2788 "EHLO mx07-00178001.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725907AbfDCJUl (ORCPT ); Wed, 3 Apr 2019 05:20:41 -0400 Received: from pps.filterd (m0046660.ppops.net [127.0.0.1]) by mx08-00178001.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x3397F3d015828; Wed, 3 Apr 2019 11:20:30 +0200 Received: from beta.dmz-eu.st.com (beta.dmz-eu.st.com [164.129.1.35]) by mx08-00178001.pphosted.com with ESMTP id 2rmhar2tes-1 (version=TLSv1 cipher=ECDHE-RSA-AES256-SHA bits=256 verify=NOT); Wed, 03 Apr 2019 11:20:30 +0200 Received: from zeta.dmz-eu.st.com (zeta.dmz-eu.st.com [164.129.230.9]) by beta.dmz-eu.st.com (STMicroelectronics) with ESMTP id 0801931; Wed, 3 Apr 2019 09:20:30 +0000 (GMT) Received: from Webmail-eu.st.com (Safex1hubcas22.st.com [10.75.90.92]) by zeta.dmz-eu.st.com (STMicroelectronics) with ESMTP id DBC641863; Wed, 3 Apr 2019 09:20:29 +0000 (GMT) Received: from SAFEX1HUBCAS23.st.com (10.75.90.47) by Safex1hubcas22.st.com (10.75.90.92) with Microsoft SMTP Server (TLS) id 14.3.361.1; Wed, 3 Apr 2019 11:20:29 +0200 Received: from localhost (10.201.23.97) by webmail-ga.st.com (10.75.90.48) with Microsoft SMTP Server (TLS) id 14.3.435.0; Wed, 3 Apr 2019 11:20:29 +0200 From: =?UTF-8?q?Yannick=20Fertr=C3=A9?= To: Yannick Fertre , Philippe Cornu , Benjamin Gaignard , Vincent Abriou , David Airlie , Daniel Vetter , Maxime Coquelin , Alexandre Torgue , , , , Subject: [PATCH] drm/stm: ltdc: limit number of layer to avoid memory overflow Date: Wed, 3 Apr 2019 11:20:16 +0200 Message-ID: <1554283216-2700-1-git-send-email-yannick.fertre@st.com> X-Mailer: git-send-email 2.7.4 MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit X-Originating-IP: [10.201.23.97] X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-04-03_05:,, signatures=0 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org If the number of layer is greater than LTDC_MAX_LAYER, we can have memory overflow when reading plane_fpsi[]. Signed-off-by: Yannick Fertré --- drivers/gpu/drm/stm/ltdc.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c index 32fd6a3..05bd4b6 100644 --- a/drivers/gpu/drm/stm/ltdc.c +++ b/drivers/gpu/drm/stm/ltdc.c @@ -1021,10 +1021,13 @@ static int ltdc_get_caps(struct drm_device *ddev) struct ltdc_device *ldev = ddev->dev_private; u32 bus_width_log2, lcr, gc2r; - /* at least 1 layer must be managed */ + /* + * at least 1 layer must be managed & the number of layers + * must not exceed LTDC_MAX_LAYER + */ lcr = reg_read(ldev->regs, LTDC_LCR); - ldev->caps.nb_layers = max_t(int, lcr, 1); + ldev->caps.nb_layers = clamp((int)lcr, 1, LTDC_MAX_LAYER); /* set data bus width */ gc2r = reg_read(ldev->regs, LTDC_GC2R); -- 2.7.4