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=-12.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 16AE7C56202 for ; Fri, 13 Nov 2020 12:37:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D168E2224B for ; Fri, 13 Nov 2020 12:37:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726465AbgKMMhy (ORCPT ); Fri, 13 Nov 2020 07:37:54 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:54258 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726160AbgKMMhw (ORCPT ); Fri, 13 Nov 2020 07:37:52 -0500 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 1kdYKn-0000Dr-Kq; Fri, 13 Nov 2020 12:37:45 +0000 From: Colin King To: Anitha Chrisanthus , Edmund Dea , David Airlie , Daniel Vetter , Sam Ravnborg , dri-devel@lists.freedesktop.org Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH][next] drm/kmb: fix potential integer overflow on multiplication Date: Fri, 13 Nov 2020 12:37:45 +0000 Message-Id: <20201113123745.36799-1-colin.king@canonical.com> X-Mailer: git-send-email 2.28.0 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Colin Ian King There is a potential integer overflow when multiplying various sized integers that are cast to u32 integers using u32 multiplication and then assigning the result to a u64. Fix this by casting MIPI_TX_BPP to a u64 to force the multiplication to use u64 math and hence avoid any potential overflows. Addresses-Coverity: ("Unintentional integer overflow") Fixes: 98521f4d4b4c ("drm/kmb: Mipi DSI part of the display driver") Signed-off-by: Colin Ian King --- drivers/gpu/drm/kmb/kmb_dsi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/kmb/kmb_dsi.c b/drivers/gpu/drm/kmb/kmb_dsi.c index 4b5d82af84b3..6c3081356bd9 100644 --- a/drivers/gpu/drm/kmb/kmb_dsi.c +++ b/drivers/gpu/drm/kmb/kmb_dsi.c @@ -1369,7 +1369,7 @@ int kmb_dsi_mode_set(struct kmb_dsi *kmb_dsi, struct drm_display_mode *mode, */ data_rate = ((((u32)mode->crtc_vtotal * (u32)mode->crtc_htotal) * (u32)(drm_mode_vrefresh(mode)) * - MIPI_TX_BPP) / mipi_tx_init_cfg.active_lanes) / 1000000; + (u64)MIPI_TX_BPP) / mipi_tx_init_cfg.active_lanes) / 1000000; dev_dbg(kmb_dsi->dev, "data_rate=%u active_lanes=%d\n", (u32)data_rate, mipi_tx_init_cfg.active_lanes); -- 2.28.0