Received: by 2002:a05:6a10:f3d0:0:0:0:0 with SMTP id a16csp2836066pxv; Mon, 12 Jul 2021 03:08:30 -0700 (PDT) X-Google-Smtp-Source: ABdhPJyRzFuq9RgwOJ601Y6mHbczc+CU5QIQmZPlU3zIqiZ9OYVELs0QwRSZC6wcUPLyvd36RalP X-Received: by 2002:a5d:8c9a:: with SMTP id g26mr30967785ion.121.1626084510168; Mon, 12 Jul 2021 03:08:30 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1626084510; cv=none; d=google.com; s=arc-20160816; b=e0hUigTqSfYXJL8gsfnWF/SnpdkV8OCX9yLPQQAbTpK/aAskHCTHa3RxXBWHezaZ2I lAUTSz8jAWX9Od2fo5Pya7n1wRUedSIPicoWNA//cj4jGqauHx6g2hSdtNqMdjZDoHRr hTseVVVk8MoG/zf6uvM5jbCPQ0Vt1iFDVKp6MjFfPuRwxQlYpokxZ2/YaFTwyX3oYPVH WV/JOssKPXBug06txWBpu0okCynIFm7n0E9YwzL8IdRnZj+x4fNXfJXQX/mn3ulxmd5p U0cKCi1kTA0/2KjJrmqkpCf3S11a/MY6gAWoe0KNKDDbnZJVovQfJ9vdyan58fmdmdkP tRuw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :user-agent:references:in-reply-to:message-id:date:subject:cc:to :from:dkim-signature; bh=K+FF+goQR298AYrRt2zKYCVcaDEmJBGvnESEOU3UGXU=; b=WYmLx9NQ5CByUhxWXliJo/v+v0XFW1cRXZETnP0lVbYJXcqyBue24nGsdsYbNMydJb Gasd9PyDcB4BbvvePxzZt+mqpi2Scqpgx8uzy5u+M2+7rqUafWjC+kpQph++6mAn61IJ EPjCKLaI7n1dCcAPpitcHhmeD7AK2Askf1XsAcIbAkrFq21qCJWPG9jRrmYaLYGoIQsG JSaOVaEFymM1vLadOesPGbz2jm74kCWdCAodnZcS8qabkvEGJGZOOlfDQhodUXlmlYR/ TgJwCJYc+h+8RmpHbgysAgY76i2sl1KAbYttzUmxZ/0rNSAFkAmZixW6iBB0ulRHBRB7 XbcA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@linuxfoundation.org header.s=korg header.b=Bigi8iOc; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linuxfoundation.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id d21si440137jam.9.2021.07.12.03.08.18; Mon, 12 Jul 2021 03:08:30 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@linuxfoundation.org header.s=korg header.b=Bigi8iOc; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linuxfoundation.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344703AbhGLHrt (ORCPT + 99 others); Mon, 12 Jul 2021 03:47:49 -0400 Received: from mail.kernel.org ([198.145.29.99]:46652 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241035AbhGLHNq (ORCPT ); Mon, 12 Jul 2021 03:13:46 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id E77C061166; Mon, 12 Jul 2021 07:10:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626073849; bh=wyMWFanJk4V0p8E7UCLTYW9/FtAYpGWdH2tr4Hp7hEM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Bigi8iOc55Ob3VH81fAVqcvl920xGHGP2nIj97yF0ZmfiJM2aYApeAcMQoTgX8GhQ v+D3sFCk/RCvzlaR8jt9kU0t0BQiVtCaDvp+ZLto0bjszHt4yMu835duCECuXbVl0m ag6v2vaQIXtHv0bvYKcGER1BfNrefs0qy+na0b/g= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Colin Ian King , Guenter Roeck , Heiko Stuebner , Sasha Levin Subject: [PATCH 5.12 379/700] drm/rockchip: cdn-dp: fix sign extension on an int multiply for a u64 result Date: Mon, 12 Jul 2021 08:07:42 +0200 Message-Id: <20210712061016.649207788@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210712060924.797321836@linuxfoundation.org> References: <20210712060924.797321836@linuxfoundation.org> User-Agent: quilt/0.66 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 [ Upstream commit ce0cb93a5adb283f577cd4661f511047b5e39028 ] The variable bit_per_pix is a u8 and is promoted in the multiplication to an int type and then sign extended to a u64. If the result of the int multiplication is greater than 0x7fffffff then the upper 32 bits will be set to 1 as a result of the sign extension. Avoid this by casting tu_size_reg to u64 to avoid sign extension and also a potential overflow. Fixes: 1a0f7ed3abe2 ("drm/rockchip: cdn-dp: add cdn DP support for rk3399") Signed-off-by: Colin Ian King Reviewed-by: Guenter Roeck Signed-off-by: Heiko Stuebner Link: https://patchwork.freedesktop.org/patch/msgid/20200915162049.36434-1-colin.king@canonical.com Signed-off-by: Sasha Levin --- drivers/gpu/drm/rockchip/cdn-dp-reg.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/rockchip/cdn-dp-reg.c b/drivers/gpu/drm/rockchip/cdn-dp-reg.c index 9d2163ef4d6e..33fb4d05c506 100644 --- a/drivers/gpu/drm/rockchip/cdn-dp-reg.c +++ b/drivers/gpu/drm/rockchip/cdn-dp-reg.c @@ -658,7 +658,7 @@ int cdn_dp_config_video(struct cdn_dp_device *dp) */ do { tu_size_reg += 2; - symbol = tu_size_reg * mode->clock * bit_per_pix; + symbol = (u64)tu_size_reg * mode->clock * bit_per_pix; do_div(symbol, dp->max_lanes * link_rate * 8); rem = do_div(symbol, 1000); if (tu_size_reg > 64) { -- 2.30.2