From patchwork Tue Jan 28 14:04:18 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 232702 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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=unavailable 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 91E18C2D0DB for ; Tue, 28 Jan 2020 14:10:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 60CAA246A3 for ; Tue, 28 Jan 2020 14:10:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580220617; bh=jh53Q/Ozkk8U/82aeS6OkO2XtSpp62JCOjza6w+v6FY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=k6vyhmcnIhun9zxvGSDu0yDqBfEKvv25Qup1/fqhh3TPeJKOFc0IdmZEPnFMcaVih s2NPbNAw24zef8WIrTzMwITeZ7qxK3MrKK2f8G3fOJYHjXefu7RVbQzIhuBp8VecgZ t6iqM9ZT2z0/UDplOU4f3iRnhfYrEKy199d3kp9Q= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729130AbgA1OKN (ORCPT ); Tue, 28 Jan 2020 09:10:13 -0500 Received: from mail.kernel.org ([198.145.29.99]:58872 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729126AbgA1OKM (ORCPT ); Tue, 28 Jan 2020 09:10:12 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5C04324693; Tue, 28 Jan 2020 14:10:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580220611; bh=jh53Q/Ozkk8U/82aeS6OkO2XtSpp62JCOjza6w+v6FY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Q9NPs1XWNcWAwXTMILLGGxZQMamJKYmEqsxvCiRBGPnQLDY1VtbpLjcTJP8ejgg8N cpAB1SWUogKkee+aC858gsMXLStbYSlrhwfbQ5hbGBPHc7SI++b9lGAcFzSN/tcf0l A9kbMbsrVzADb0vscOZx8oFlcmj341c9V9LVtQeQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Colin Ian King , Alexandre Belloni , Sasha Levin Subject: [PATCH 4.4 039/183] rtc: ds1672: fix unintended sign extension Date: Tue, 28 Jan 2020 15:04:18 +0100 Message-Id: <20200128135833.915100317@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200128135829.486060649@linuxfoundation.org> References: <20200128135829.486060649@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Colin Ian King [ Upstream commit f0c04c276739ed8acbb41b4868e942a55b128dca ] Shifting a u8 by 24 will cause the value to be promoted to an integer. If the top bit of the u8 is set then the following conversion to an unsigned long will sign extend the value causing the upper 32 bits to be set in the result. Fix this by casting the u8 value to an unsigned long before the shift. Detected by CoverityScan, CID#138801 ("Unintended sign extension") Fixes: edf1aaa31fc5 ("[PATCH] RTC subsystem: DS1672 driver") Signed-off-by: Colin Ian King Signed-off-by: Alexandre Belloni Signed-off-by: Sasha Levin --- drivers/rtc/rtc-ds1672.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/rtc/rtc-ds1672.c b/drivers/rtc/rtc-ds1672.c index 92b1cbf2c4a76..2bea733b15893 100644 --- a/drivers/rtc/rtc-ds1672.c +++ b/drivers/rtc/rtc-ds1672.c @@ -60,7 +60,8 @@ static int ds1672_get_datetime(struct i2c_client *client, struct rtc_time *tm) "%s: raw read data - counters=%02x,%02x,%02x,%02x\n", __func__, buf[0], buf[1], buf[2], buf[3]); - time = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0]; + time = ((unsigned long)buf[3] << 24) | (buf[2] << 16) | + (buf[1] << 8) | buf[0]; rtc_time_to_tm(time, tm);