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=-9.8 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=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 64953C2D0DB for ; Tue, 28 Jan 2020 14:17:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3961D24688 for ; Tue, 28 Jan 2020 14:17:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580221034; bh=yTxA6aDFcdfjGIzf+6Js8e99cEdZLEXqW9hUaiwDaNM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=cfMo7OcdOm/I+eRVbTYXDSj2tfSS3E16IkCOlP9wG2jiPq7Wi4j6Cngk0KLlaOcgq eunVqWFtkX2cEoatfTMnBfIJBS1HHuDLEO0QNz5gEnCk1mNm9p1O24dfKTC6WTzZ0V uKdjEavikEmWvvxKYNH7NijCnGr1lcNnxYv1fAXE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730470AbgA1ORN (ORCPT ); Tue, 28 Jan 2020 09:17:13 -0500 Received: from mail.kernel.org ([198.145.29.99]:40826 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729986AbgA1ORK (ORCPT ); Tue, 28 Jan 2020 09:17:10 -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 7DFF62071E; Tue, 28 Jan 2020 14:17:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580221030; bh=yTxA6aDFcdfjGIzf+6Js8e99cEdZLEXqW9hUaiwDaNM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=aWwX8EmXoPdR6CcjBciWRWI3lGHN1LZOyT3iWpldR7n+1rMwDO7yhNOfV0QNrLx41 0KZcbCm21xWz8dfb8t6meNrE/cPEAubjLXdTua2YURUzvIKuIdeVMRuiJtrI6K8vrl KCgs2bld+PdyRY5X0W0ibq08aK6YOk+7NawwIVKM= 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 4.9 059/271] rtc: ds1672: fix unintended sign extension Date: Tue, 28 Jan 2020 15:03:28 +0100 Message-Id: <20200128135857.028216999@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200128135852.449088278@linuxfoundation.org> References: <20200128135852.449088278@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 5c18ac7394c42..c911f2db0af5e 100644 --- a/drivers/rtc/rtc-ds1672.c +++ b/drivers/rtc/rtc-ds1672.c @@ -58,7 +58,8 @@ 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); -- 2.20.1