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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 34A52C33CAF for ; Thu, 16 Jan 2020 17:37:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 01A4C246B7 for ; Thu, 16 Jan 2020 17:37:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579196229; bh=t2GXjzwBgoeqYAw8napByv5NY1waa24NneZgdpaJBzE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=JNdUvpmHUtthkvu9qYpDLDvXVIwXfx34yu/5dDhHLPER0AC4QKW9kso3mzbI54iXt nJUX++ouJIhAxO9hRNd+Qt2EhXbwU/p0Ac3pXKLheZWJ2pZW/NOiIyRODC0g/21aic P2sdoBQkuXwbo3ncZp1I/Mot4s0Dd1JbA7tKXpIY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2405304AbgAPRhI (ORCPT ); Thu, 16 Jan 2020 12:37:08 -0500 Received: from mail.kernel.org ([198.145.29.99]:52088 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2405281AbgAPRhD (ORCPT ); Thu, 16 Jan 2020 12:37:03 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 4D1692468C; Thu, 16 Jan 2020 17:37:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579196223; bh=t2GXjzwBgoeqYAw8napByv5NY1waa24NneZgdpaJBzE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OzreNqh0WIHZ4tnqr/NcFLCg5wH4QFHD0OX6Dlleslksj/7Riij1KmB7PjSxNFhqn X7T3Z6HqSY7P7/efyiO7dSa3Imfcr9E6acno8HRMs6p1CeceeelEv0UUKxfmnPUhOS +/pslDHirFrz29ZGG7/iVo4833KKeu+cNm0lflIk= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Colin Ian King , Alexandre Belloni , Sasha Levin , linux-rtc@vger.kernel.org Subject: [PATCH AUTOSEL 4.9 057/251] rtc: ds1672: fix unintended sign extension Date: Thu, 16 Jan 2020 12:33:26 -0500 Message-Id: <20200116173641.22137-17-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200116173641.22137-1-sashal@kernel.org> References: <20200116173641.22137-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore 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 5c18ac7394c4..c911f2db0af5 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