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=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 56663C33CAF for ; Thu, 16 Jan 2020 17:57:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 242A82073A for ; Thu, 16 Jan 2020 17:57:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579197431; bh=wktD1BteLyPPyytIdN3IcJavNeMlILjGaeCO9Oss1nM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=BLSHvB16yQ3WryfyXFRfNtMvyrHDARjVIOhHjGZ6KInEv/CpbLvXQEkEOTU/Uo31l hm3cmBDAk19qSv4yGdwC2blwUsjGUymGsNXZznRgLRoD5yF0Na1zy/WmBAVuSkfAMm Ums3ec5K0NDJlA0pD9eBbl8nuuXwAr203ZEjto/4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2394566AbgAPR5J (ORCPT ); Thu, 16 Jan 2020 12:57:09 -0500 Received: from mail.kernel.org ([198.145.29.99]:33948 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2393971AbgAPRnl (ORCPT ); Thu, 16 Jan 2020 12:43:41 -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 5394424748; Thu, 16 Jan 2020 17:43:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579196621; bh=wktD1BteLyPPyytIdN3IcJavNeMlILjGaeCO9Oss1nM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=p/iF/GoXI6Hk2YslHdzWWQCB+52mQ+KzqaTDfiy30km0LAFuqhMImRLlKt0Pf+FzZ NHYV4Z4SywYffFCmHOLKBMAl/8L6fzNz+9eba96UehRNAgNaoH2vvbTZU2hN8z1UB9 H4/zBZcTQfhiAPNAcxcQ4NjJtrnNOWHJ/A7D+J+g= 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 4.4 037/174] rtc: ds1672: fix unintended sign extension Date: Thu, 16 Jan 2020 12:40:34 -0500 Message-Id: <20200116174251.24326-37-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200116174251.24326-1-sashal@kernel.org> References: <20200116174251.24326-1-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 92b1cbf2c4a7..2bea733b1589 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); -- 2.20.1