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 43467C33CB3 for ; Thu, 16 Jan 2020 18:34:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 16D2B2073A for ; Thu, 16 Jan 2020 18:34:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579199671; bh=4KwJYEY4NLAQPKKbonyJb+ZFRqThbJv4RYUN1FP+KZk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=adlg5c7dj+AyIKJ4st+CyKQ7IWdoRgZksPbvVEOgO8hpcmyhqWovx71co7j1qOP7J qlEvAy6N7MsguRckil0TjbZpoQerNdGyR9ucrlgSRiarFtlAiHSFFTl3FPhJMZSHFs jgJobODeHWfoonZESm0Hr9ToIfxBg5VoTrGdn2AM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388461AbgAPSe2 (ORCPT ); Thu, 16 Jan 2020 13:34:28 -0500 Received: from mail.kernel.org ([198.145.29.99]:59456 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391788AbgAPRYh (ORCPT ); Thu, 16 Jan 2020 12:24:37 -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 3CB1A24692; Thu, 16 Jan 2020 17:24:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579195476; bh=4KwJYEY4NLAQPKKbonyJb+ZFRqThbJv4RYUN1FP+KZk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vMW+fLDkOYWCA3vxstjUZP5sVsEoDMuoqREuIoccfdAmx14z+VAzgQJDRDmJ2m6Cn YbidRyEZT5tvOWU6Djpew6nCABPDvK5BXI2Kx6YfEOO2g4d+AgyY9cBlELjwecUUVd ELUL+Fau4TeQYKkKbnQnRAYcAR4Giyzeq0WixJk0= 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 4.14 082/371] rtc: ds1672: fix unintended sign extension Date: Thu, 16 Jan 2020 12:19:14 -0500 Message-Id: <20200116172403.18149-25-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200116172403.18149-1-sashal@kernel.org> References: <20200116172403.18149-1-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 9caaccccaa57..b1ebca099b0d 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