From patchwork Thu May 20 09:22:37 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 444113 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=-19.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_RED, 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 207D1C43462 for ; Thu, 20 May 2021 11:00:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E2D59611AB for ; Thu, 20 May 2021 10:59:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238696AbhETLBS (ORCPT ); Thu, 20 May 2021 07:01:18 -0400 Received: from mail.kernel.org ([198.145.29.99]:56262 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239357AbhETK7G (ORCPT ); Thu, 20 May 2021 06:59:06 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id C2D2561D01; Thu, 20 May 2021 10:02:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1621504974; bh=/ZW8JwvHwnl77jWCkthAo3Vaac0GolRsZMMhyixU/f4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ziGdYPqUe/eBrObgGZ3T7B0PT388nwa+605icYvqqj1k/gAT7OGYFHzFAxPBqjOZg GDEHaieCr1neNOvhIgcMKtkZzAK+xqvRi3iEyhVOU2vPcbwnuhtiYXyu6V0fyQXayq JRptOxKF8UqJUlpZku3AEFuAD6Qa1W8n1vQY0yD0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dan Carpenter , Stefani Seibold , Andrew Morton , Linus Torvalds , Sasha Levin Subject: [PATCH 4.9 165/240] kfifo: fix ternary sign extension bugs Date: Thu, 20 May 2021 11:22:37 +0200 Message-Id: <20210520092114.188530857@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210520092108.587553970@linuxfoundation.org> References: <20210520092108.587553970@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Dan Carpenter [ Upstream commit 926ee00ea24320052b46745ef4b00d91c05bd03d ] The intent with this code was to return negative error codes but instead it returns positives. The problem is how type promotion works with ternary operations. These functions return long, "ret" is an int and "copied" is a u32. The negative error code is first cast to u32 so it becomes a high positive and then cast to long where it's still a positive. We could fix this by declaring "ret" as a ssize_t but let's just get rid of the ternaries instead. Link: https://lkml.kernel.org/r/YIE+/cK1tBzSuQPU@mwanda Fixes: 5bf2b19320ec ("kfifo: add example files to the kernel sample directory") Signed-off-by: Dan Carpenter Cc: Stefani Seibold Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- samples/kfifo/bytestream-example.c | 8 ++++++-- samples/kfifo/inttype-example.c | 8 ++++++-- samples/kfifo/record-example.c | 8 ++++++-- 3 files changed, 18 insertions(+), 6 deletions(-) diff --git a/samples/kfifo/bytestream-example.c b/samples/kfifo/bytestream-example.c index 2fca916d9edf..a7f5ee8b6edc 100644 --- a/samples/kfifo/bytestream-example.c +++ b/samples/kfifo/bytestream-example.c @@ -124,8 +124,10 @@ static ssize_t fifo_write(struct file *file, const char __user *buf, ret = kfifo_from_user(&test, buf, count, &copied); mutex_unlock(&write_lock); + if (ret) + return ret; - return ret ? ret : copied; + return copied; } static ssize_t fifo_read(struct file *file, char __user *buf, @@ -140,8 +142,10 @@ static ssize_t fifo_read(struct file *file, char __user *buf, ret = kfifo_to_user(&test, buf, count, &copied); mutex_unlock(&read_lock); + if (ret) + return ret; - return ret ? ret : copied; + return copied; } static const struct file_operations fifo_fops = { diff --git a/samples/kfifo/inttype-example.c b/samples/kfifo/inttype-example.c index 8dc3c2e7105a..a326a37e9163 100644 --- a/samples/kfifo/inttype-example.c +++ b/samples/kfifo/inttype-example.c @@ -117,8 +117,10 @@ static ssize_t fifo_write(struct file *file, const char __user *buf, ret = kfifo_from_user(&test, buf, count, &copied); mutex_unlock(&write_lock); + if (ret) + return ret; - return ret ? ret : copied; + return copied; } static ssize_t fifo_read(struct file *file, char __user *buf, @@ -133,8 +135,10 @@ static ssize_t fifo_read(struct file *file, char __user *buf, ret = kfifo_to_user(&test, buf, count, &copied); mutex_unlock(&read_lock); + if (ret) + return ret; - return ret ? ret : copied; + return copied; } static const struct file_operations fifo_fops = { diff --git a/samples/kfifo/record-example.c b/samples/kfifo/record-example.c index 2d7529eeb294..deb87a2e4e6b 100644 --- a/samples/kfifo/record-example.c +++ b/samples/kfifo/record-example.c @@ -131,8 +131,10 @@ static ssize_t fifo_write(struct file *file, const char __user *buf, ret = kfifo_from_user(&test, buf, count, &copied); mutex_unlock(&write_lock); + if (ret) + return ret; - return ret ? ret : copied; + return copied; } static ssize_t fifo_read(struct file *file, char __user *buf, @@ -147,8 +149,10 @@ static ssize_t fifo_read(struct file *file, char __user *buf, ret = kfifo_to_user(&test, buf, count, &copied); mutex_unlock(&read_lock); + if (ret) + return ret; - return ret ? ret : copied; + return copied; } static const struct file_operations fifo_fops = {