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=-19.4 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, 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 CA01FC433B4 for ; Wed, 12 May 2021 17:06:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 92F9760232 for ; Wed, 12 May 2021 17:06:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345135AbhELRHH (ORCPT ); Wed, 12 May 2021 13:07:07 -0400 Received: from mail.kernel.org ([198.145.29.99]:46628 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244641AbhELQu5 (ORCPT ); Wed, 12 May 2021 12:50:57 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 35E6161C84; Wed, 12 May 2021 16:17:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1620836236; bh=42TrdJ6vRDRiwh71ldf9/z4htKYkP4JsmoC3QXfPeEU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xP4In9n2LJMERsxLy1/+kgdtV37ygV3v8mG4JSxf8HzY6O5ETCqTTtU4AkiKobG55 SAMXGo6CIpUZBy48lu+qkQf5qw14k456k36c/Upi3y+gCYxJkedWYjI+IX8vffdAPn 7Pe8N3RBRDUB+wZIkreGes+xID+sa7s/EJDaLADI= 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 5.12 665/677] kfifo: fix ternary sign extension bugs Date: Wed, 12 May 2021 16:51:51 +0200 Message-Id: <20210512144859.463085398@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210512144837.204217980@linuxfoundation.org> References: <20210512144837.204217980@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 c406f03ee551..5a90aa527877 100644 --- a/samples/kfifo/bytestream-example.c +++ b/samples/kfifo/bytestream-example.c @@ -122,8 +122,10 @@ 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, @@ -138,8 +140,10 @@ 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 proc_ops fifo_proc_ops = { diff --git a/samples/kfifo/inttype-example.c b/samples/kfifo/inttype-example.c index 78977fc4a23f..e5403d8c971a 100644 --- a/samples/kfifo/inttype-example.c +++ b/samples/kfifo/inttype-example.c @@ -115,8 +115,10 @@ 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, @@ -131,8 +133,10 @@ 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 proc_ops fifo_proc_ops = { diff --git a/samples/kfifo/record-example.c b/samples/kfifo/record-example.c index c507998a2617..f64f3d62d6c2 100644 --- a/samples/kfifo/record-example.c +++ b/samples/kfifo/record-example.c @@ -129,8 +129,10 @@ 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, @@ -145,8 +147,10 @@ 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 proc_ops fifo_proc_ops = { -- 2.30.2