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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 9C6FAC64E7C for ; Sun, 22 Nov 2020 06:17:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 51D512137B for ; Sun, 22 Nov 2020 06:17:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="YcGUnQou" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727367AbgKVGRU (ORCPT ); Sun, 22 Nov 2020 01:17:20 -0500 Received: from mail.kernel.org ([198.145.29.99]:55854 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726957AbgKVGRU (ORCPT ); Sun, 22 Nov 2020 01:17:20 -0500 Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 6A7E120885; Sun, 22 Nov 2020 06:17:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1606025839; bh=/2Crv0yoiGPOCLVKKOZFGvlgsyX0gwPsx26XT6y4Hic=; h=Date:From:To:Subject:In-Reply-To:From; b=YcGUnQouy7cmjuVazzFinG4TubZQzc6mgE9014ANI+Of0Wzyf2V1rIVgZM64BropQ emsoNSDV1Mc+8webiTxV/YzxwhXOs90vCz4xScg1y7HC11cWADZd7kZtf3OjSrmuiL umyGQwpqdqLc8Mhmvbkepf0mbOSh/gmVkTr/8zKY= Date: Sat, 21 Nov 2020 22:17:19 -0800 From: Andrew Morton To: akpm@linux-foundation.org, linux-mm@kvack.org, mm-commits@vger.kernel.org, torvalds@linux-foundation.org, viro@zeniv.linux.org.uk, yangyicong@hisilicon.com Subject: [patch 7/8] libfs: fix error cast of negative value in simple_attr_write() Message-ID: <20201122061719.7voMbHRfP%akpm@linux-foundation.org> In-Reply-To: <20201121221631.948ae4655e913a319d61700a@linux-foundation.org> User-Agent: s-nail v14.8.16 Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org From: Yicong Yang Subject: libfs: fix error cast of negative value in simple_attr_write() The attr->set() receive a value of u64, but simple_strtoll() is used for doing the conversion. It will lead to the error cast if user inputs a negative value. Use kstrtoull() instead of simple_strtoll() to convert a string got from the user to an unsigned value. The former will return '-EINVAL' if it gets a negetive value, but the latter can't handle the situation correctly. Make 'val' unsigned long long as what kstrtoull() takes, this will eliminate the compile warning on no 64-bit architectures. Link: https://lkml.kernel.org/r/1605341356-11872-1-git-send-email-yangyicong@hisilicon.com Fixes: f7b88631a897 ("fs/libfs.c: fix simple_attr_write() on 32bit machines") Signed-off-by: Yicong Yang Cc: Al Viro Signed-off-by: Andrew Morton --- fs/libfs.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/fs/libfs.c~libfs-fix-error-cast-of-negative-value-in-simple_attr_write +++ a/fs/libfs.c @@ -959,7 +959,7 @@ ssize_t simple_attr_write(struct file *f size_t len, loff_t *ppos) { struct simple_attr *attr; - u64 val; + unsigned long long val; size_t size; ssize_t ret; @@ -977,7 +977,9 @@ ssize_t simple_attr_write(struct file *f goto out; attr->set_buf[size] = '\0'; - val = simple_strtoll(attr->set_buf, NULL, 0); + ret = kstrtoull(attr->set_buf, 0, &val); + if (ret) + goto out; ret = attr->set(attr->data, val); if (ret == 0) ret = len; /* on success, claim we got the whole input */ _