From patchwork Mon Nov 23 12:22:11 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 331359 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=-18.8 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, URIBL_BLOCKED, 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 9028EC64E7D for ; Mon, 23 Nov 2020 12:23:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 541592076E for ; Mon, 23 Nov 2020 12:23:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="1JwkofPs" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728895AbgKWMXZ (ORCPT ); Mon, 23 Nov 2020 07:23:25 -0500 Received: from mail.kernel.org ([198.145.29.99]:60352 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726529AbgKWMXY (ORCPT ); Mon, 23 Nov 2020 07:23:24 -0500 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (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 D90BA2137B; Mon, 23 Nov 2020 12:23:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1606134203; bh=vfkvJNd1tRHOibulvnIWtgRVDfCN7kcbl9HlsaYcNGw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1JwkofPsLbtdjlYUaAbGA+fascnAN/Hwa7PfPxez8VdfxosQCNYnTZWzH6YFl06t9 If6x3vtBQYC2eWFadpQB2fkACuPjJTFWJqGijfdNrVO7YvzAUJlOOOHffmk1ODcQPi /jYV0pqPufGe2XV5ZWCcLRcmguQAgm/+WvEgnB2E= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Yicong Yang , Andrew Morton , Al Viro , Linus Torvalds , Sasha Levin Subject: [PATCH 4.4 25/38] libfs: fix error cast of negative value in simple_attr_write() Date: Mon, 23 Nov 2020 13:22:11 +0100 Message-Id: <20201123121805.503998800@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201123121804.306030358@linuxfoundation.org> References: <20201123121804.306030358@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Yicong Yang [ Upstream commit 488dac0c9237647e9b8f788b6a342595bfa40bda ] 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. Fixes: f7b88631a897 ("fs/libfs.c: fix simple_attr_write() on 32bit machines") Signed-off-by: Yicong Yang Signed-off-by: Andrew Morton Cc: Al Viro Link: https://lkml.kernel.org/r/1605341356-11872-1-git-send-email-yangyicong@hisilicon.com Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- fs/libfs.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/fs/libfs.c b/fs/libfs.c index a33e95f8729bf..01e9cae5b1601 100644 --- a/fs/libfs.c +++ b/fs/libfs.c @@ -827,7 +827,7 @@ ssize_t simple_attr_write(struct file *file, const char __user *buf, size_t len, loff_t *ppos) { struct simple_attr *attr; - u64 val; + unsigned long long val; size_t size; ssize_t ret; @@ -845,7 +845,9 @@ ssize_t simple_attr_write(struct file *file, const char __user *buf, 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 */