From patchwork Wed May 18 09:38:29 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zhang Jianhua X-Patchwork-Id: 12853450 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A7F54C433FE for ; Wed, 18 May 2022 09:42:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234510AbiERJmJ (ORCPT ); Wed, 18 May 2022 05:42:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44148 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234615AbiERJke (ORCPT ); Wed, 18 May 2022 05:40:34 -0400 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 984D714A27A; Wed, 18 May 2022 02:40:01 -0700 (PDT) Received: from canpemm500005.china.huawei.com (unknown [172.30.72.54]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4L37H213JpzhZHF; Wed, 18 May 2022 17:39:10 +0800 (CST) Received: from huawei.com (10.67.174.96) by canpemm500005.china.huawei.com (7.192.104.229) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Wed, 18 May 2022 17:39:59 +0800 From: Zhang Jianhua To: , CC: , Subject: [PATCH -next] fs-verity: Use struct_size() helper in fsverity_ioctl_measure() Date: Wed, 18 May 2022 17:38:29 +0800 Message-ID: <20220518093829.2248801-1-chris.zjh@huawei.com> X-Mailer: git-send-email 2.31.0 MIME-Version: 1.0 X-Originating-IP: [10.67.174.96] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To canpemm500005.china.huawei.com (7.192.104.229) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-fscrypt@vger.kernel.org Make use of the struct_size() helper instead of an open-coded version, in order to avoid any potential type mistakes or integer overflows that, in the worst scenario, could lead to heap overflows. Also, address the following sparse warnings: fs/verity/measure.c:48:9: warning: using sizeof on a flexible structure fs/verity/measure.c:52:38: warning: using sizeof on a flexible structure Signed-off-by: Zhang Jianhua --- fs/verity/measure.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/fs/verity/measure.c b/fs/verity/measure.c index e99c00350c28..4a388116d0de 100644 --- a/fs/verity/measure.c +++ b/fs/verity/measure.c @@ -27,6 +27,7 @@ int fsverity_ioctl_measure(struct file *filp, void __user *_uarg) const struct fsverity_info *vi; const struct fsverity_hash_alg *hash_alg; struct fsverity_digest arg; + size_t arg_size = struct_size(&arg, digest, 0); vi = fsverity_get_info(inode); if (!vi) @@ -44,11 +45,11 @@ int fsverity_ioctl_measure(struct file *filp, void __user *_uarg) if (arg.digest_size < hash_alg->digest_size) return -EOVERFLOW; - memset(&arg, 0, sizeof(arg)); + memset(&arg, 0, arg_size); arg.digest_algorithm = hash_alg - fsverity_hash_algs; arg.digest_size = hash_alg->digest_size; - if (copy_to_user(uarg, &arg, sizeof(arg))) + if (copy_to_user(uarg, &arg, arg_size)) return -EFAULT; if (copy_to_user(uarg->digest, vi->file_digest, hash_alg->digest_size))