From patchwork Wed May 29 16:53:43 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Gustavo A. R. Silva" X-Patchwork-Id: 10967361 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id E74731395 for ; Wed, 29 May 2019 17:17:51 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D8A3C286B1 for ; Wed, 29 May 2019 17:17:51 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id CCB46287E9; Wed, 29 May 2019 17:17:51 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7E49F286B9 for ; Wed, 29 May 2019 17:17:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726099AbfE2RRu (ORCPT ); Wed, 29 May 2019 13:17:50 -0400 Received: from gateway20.websitewelcome.com ([192.185.59.4]:23512 "EHLO gateway20.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725917AbfE2RRu (ORCPT ); Wed, 29 May 2019 13:17:50 -0400 X-Greylist: delayed 1445 seconds by postgrey-1.27 at vger.kernel.org; Wed, 29 May 2019 13:17:50 EDT Received: from cm11.websitewelcome.com (cm11.websitewelcome.com [100.42.49.5]) by gateway20.websitewelcome.com (Postfix) with ESMTP id 663F2400C6FD4 for ; Wed, 29 May 2019 10:53:24 -0500 (CDT) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id W1phhRrL6dnCeW1phh6cK0; Wed, 29 May 2019 11:53:45 -0500 X-Authority-Reason: nr=8 Received: from [189.250.47.159] (port=50894 helo=embeddedor) by gator4166.hostgator.com with esmtpa (Exim 4.91) (envelope-from ) id 1hW1pf-002Frw-RX; Wed, 29 May 2019 11:53:44 -0500 Date: Wed, 29 May 2019 11:53:43 -0500 From: "Gustavo A. R. Silva" To: Mimi Zohar , Dmitry Kasatkin , James Morris , "Serge E. Hallyn" Cc: linux-integrity@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" Subject: [PATCH] ima: use struct_size() in kzalloc() Message-ID: <20190529165343.GA2584@embeddedor> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.9.4 (2018-02-28) X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - gator4166.hostgator.com X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - embeddedor.com X-BWhitelist: no X-Source-IP: 189.250.47.159 X-Source-L: No X-Exim-ID: 1hW1pf-002Frw-RX X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [189.250.47.159]:50894 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 15 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: X-Virus-Scanned: ClamAV using ClamSMTP One of the more common cases of allocation size calculations is finding the size of a structure that has a zero-sized array at the end, along with memory for some number of elements for that array. For example: struct foo { int stuff; struct boo entry[]; }; instance = kzalloc(sizeof(struct foo) + count * sizeof(struct boo), GFP_KERNEL); Instead of leaving these open-coded and prone to type mistakes, we can now use the new struct_size() helper: instance = kzalloc(struct_size(instance, entry, count), GFP_KERNEL); This code was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva --- security/integrity/ima/ima_template.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/security/integrity/ima/ima_template.c b/security/integrity/ima/ima_template.c index b631b8bc7624..b945dff2ed14 100644 --- a/security/integrity/ima/ima_template.c +++ b/security/integrity/ima/ima_template.c @@ -281,9 +281,8 @@ static int ima_restore_template_data(struct ima_template_desc *template_desc, int ret = 0; int i; - *entry = kzalloc(sizeof(**entry) + - template_desc->num_fields * sizeof(struct ima_field_data), - GFP_NOFS); + *entry = kzalloc(struct_size(*entry, template_data, + template_desc->num_fields), GFP_NOFS); if (!*entry) return -ENOMEM;