From patchwork Thu Aug 29 17:29:16 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: 11122197 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 368D61399 for ; Thu, 29 Aug 2019 18:12:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 143032189D for ; Thu, 29 Aug 2019 18:12:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=embeddedor.com header.i=@embeddedor.com header.b="L2GNazUZ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727125AbfH2SMy (ORCPT ); Thu, 29 Aug 2019 14:12:54 -0400 Received: from gateway33.websitewelcome.com ([192.185.146.130]:34838 "EHLO gateway33.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726661AbfH2SMy (ORCPT ); Thu, 29 Aug 2019 14:12:54 -0400 X-Greylist: delayed 1484 seconds by postgrey-1.27 at vger.kernel.org; Thu, 29 Aug 2019 14:12:53 EDT Received: from cm11.websitewelcome.com (cm11.websitewelcome.com [100.42.49.5]) by gateway33.websitewelcome.com (Postfix) with ESMTP id 321E457D59 for ; Thu, 29 Aug 2019 12:29:19 -0500 (CDT) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id 3OEZik3nAdnCe3OEZi7g54; Thu, 29 Aug 2019 12:29:19 -0500 X-Authority-Reason: nr=8 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=embeddedor.com; s=default; h=Content-Type:MIME-Version:Message-ID:Subject: Cc:To:From:Date:Sender:Reply-To:Content-Transfer-Encoding:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:In-Reply-To:References:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=aJiyb7UI2K/+R2F5a3fw1EU55SbvNGjQFMYnPqg0Gq4=; b=L2GNazUZvM+5uFV9vAPkne/b+V VCYDR6dk/keOSuL7t2Ng6N1LuKCPYSDSgz3Q29kbR5AbTVVHhqfnlixvTZ+l59IE2T416t9h/2Ehk dPWLzEDR/sdRSe9+UUwp0iqG3rq7WkiU4O+jzUngKmVQBTcJJRyzPtGdmEh1gxVcjkRKtibbxpHau Yq7XwKT+IRk9FTtAs0NtZfp1/0KuvasEG9iEbH5p8OxCYHbRZmiP+3OYkVrz104HNV+n16cLndP9Z aaG3M/FVu/869oXP0fQ22APe6+XNNVUntMVC+DCeeU0zhbSW/WBIXLvwCkVT49oyH6kRqq3A0xjFk ec85EGXA==; Received: from [189.152.216.116] (port=41274 helo=embeddedor) by gator4166.hostgator.com with esmtpa (Exim 4.92) (envelope-from ) id 1i3OEX-000tZz-V9; Thu, 29 Aug 2019 12:29:18 -0500 Date: Thu, 29 Aug 2019 12:29:16 -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: ima_api: Use struct_size() in kzalloc() Message-ID: <20190829172916.GA10261@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: 189.152.216.116 X-Source-L: No X-Exim-ID: 1i3OEX-000tZz-V9 X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [189.152.216.116]:41274 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 13 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: 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 ima_template_entry { ... struct ima_field_data template_data[0]; /* template related data */ }; instance = kzalloc(sizeof(struct ima_template_entry) + count * sizeof(struct ima_field_data), GFP_NOFS); 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_NOFS); This code was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva --- security/integrity/ima/ima_api.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c index 65224474675b..610759fe63b8 100644 --- a/security/integrity/ima/ima_api.c +++ b/security/integrity/ima/ima_api.c @@ -45,8 +45,8 @@ int ima_alloc_init_template(struct ima_event_data *event_data, else template_desc = ima_template_desc_current(); - *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;