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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT 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 010E2C4321D for ; Fri, 24 Aug 2018 01:16:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A2DA121557 for ; Fri, 24 Aug 2018 01:16:16 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A2DA121557 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=embeddedor.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727134AbeHXEsa (ORCPT ); Fri, 24 Aug 2018 00:48:30 -0400 Received: from gateway22.websitewelcome.com ([192.185.47.168]:39544 "EHLO gateway22.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725945AbeHXEs3 (ORCPT ); Fri, 24 Aug 2018 00:48:29 -0400 Received: from cm17.websitewelcome.com (cm17.websitewelcome.com [100.42.49.20]) by gateway22.websitewelcome.com (Postfix) with ESMTP id 874627A70 for ; Thu, 23 Aug 2018 20:16:13 -0500 (CDT) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id t0hUf3Jz2PvAdt0hlf1hqA; Thu, 23 Aug 2018 20:16:13 -0500 X-Authority-Reason: nr=8 Received: from [189.250.73.28] (port=44186 helo=embeddedor) by gator4166.hostgator.com with esmtpa (Exim 4.91) (envelope-from ) id 1ft0hT-003Wek-Ek; Thu, 23 Aug 2018 20:15:43 -0500 Date: Thu, 23 Aug 2018 20:15:40 -0500 From: "Gustavo A. R. Silva" To: Johannes Berg , Emmanuel Grumbach , Luca Coelho , Intel Linux Wireless , Kalle Valo , "David S. Miller" Cc: linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Kees Cook , "Gustavo A. R. Silva" Subject: [PATCH] iwlwifi: d3: use struct_size() in kzalloc() Message-ID: <20180824011540.GA25716@embeddedor.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.24 (2015-08-30) 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: 189.250.73.28 X-Source-L: No X-Exim-ID: 1ft0hT-003Wek-Ek X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [189.250.73.28]:44186 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 41 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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; void *entry[]; }; instance = kzalloc(sizeof(struct foo) + sizeof(void *) * count, 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 issue was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva --- drivers/net/wireless/intel/iwlwifi/mvm/d3.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/d3.c b/drivers/net/wireless/intel/iwlwifi/mvm/d3.c index 79bdae9..6960318 100644 --- a/drivers/net/wireless/intel/iwlwifi/mvm/d3.c +++ b/drivers/net/wireless/intel/iwlwifi/mvm/d3.c @@ -1769,8 +1769,7 @@ static void iwl_mvm_query_netdetect_reasons(struct iwl_mvm *mvm, n_matches = 0; } - net_detect = kzalloc(sizeof(*net_detect) + - (n_matches * sizeof(net_detect->matches[0])), + net_detect = kzalloc(struct_size(net_detect, matches, n_matches), GFP_KERNEL); if (!net_detect || !n_matches) goto out_report_nd; @@ -1785,8 +1784,7 @@ static void iwl_mvm_query_netdetect_reasons(struct iwl_mvm *mvm, for (j = 0; j < SCAN_OFFLOAD_MATCHING_CHANNELS_LEN; j++) n_channels += hweight8(fw_match->matching_channels[j]); - match = kzalloc(sizeof(*match) + - (n_channels * sizeof(*match->channels)), + match = kzalloc(struct_size(match, channels, n_channels), GFP_KERNEL); if (!match) goto out_report_nd; -- 2.7.4