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=-16.4 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 2226FC433E0 for ; Sun, 3 Jan 2021 05:51:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D67A620795 for ; Sun, 3 Jan 2021 05:51:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726236AbhACFvQ (ORCPT ); Sun, 3 Jan 2021 00:51:16 -0500 Received: from mga17.intel.com ([192.55.52.151]:3749 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725275AbhACFvP (ORCPT ); Sun, 3 Jan 2021 00:51:15 -0500 IronPort-SDR: UedIH9wEWaFzvH3jRUuwCB7Uu4FB0Qh3sKHmdxRHKrhxuPfL9wnLSqabIt6UrmLKXZ4oGZXO6e BzLQ9NZti7kQ== X-IronPort-AV: E=McAfee;i="6000,8403,9852"; a="156639442" X-IronPort-AV: E=Sophos;i="5.78,471,1599548400"; d="scan'208";a="156639442" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Jan 2021 21:49:30 -0800 IronPort-SDR: AZJ3z3f/50BAGBVx8UDBX5zmZx51m+XlxeNwiNuVsZHKwRwbKAFslm7Yam1MbcUTkq6wc4xLWU WtLbyvtH3ijQ== X-IronPort-AV: E=Sophos;i="5.78,471,1599548400"; d="scan'208";a="377891336" Received: from blu2-mobl3.ccr.corp.intel.com (HELO [10.255.29.85]) ([10.255.29.85]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Jan 2021 21:49:27 -0800 Cc: baolu.lu@linux.intel.com, kjlu@umn.edu, David Woodhouse , Joerg Roedel , Will Deacon , Jiang Liu , Thomas Gleixner , iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] iommu/intel: Fix memleak in intel_irq_remapping_alloc To: dinghao.liu@zju.edu.cn References: <20210102095029.29053-1-dinghao.liu@zju.edu.cn> <18add30d-a830-c531-6fd2-58a1898b157f@linux.intel.com> <50870a42.15f1a.176c66eaf92.Coremail.dinghao.liu@zju.edu.cn> From: Lu Baolu Message-ID: <6e1ce9ac-ac17-2b16-84d3-a18c011768f2@linux.intel.com> Date: Sun, 3 Jan 2021 13:49:25 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.6.0 MIME-Version: 1.0 In-Reply-To: <50870a42.15f1a.176c66eaf92.Coremail.dinghao.liu@zju.edu.cn> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2021/1/3 12:08, dinghao.liu@zju.edu.cn wrote: >> Hi, >> >> On 2021/1/2 17:50, Dinghao Liu wrote: >>> When irq_domain_get_irq_data() or irqd_cfg() fails >>> meanwhile i == 0, data allocated by kzalloc() has not >>> been freed before returning, which leads to memleak. >>> >>> Fixes: b106ee63abccb ("irq_remapping/vt-d: Enhance Intel IR driver to support hierarchical irqdomains") >>> Signed-off-by: Dinghao Liu >>> --- >>> drivers/iommu/intel/irq_remapping.c | 2 ++ >>> 1 file changed, 2 insertions(+) >>> >>> diff --git a/drivers/iommu/intel/irq_remapping.c b/drivers/iommu/intel/irq_remapping.c >>> index aeffda92b10b..cdaeed36750f 100644 >>> --- a/drivers/iommu/intel/irq_remapping.c >>> +++ b/drivers/iommu/intel/irq_remapping.c >>> @@ -1354,6 +1354,8 @@ static int intel_irq_remapping_alloc(struct irq_domain *domain, >>> irq_cfg = irqd_cfg(irq_data); >>> if (!irq_data || !irq_cfg) { >>> ret = -EINVAL; >>> + kfree(data); >>> + data = NULL; >> >> Do you need to check (i == 0) here? @data will not be used anymore as it >> goes to out branch, why setting it to NULL here? >> > > data will be passed to ire_data->chip_data when i == 0 and > intel_free_irq_resources() will free it on failure. Thus I Isn't it going to "goto out_free_data"? If "i == 0", the allocated @data won't be freed by intel_free_irq_resources(), hence memory leaking. Does this patch aim to fix this? Best regards, baolu > set it to NULL to prevent double-free. However, if we add > a check (i == 0) here, we will not need to set it to NULL. > If this is better, I will resend a new patch soon. > > Regards, > Dinghao >