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=-15.2 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,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable 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 363A2C43460 for ; Wed, 19 May 2021 11:20:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 152AD6108B for ; Wed, 19 May 2021 11:20:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349736AbhESLVp (ORCPT ); Wed, 19 May 2021 07:21:45 -0400 Received: from szxga05-in.huawei.com ([45.249.212.191]:3029 "EHLO szxga05-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346140AbhESLVj (ORCPT ); Wed, 19 May 2021 07:21:39 -0400 Received: from dggems705-chm.china.huawei.com (unknown [172.30.72.58]) by szxga05-in.huawei.com (SkyGuard) with ESMTP id 4FlVgd3wNRzQpYR; Wed, 19 May 2021 19:16:45 +0800 (CST) Received: from lhreml724-chm.china.huawei.com (10.201.108.75) by dggems705-chm.china.huawei.com (10.3.19.182) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Wed, 19 May 2021 19:20:15 +0800 Received: from [10.47.87.246] (10.47.87.246) by lhreml724-chm.china.huawei.com (10.201.108.75) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Wed, 19 May 2021 12:20:12 +0100 Subject: Re: [PATCH -next] scsi: hisi_sas: drop free_irq of devm_request_irq allocated irq To: Yang Yingliang , , CC: , , chenxiang , "luojiaxing@huawei.com" References: <20210518130902.1307494-1-yangyingliang@huawei.com> <30e9c7d4-75c6-8cbc-7a27-d406eae01dad@huawei.com> From: John Garry Message-ID: <245d0847-bddd-2ea7-d4bc-9c4be2d26b45@huawei.com> Date: Wed, 19 May 2021 12:19:09 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.1.2 MIME-Version: 1.0 In-Reply-To: <30e9c7d4-75c6-8cbc-7a27-d406eae01dad@huawei.com> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-Originating-IP: [10.47.87.246] X-ClientProxiedBy: lhreml745-chm.china.huawei.com (10.201.108.195) To lhreml724-chm.china.huawei.com (10.201.108.75) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 19/05/2021 04:36, Yang Yingliang wrote: > > On 2021/5/18 23:34, John Garry wrote: >> On 18/05/2021 14:09, Yang Yingliang wrote: >>> irq allocated with devm_request_irq should not be freed using >>> free_irq, because doing so causes a dangling pointer, and a >>> subsequent double free. >>> >>> Reported-by: Hulk Robot >>> Signed-off-by: Yang Yingliang >>> --- >>>   drivers/scsi/hisi_sas/hisi_sas_v3_hw.c | 6 +++--- >>>   1 file changed, 3 insertions(+), 3 deletions(-) >>> >>> diff --git a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c >>> b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c >>> index 499c770d405c..684f762bcfb3 100644 >>> --- a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c >>> +++ b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c >>> @@ -4811,9 +4811,9 @@ hisi_sas_v3_destroy_irqs(struct pci_dev *pdev, >>> struct hisi_hba *hisi_hba) >>>   { >>>       int i; >>>   -    free_irq(pci_irq_vector(pdev, 1), hisi_hba); >>> -    free_irq(pci_irq_vector(pdev, 2), hisi_hba); >>> -    free_irq(pci_irq_vector(pdev, 11), hisi_hba); >>> +    devm_free_irq(&pdev->dev, pci_irq_vector(pdev, 1), hisi_hba); >>> +    devm_free_irq(&pdev->dev, pci_irq_vector(pdev, 2), hisi_hba); >>> +    devm_free_irq(&pdev->dev, pci_irq_vector(pdev, 11), hisi_hba); >>>       for (i = 0; i < hisi_hba->cq_nvecs; i++) { >>>           struct hisi_sas_cq *cq = &hisi_hba->cq[i]; >>>           int nr = hisi_sas_intr_conv ? 16 : 16 + i; >>> >> >> Does the free_irq(pci_irq_vector(pdev, nr, cq)) call also need to >> change (not shown)? > Yes, I missed that, it should be changed too. So I think that we need this addition: devm_free_irq(&pdev->dev, pci_irq_vector(pdev, nr), cq); >> >> Having said that, why have these at all if we use devm_request_irq()? >> devm_irq_release() calls free_irq(). > I keep the original logic here, only avoid double free. Kasan doesn't complain. Anyway, I think we can't rely on device-managed method (for calling free_irq()) as it conflicts with pci free vectors call. I thought that someone was developed a device-managed version of that (pci_alloc_irq_vectors()). Anyway, please proceed with your change, but with the suggested addition. Thanks