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=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 45BD1C43460 for ; Mon, 17 May 2021 23:03:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0BCF1610A1 for ; Mon, 17 May 2021 23:03:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239158AbhEQXE1 convert rfc822-to-8bit (ORCPT ); Mon, 17 May 2021 19:04:27 -0400 Received: from mga04.intel.com ([192.55.52.120]:57272 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233727AbhEQXE0 (ORCPT ); Mon, 17 May 2021 19:04:26 -0400 IronPort-SDR: 38crZ//stfzvLseKQe4WoucvANo6o4P4AdVEY2n3umk2BgQgzTqLI0YLTb3+Sf//ovZwufyDvW MzLlP+MEMdbw== X-IronPort-AV: E=McAfee;i="6200,9189,9987"; a="198634054" X-IronPort-AV: E=Sophos;i="5.82,307,1613462400"; d="scan'208";a="198634054" Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 May 2021 16:03:09 -0700 IronPort-SDR: OIstmQu8Q/u81oyekW2G6+Iz9ZP6crpBxN2ygL0exMrRJ7CsVX8Fd13ZIag7SOOEEOEt4YEOt2 pjhRMZ1N9tlA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.82,307,1613462400"; d="scan'208";a="626835304" Received: from fmsmsx605.amr.corp.intel.com ([10.18.126.85]) by fmsmga006.fm.intel.com with ESMTP; 17 May 2021 16:03:09 -0700 Received: from fmsmsx612.amr.corp.intel.com (10.18.126.92) by fmsmsx605.amr.corp.intel.com (10.18.126.85) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2242.4; Mon, 17 May 2021 16:03:09 -0700 Received: from fmsmsx612.amr.corp.intel.com (10.18.126.92) by fmsmsx612.amr.corp.intel.com (10.18.126.92) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2242.4; Mon, 17 May 2021 16:03:09 -0700 Received: from fmsmsx612.amr.corp.intel.com ([10.18.126.92]) by fmsmsx612.amr.corp.intel.com ([10.18.126.92]) with mapi id 15.01.2242.008; Mon, 17 May 2021 16:03:09 -0700 From: "Saleem, Shiraz" To: Weihang Li , "dledford@redhat.com" , "jgg@nvidia.com" CC: "leon@kernel.org" , "linux-rdma@vger.kernel.org" , "linuxarm@huawei.com" Subject: RE: [PATCH for-next 1/6] RDMA/core: Use refcount_t instead of atomic_t for reference counting Thread-Topic: [PATCH for-next 1/6] RDMA/core: Use refcount_t instead of atomic_t for reference counting Thread-Index: AQHXSGaUU9wSirm01EKYaz/j80EGOaroLwcA Date: Mon, 17 May 2021 23:03:09 +0000 Message-ID: References: <1620958299-4869-1-git-send-email-liweihang@huawei.com> <1620958299-4869-2-git-send-email-liweihang@huawei.com> In-Reply-To: <1620958299-4869-2-git-send-email-liweihang@huawei.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: dlp-product: dlpe-windows dlp-reaction: no-action dlp-version: 11.5.1.3 x-originating-ip: [10.1.200.100] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org > Subject: [PATCH for-next 1/6] RDMA/core: Use refcount_t instead of atomic_t for > reference counting > > The refcount_t API will WARN on underflow and overflow of a reference counter, > and avoid use-after-free risks. Increase refcount_t from 0 to 1 is regarded as there > is a risk about use-after-free. So it should be set to 1 directly during initialization. > > Signed-off-by: Weihang Li > --- > drivers/infiniband/core/iwcm.c | 9 ++++----- > drivers/infiniband/core/iwcm.h | 2 +- > drivers/infiniband/core/iwpm_util.c | 12 ++++++++---- > drivers/infiniband/core/iwpm_util.h | 2 +- > drivers/infiniband/core/mad_priv.h | 2 +- > drivers/infiniband/core/multicast.c | 30 +++++++++++++++--------------- > drivers/infiniband/core/uverbs.h | 2 +- > drivers/infiniband/core/uverbs_main.c | 12 ++++++------ > 8 files changed, 37 insertions(+), 34 deletions(-) > [...] > @@ -589,9 +589,9 @@ static struct mcast_group *acquire_group(struct > mcast_port *port, > kfree(group); > group = cur_group; > } else > - atomic_inc(&port->refcount); > + refcount_inc(&port->refcount); > found: > - atomic_inc(&group->refcount); > + refcount_inc(&group->refcount); Seems like there is refcount_inc with refcount = 0 when the group is first created? > spin_unlock_irqrestore(&port->lock, flags); > return group; > }