From patchwork Tue May 25 06:51:37 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Weihang Li X-Patchwork-Id: 12278009 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=-16.8 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,USER_AGENT_GIT 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 AAE11C4707F for ; Tue, 25 May 2021 06:51:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8D0F4611B0 for ; Tue, 25 May 2021 06:51:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231415AbhEYGx1 (ORCPT ); Tue, 25 May 2021 02:53:27 -0400 Received: from szxga04-in.huawei.com ([45.249.212.190]:5696 "EHLO szxga04-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231365AbhEYGx0 (ORCPT ); Tue, 25 May 2021 02:53:26 -0400 Received: from dggems701-chm.china.huawei.com (unknown [172.30.72.59]) by szxga04-in.huawei.com (SkyGuard) with ESMTP id 4Fq4S00s2kz1BQGt; Tue, 25 May 2021 14:49:04 +0800 (CST) Received: from dggema753-chm.china.huawei.com (10.1.198.195) by dggems701-chm.china.huawei.com (10.3.19.178) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256) id 15.1.2176.2; Tue, 25 May 2021 14:51:54 +0800 Received: from localhost.localdomain (10.69.192.56) by dggema753-chm.china.huawei.com (10.1.198.195) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2176.2; Tue, 25 May 2021 14:51:54 +0800 From: Weihang Li To: , CC: , , , Weihang Li Subject: [PATCH v3 for-next 06/13] RDMA/core: Use refcount_t instead of atomic_t on refcount of mcast_group Date: Tue, 25 May 2021 14:51:37 +0800 Message-ID: <1621925504-33019-7-git-send-email-liweihang@huawei.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1621925504-33019-1-git-send-email-liweihang@huawei.com> References: <1621925504-33019-1-git-send-email-liweihang@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.69.192.56] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To dggema753-chm.china.huawei.com (10.1.198.195) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org 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/multicast.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) diff --git a/drivers/infiniband/core/multicast.c b/drivers/infiniband/core/multicast.c index a236532..17abc21 100644 --- a/drivers/infiniband/core/multicast.c +++ b/drivers/infiniband/core/multicast.c @@ -103,7 +103,7 @@ struct mcast_group { struct list_head active_list; struct mcast_member *last_join; int members[NUM_JOIN_MEMBERSHIP_TYPES]; - atomic_t refcount; + refcount_t refcount; enum mcast_group_state state; struct ib_sa_query *query; u16 pkey_index; @@ -188,7 +188,7 @@ static void release_group(struct mcast_group *group) unsigned long flags; spin_lock_irqsave(&port->lock, flags); - if (atomic_dec_and_test(&group->refcount)) { + if (refcount_dec_and_test(&group->refcount)) { rb_erase(&group->node, &port->table); spin_unlock_irqrestore(&port->lock, flags); kfree(group); @@ -212,7 +212,7 @@ static void queue_join(struct mcast_member *member) list_add_tail(&member->list, &group->pending_list); if (group->state == MCAST_IDLE) { group->state = MCAST_BUSY; - atomic_inc(&group->refcount); + refcount_inc(&group->refcount); queue_work(mcast_wq, &group->work); } spin_unlock_irqrestore(&group->lock, flags); @@ -565,8 +565,11 @@ static struct mcast_group *acquire_group(struct mcast_port *port, if (!is_mgid0) { spin_lock_irqsave(&port->lock, flags); group = mcast_find(port, mgid); - if (group) + if (group) { + refcount_inc(&group->refcount); goto found; + } + spin_unlock_irqrestore(&port->lock, flags); } @@ -590,8 +593,10 @@ static struct mcast_group *acquire_group(struct mcast_port *port, group = cur_group; } else refcount_inc(&port->refcount); + + refcount_set(&group->refcount, 1); + found: - atomic_inc(&group->refcount); spin_unlock_irqrestore(&port->lock, flags); return group; } @@ -780,7 +785,7 @@ static void mcast_groups_event(struct mcast_port *port, group = rb_entry(node, struct mcast_group, node); spin_lock(&group->lock); if (group->state == MCAST_IDLE) { - atomic_inc(&group->refcount); + refcount_inc(&group->refcount); queue_work(mcast_wq, &group->work); } if (group->state != MCAST_GROUP_ERROR)