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=-16.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 0CAA0C433DB for ; Thu, 11 Mar 2021 09:22:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7536164FB0 for ; Thu, 11 Mar 2021 09:22:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231629AbhCKJWW (ORCPT ); Thu, 11 Mar 2021 04:22:22 -0500 Received: from mail.kernel.org ([198.145.29.99]:48202 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231965AbhCKJWH (ORCPT ); Thu, 11 Mar 2021 04:22:07 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 610A264E5F; Thu, 11 Mar 2021 09:22:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1615454527; bh=QRVck+IIsi24TGqXEvxqoBtyhlaKGyxDG/OywFja2Vk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=jdq0+S96sulLfadpU8BIgL3NRrGUddU63uusQBKkKf2lVLjDfRuRhb6Ncf1dvrwH2 VPPYzO8pW6lzbR0DHD3fMZJweKB5529IOqtEDNAZTTe3AnPWoARCHOdA8eEdRYzQOx xW74JlEURfReF5oKjznIF8hJ7QPQqb80kOE39U/5+qjRPicPtE6moM68/p0I910EGi 2TQIWmzY/PZ64ta/JZOuXdUU0ObdgDuwxlSTZrUouXOiSq7bNqSvqFqVjTw59l5Ixx UKEWd9qMyrlaumQ/V95hk/xq1t5mjPNkqWu0glEFedfK3tcqC8LM4F89rRfAMTI3vX Lu6xfOiIHcqlA== Date: Thu, 11 Mar 2021 11:22:03 +0200 From: Leon Romanovsky To: Lv Yunlong Cc: dledford@redhat.com, jgg@ziepe.ca, linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] infiniband/core: Fix a use after free in cm_work_handler Message-ID: References: <20210311022153.3757-1-lyl2019@mail.ustc.edu.cn> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210311022153.3757-1-lyl2019@mail.ustc.edu.cn> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Mar 10, 2021 at 06:21:53PM -0800, Lv Yunlong wrote: > In cm_work_handler, it calls destory_cm_id() to release > the initial reference of cm_id_priv taken by iw_create_cm_id() > and free the cm_id_priv. After destory_cm_id(), iwcm_deref_id > (cm_id_priv) will be called and cause a use after free. > > Fixes: 59c68ac31e15a ("iw_cm: free cm_id resources on the last deref") > Signed-off-by: Lv Yunlong > --- > drivers/infiniband/core/iwcm.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/drivers/infiniband/core/iwcm.c b/drivers/infiniband/core/iwcm.c > index da8adadf4755..cb6b4ac45e21 100644 > --- a/drivers/infiniband/core/iwcm.c > +++ b/drivers/infiniband/core/iwcm.c > @@ -1035,8 +1035,10 @@ static void cm_work_handler(struct work_struct *_work) > > if (!test_bit(IWCM_F_DROP_EVENTS, &cm_id_priv->flags)) { > ret = process_event(cm_id_priv, &levent); > - if (ret) > + if (ret) { > destroy_cm_id(&cm_id_priv->id); > + return; The destroy_cm_id() is called to free ->id and not cm_id_priv. This "return" leaks cm_id_priv now and what "a use after free" do you see? > + } > } else > pr_debug("dropping event %d\n", levent.event); > if (iwcm_deref_id(cm_id_priv)) > -- > 2.25.1 > >