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 AC841C433ED for ; Sun, 25 Apr 2021 13:50:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7C98461363 for ; Sun, 25 Apr 2021 13:50:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230271AbhDYNuW (ORCPT ); Sun, 25 Apr 2021 09:50:22 -0400 Received: from mail.kernel.org ([198.145.29.99]:51392 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230214AbhDYNuU (ORCPT ); Sun, 25 Apr 2021 09:50:20 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 8E5F761363; Sun, 25 Apr 2021 13:49:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1619358580; bh=DGguM+dXVFEHhxP7ffgIr3ztEhgYe2f/QSBnkIvEibg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=QcdMxScWzLppYu6Iki2rSJNfB9zAS7qdSTLw6JxFGaxv9tJQc7z5EYcxMqJZQ1ynd 4BTi3TSmsEUfHXh6hTDVqYuAEsmKY8ZbDJfIUl7FhiHsy6EuxQa7VmIuXkewgIAeg6 jMnX4UBU3TBE7frm0bLeSt+cou2Cyk041SgCsFS/gT2AvSyoVUbBNfBXkfiWiMG5mO zrgM7/V8Y6n+X/x2JHmdJkqeOep+kQXzxgRkKchJpsV8xyNuZwRUNcDDOEx9WVBuVs rcW0HTPPP/1430SRaa3sHHMSh1tq5x1Bt8QPF+X4Go3dtW7Yu4Ja4B5tebdvMQJddJ hatRqgoAuxOcA== Date: Sun, 25 Apr 2021 16:49:36 +0300 From: Leon Romanovsky To: Lv Yunlong Cc: bmt@zurich.ibm.com, dledford@redhat.com, jgg@ziepe.ca, linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] rdma/siw: Fix a use after free in siw_alloc_mr Message-ID: References: <20210425132001.3994-1-lyl2019@mail.ustc.edu.cn> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210425132001.3994-1-lyl2019@mail.ustc.edu.cn> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Apr 25, 2021 at 06:20:01AM -0700, Lv Yunlong wrote: > Our code analyzer reported a uaf. > > In siw_alloc_mr, it calls siw_mr_add_mem(mr,..). In the implementation > of siw_mr_add_mem(), mem is assigned to mr->mem and then mem is freed > via kfree(mem) if xa_alloc_cyclic() failed. Here, mr->mem still point > to a freed object. After, the execution continue up to the err_out branch > of siw_alloc_mr, and the freed mr->mem is used in siw_mr_drop_mem(mr). > > Fixes: 2251334dcac9e ("rdma/siw: application buffer management") > Signed-off-by: Lv Yunlong > --- > drivers/infiniband/sw/siw/siw_mem.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/infiniband/sw/siw/siw_mem.c b/drivers/infiniband/sw/siw/siw_mem.c > index 34a910cf0edb..3bde3b6fca05 100644 > --- a/drivers/infiniband/sw/siw/siw_mem.c > +++ b/drivers/infiniband/sw/siw/siw_mem.c > @@ -114,6 +114,7 @@ int siw_mr_add_mem(struct siw_mr *mr, struct ib_pd *pd, void *mem_obj, > if (xa_alloc_cyclic(&sdev->mem_xa, &id, mem, limit, &next, > GFP_KERNEL) < 0) { > kfree(mem); > + mr->mem = NULL; > return -ENOMEM; > } Please move "mr->mem = mem;" assignment to be here, after if (...) {} section. Thanks > /* Set the STag index part */ > -- > 2.25.1 > >