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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT 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 CB115C43470 for ; Wed, 12 May 2021 19:23:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 993A7613FE for ; Wed, 12 May 2021 19:23:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1379393AbhELTTl (ORCPT ); Wed, 12 May 2021 15:19:41 -0400 Received: from mail.kernel.org ([198.145.29.99]:50498 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244552AbhELQut (ORCPT ); Wed, 12 May 2021 12:50:49 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 9169961C77; Wed, 12 May 2021 16:16:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1620836209; bh=33ODD0I24enfDgzrAF6996/yVOfNCM+RxRup5ieFN4o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=uzownORWytgco3Q4TZ8fezuCajW7AKjDOyyI/FlYzf0ZppLaCcM3yrXy+YQTp+Jv5 WkVBQrtyYTQkwKjQ62nkpaLJ8D4j9SExWMnAh0cb3WNlGUrcwdz0yXrUka2Ewu92xH yuFN/be0XCWKmVmmCWql2batAwP1kBUyI5VtL/6c= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Lv Yunlong , Bernard Metzler , Jason Gunthorpe , Sasha Levin Subject: [PATCH 5.12 655/677] RDMA/siw: Fix a use after free in siw_alloc_mr Date: Wed, 12 May 2021 16:51:41 +0200 Message-Id: <20210512144859.129602096@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210512144837.204217980@linuxfoundation.org> References: <20210512144837.204217980@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Lv Yunlong [ Upstream commit 3093ee182f01689b89e9f8797b321603e5de4f63 ] 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). My patch moves "mr->mem = mem" behind the if (xa_alloc_cyclic(..)<0) {} section, to avoid the uaf. Fixes: 2251334dcac9 ("rdma/siw: application buffer management") Link: https://lore.kernel.org/r/20210426011647.3561-1-lyl2019@mail.ustc.edu.cn Signed-off-by: Lv Yunlong Reviewed-by: Bernard Metzler Signed-off-by: Jason Gunthorpe Signed-off-by: Sasha Levin --- drivers/infiniband/sw/siw/siw_mem.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/infiniband/sw/siw/siw_mem.c b/drivers/infiniband/sw/siw/siw_mem.c index 34a910cf0edb..61c17db70d65 100644 --- a/drivers/infiniband/sw/siw/siw_mem.c +++ b/drivers/infiniband/sw/siw/siw_mem.c @@ -106,8 +106,6 @@ int siw_mr_add_mem(struct siw_mr *mr, struct ib_pd *pd, void *mem_obj, mem->perms = rights & IWARP_ACCESS_MASK; kref_init(&mem->ref); - mr->mem = mem; - get_random_bytes(&next, 4); next &= 0x00ffffff; @@ -116,6 +114,8 @@ int siw_mr_add_mem(struct siw_mr *mr, struct ib_pd *pd, void *mem_obj, kfree(mem); return -ENOMEM; } + + mr->mem = mem; /* Set the STag index part */ mem->stag = id << 8; mr->base_mr.lkey = mr->base_mr.rkey = mem->stag; -- 2.30.2