From patchwork Mon Dec 2 11:12:46 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yann Droneaud X-Patchwork-Id: 3264781 Return-Path: X-Original-To: patchwork-linux-rdma@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id B4A0C9F3C2 for ; Mon, 2 Dec 2013 11:13:53 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id E9DC220306 for ; Mon, 2 Dec 2013 11:13:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C86E7202EB for ; Mon, 2 Dec 2013 11:13:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753288Ab3LBLNq (ORCPT ); Mon, 2 Dec 2013 06:13:46 -0500 Received: from smtp2-g21.free.fr ([212.27.42.2]:50191 "EHLO smtp2-g21.free.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752724Ab3LBLNq (ORCPT ); Mon, 2 Dec 2013 06:13:46 -0500 Received: from localhost.localdomain (unknown [37.163.28.200]) by smtp2-g21.free.fr (Postfix) with ESMTP id A398C4B000F; Mon, 2 Dec 2013 12:13:37 +0100 (CET) Received: from localhost.localdomain (localhost.localdomain [127.0.0.1]) by localhost.localdomain (8.14.7/8.14.7) with ESMTP id rB2BDYkL023901; Mon, 2 Dec 2013 12:13:34 +0100 Received: (from ydroneaud@localhost) by localhost.localdomain (8.14.7/8.14.7/Submit) id rB2BDXXt023900; Mon, 2 Dec 2013 12:13:33 +0100 From: Yann Droneaud To: Roland Dreier , linux-rdma@vger.kernel.org Cc: Or Gerlitz , Matan Barak , Yann Droneaud Subject: [PATCH v2 for v3.13 4/8] IB/uverbs: check reserved field in extended command header Date: Mon, 2 Dec 2013 12:12:46 +0100 Message-Id: <75adf09c5258445b66fc4e516199841b795d0f5e.1385981934.git.ydroneaud@opteya.com> X-Mailer: git-send-email 1.8.4.2 In-Reply-To: References: In-Reply-To: References: Sender: linux-rdma-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP As noted by Daniel Vetter in its article "Botching up ioctls"[1] "Check *all* unused fields and flags and all the padding for whether it's 0, and reject the ioctl if that's not the case. Otherwise your nice plan for future extensions is going right down the gutters since someone *will* submit an ioctl struct with random stack garbage in the yet unused parts. Which then bakes in the ABI that those fields can never be used for anything else but garbage." It's important to ensure that reserved fields are set to known value, so that it will be possible to use them latter to extend the ABI. The same reasonning apply to comp_mask field present in newer uverbs command: per commit 22878dbc9173, unsupported values in comp_mask are rejected. [1] http://blog.ffwll.ch/2013/11/botching-up-ioctls.html Link: http://marc.info/?i=cover.1385981934.git.ydroneaud@opteya.com Signed-off-by: Yann Droneaud --- drivers/infiniband/core/uverbs_main.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/infiniband/core/uverbs_main.c b/drivers/infiniband/core/uverbs_main.c index 6c4fc6338b26..8652c13f6ea2 100644 --- a/drivers/infiniband/core/uverbs_main.c +++ b/drivers/infiniband/core/uverbs_main.c @@ -669,6 +669,9 @@ static ssize_t ib_uverbs_write(struct file *filp, const char __user *buf, if ((hdr.in_words + ex_hdr.provider_in_words) * 8 != count) return -EINVAL; + if (ex_hdr.cmd_hdr_reserved) + return -EINVAL; + response = (char __user *)(unsigned long)ex_hdr.response; if (response) {