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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 14EA9C43142 for ; Thu, 2 Aug 2018 14:02:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 898C1214AB for ; Thu, 2 Aug 2018 14:02:24 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 898C1214AB Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lxorguk.ukuu.org.uk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732524AbeHBPxn (ORCPT ); Thu, 2 Aug 2018 11:53:43 -0400 Received: from www.llwyncelyn.cymru ([82.70.14.225]:47280 "EHLO fuzix.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732255AbeHBPxm (ORCPT ); Thu, 2 Aug 2018 11:53:42 -0400 Received: from alans-desktop (82-70-14-226.dsl.in-addr.zen.co.uk [82.70.14.226]) by fuzix.org (8.15.2/8.15.2) with ESMTP id w72E210M021673; Thu, 2 Aug 2018 15:02:02 +0100 Date: Thu, 2 Aug 2018 15:02:01 +0100 From: Alan Cox To: Anton Vasilyev Cc: Greg Kroah-Hartman , Jiri Slaby , linux-kernel@vger.kernel.org, ldv-project@linuxtesting.org Subject: Re: [PATCH] tty: rocket: Fix possible buffer overwrite on register_PCI Message-ID: <20180802150201.316e3361@alans-desktop> In-Reply-To: <20180727133931.12701-1-vasilyev@ispras.ru> References: <20180727133931.12701-1-vasilyev@ispras.ru> Organization: Intel Corporation X-Mailer: Claws Mail 3.16.0 (GTK+ 2.24.32; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 27 Jul 2018 16:39:31 +0300 Anton Vasilyev wrote: > If number of isa and pci boards exceed NUM_BOARDS on the path > rp_init()->init_PCI()->register_PCI() then buffer overwrite occurs > in register_PCI() on assign rcktpt_io_addr[i]. > > The patch adds check on upper bound for index of registered > board in register_PCI. > > Found by Linux Driver Verification project (linuxtesting.org). > > Signed-off-by: Anton Vasilyev > --- > drivers/tty/rocket.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/tty/rocket.c b/drivers/tty/rocket.c > index bdd17d2aaafd..b121d8f8f3d7 100644 > --- a/drivers/tty/rocket.c > +++ b/drivers/tty/rocket.c > @@ -1881,7 +1881,7 @@ static __init int register_PCI(int i, struct pci_dev *dev) > ByteIO_t UPCIRingInd = 0; > > if (!dev || !pci_match_id(rocket_pci_ids, dev) || > - pci_enable_device(dev)) > + pci_enable_device(dev) || i >= NUM_BOARDS) > return 0; > > rcktpt_io_addr[i] = pci_resource_start(dev, 0); This is a real fix but you want to check i >= NUM_BOARDS before you enable the device Alan