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=-8.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 9D592C433E0 for ; Thu, 4 Jun 2020 16:37:26 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 2881F2072E for ; Thu, 4 Jun 2020 16:37:26 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="ESnq7K1d" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2881F2072E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:53682 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jgsrt-00020i-9u for qemu-devel@archiver.kernel.org; Thu, 04 Jun 2020 12:37:25 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:53410) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jgsrJ-0001a1-Te for qemu-devel@nongnu.org; Thu, 04 Jun 2020 12:36:49 -0400 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:54870 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1jgsrJ-0001Do-1U for qemu-devel@nongnu.org; Thu, 04 Jun 2020 12:36:49 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1591288607; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=9727UxvqVmZxBE8Lz+WCTTNUT+mtnHrjU8BZCFTt+0o=; b=ESnq7K1dl6xiRqMAa+sW98OXhGNZHhdD3bDrQW5CaNMlcTg0SIVVJyUnszjysQow6QBLpX N4E900H+s0s22RH7tDC+hbVZy7Z0yjgdwNZl5llC6u4Q9Nu3fgDPjqJQTxsYoDnpwNZLfE SraboJvRdcNmAg82N4AkWnqQrcqho6k= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-456-18x4LPqpNeWbL6L-SGagpQ-1; Thu, 04 Jun 2020 12:36:43 -0400 X-MC-Unique: 18x4LPqpNeWbL6L-SGagpQ-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 53D8D1005510; Thu, 4 Jun 2020 16:36:42 +0000 (UTC) Received: from work-vm (ovpn-114-247.ams2.redhat.com [10.36.114.247]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 9D1902DE70; Thu, 4 Jun 2020 16:36:33 +0000 (UTC) Date: Thu, 4 Jun 2020 17:36:31 +0100 From: "Dr. David Alan Gilbert" To: P J P Subject: Re: [PATCH] pci: assert configuration access is within bounds Message-ID: <20200604163631.GB2890@work-vm> References: <20200604113525.58898-1-ppandit@redhat.com> MIME-Version: 1.0 In-Reply-To: <20200604113525.58898-1-ppandit@redhat.com> User-Agent: Mutt/1.13.4 (2020-02-15) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Content-Disposition: inline Received-SPF: pass client-ip=205.139.110.120; envelope-from=dgilbert@redhat.com; helo=us-smtp-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/06/04 12:22:43 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_PASS=-0.001, T_HK_NAME_DR=0.01, URIBL_BLOCKED=0.001 autolearn=_AUTOLEARN X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Peter Maydell , Daniel P =?iso-8859-1?Q?=2E_Berrang=E9?= , Prasad J Pandit , "Michael S . Tsirkin" , QEMU Developers , Gerd Hoffmann , Philippe =?iso-8859-1?Q?Mathieu-Daud=E9?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" * P J P (ppandit@redhat.com) wrote: > From: Prasad J Pandit > > While accessing PCI configuration bytes, assert that > 'address + len' is within PCI configuration space. > > Generally it is within bounds. This is more of a defensive > assert, in case a buggy device was to send 'address' which > may go out of bounds. Can a guest trigger this assert? Dave > Suggested-by: Philippe Mathieu-Daudé > Signed-off-by: Prasad J Pandit > --- > hw/pci/pci.c | 4 ++++ > 1 file changed, 4 insertions(+) > > Update v1: defensive assert as separate patch > -> https://lists.gnu.org/archive/html/qemu-devel/2020-06/msg00957.html > -> https://lists.gnu.org/archive/html/qemu-devel/2020-06/msg00960.html > > diff --git a/hw/pci/pci.c b/hw/pci/pci.c > index 70c66965f5..7bf2ae6d92 100644 > --- a/hw/pci/pci.c > +++ b/hw/pci/pci.c > @@ -1381,6 +1381,8 @@ uint32_t pci_default_read_config(PCIDevice *d, > { > uint32_t val = 0; > > + assert(address + len <= pci_config_size(d)); > + > if (pci_is_express_downstream_port(d) && > ranges_overlap(address, len, d->exp.exp_cap + PCI_EXP_LNKSTA, 2)) { > pcie_sync_bridge_lnk(d); > @@ -1394,6 +1396,8 @@ void pci_default_write_config(PCIDevice *d, uint32_t addr, uint32_t val_in, int > int i, was_irq_disabled = pci_irq_disabled(d); > uint32_t val = val_in; > > + assert(addr + l <= pci_config_size(d)); > + > for (i = 0; i < l; val >>= 8, ++i) { > uint8_t wmask = d->wmask[addr + i]; > uint8_t w1cmask = d->w1cmask[addr + i]; > -- > 2.26.2 > > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK