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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,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 8F57EC0044C for ; Thu, 1 Nov 2018 23:06:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5081A20657 for ; Thu, 1 Nov 2018 23:06:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="SiujZf+1" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5081A20657 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org 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 S1728134AbeKBILj (ORCPT ); Fri, 2 Nov 2018 04:11:39 -0400 Received: from mail-lf1-f65.google.com ([209.85.167.65]:43684 "EHLO mail-lf1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726386AbeKBILj (ORCPT ); Fri, 2 Nov 2018 04:11:39 -0400 Received: by mail-lf1-f65.google.com with SMTP id u18so72490lff.10 for ; Thu, 01 Nov 2018 16:06:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=JK7AVYBL18PspaXDAhKnWR3redHMvvAm28q/cu6N5mc=; b=SiujZf+1Ptp1RlRhBVl7UAcrh0NLbUL1ELLokiHM0yUZsN3b3N0/XxSFG2OZwb2PiJ 7echAW10emwhK9iqLm/DIT5PZDSjWKmLY+Ih/drLvPAqAAc7vFYYBKbEtAdsi8D2obCJ BscHl2AzSxkKaELdP2hKG0MEaGTw8irpx8hcw= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=JK7AVYBL18PspaXDAhKnWR3redHMvvAm28q/cu6N5mc=; b=SS9nRmH0ArxrD660shhqt99EEs2zWMkTJEh039072SdhqpVJyJPgmMJO2KzIfElmPA a/lTVBLTpZTgGuBpQg3WpaHpziJwSsRTbso72sZTpuPWIrakwsyfReFaIFq6Ocu6AZ48 cuk9ZBU7hl/aoX8C+DlVlZDFrIz9vIrmODKAoTKklh3+Z1CHviCYQdySLc/bD44kzoJv QIOqgnKgrNzh50W7PAlHwbILOjQ8LYUgIfCkBduREVD7mGClch2buCEsyLbkiA5TPCEa Isx7QsIWRaJcJ2JVfXKGuA7ndymNUUlMTeMMItgLDBbD+yV0qg2udu0EZB/+I3DZBi8B wS5Q== X-Gm-Message-State: AGRZ1gJJKZZep4rSBS54OHt/W5wD5hU7Xp5SqPQahITGQkkdtj9Zd8Qm 8ffDVmn/fmY/dYcAk5z+c0O18mmvOeU= X-Google-Smtp-Source: AJdET5c/ke9jZ/Akmv4koVO5RRzW9UiMQgpyOa07MdPUi3X9pVD6htCM5j3ql0gfJMRFMe5w0E1hyg== X-Received: by 2002:a19:48d0:: with SMTP id v199mr5657292lfa.104.1541113597119; Thu, 01 Nov 2018 16:06:37 -0700 (PDT) Received: from mail-lj1-f173.google.com (mail-lj1-f173.google.com. [209.85.208.173]) by smtp.gmail.com with ESMTPSA id x29-v6sm3523468ljb.69.2018.11.01.16.06.36 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 01 Nov 2018 16:06:36 -0700 (PDT) Received: by mail-lj1-f173.google.com with SMTP id u6-v6so134215ljd.1 for ; Thu, 01 Nov 2018 16:06:36 -0700 (PDT) X-Received: by 2002:a2e:2416:: with SMTP id k22-v6mr217382ljk.80.1541113595783; Thu, 01 Nov 2018 16:06:35 -0700 (PDT) MIME-Version: 1.0 References: <20181101171938-mutt-send-email-mst@kernel.org> In-Reply-To: From: Linus Torvalds Date: Thu, 1 Nov 2018 16:06:19 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PULL] vhost: cleanups and fixes To: Kees Cook Cc: mst@redhat.com, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, Linux Kernel Mailing List , Andrew Morton , bijan.mottahedeh@oracle.com, gedwards@ddn.com, joe@perches.com, lenaic@lhuard.fr, liang.z.li@intel.com, mhocko@kernel.org, mhocko@suse.com, stefanha@redhat.com, wei.w.wang@intel.com Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Nov 1, 2018 at 4:00 PM Kees Cook wrote: > > + memset(&rsp, 0, sizeof(rsp)); > + rsp.response = VIRTIO_SCSI_S_FUNCTION_REJECTED; > + resp = vq->iov[out].iov_base; > + ret = __copy_to_user(resp, &rsp, sizeof(rsp)); > > Is it actually safe to trust that iov_base has passed an earlier > access_ok() check here? Why not just use copy_to_user() instead? Good point. We really should have removed those double-underscore things ages ago. Also, apart from the address, what about the size? Wouldn't it be better to use copy_to_iter() rather than implement it badly by hand? Linus