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=-7.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,T_DKIMWL_WL_HIGH 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 DD82BC468BE for ; Sat, 8 Jun 2019 04:03:47 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 91093208C0 for ; Sat, 8 Jun 2019 04:03:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="fLmt71ol" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 91093208C0 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=chromium.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 2B38E6B0278; Sat, 8 Jun 2019 00:03:47 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 263976B027C; Sat, 8 Jun 2019 00:03:47 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 12BB96B027D; Sat, 8 Jun 2019 00:03:47 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from mail-pf1-f197.google.com (mail-pf1-f197.google.com [209.85.210.197]) by kanga.kvack.org (Postfix) with ESMTP id CFB1E6B0278 for ; Sat, 8 Jun 2019 00:03:46 -0400 (EDT) Received: by mail-pf1-f197.google.com with SMTP id 5so2835578pff.11 for ; Fri, 07 Jun 2019 21:03:46 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:dkim-signature:date:from:to:cc:subject :message-id:references:mime-version:content-disposition:in-reply-to; bh=2OBpahu1EQjx5jm6yrfBCMrimRWI/S6HKVQllmyKwms=; b=ClD0VamdS7OHYgRh1JNp0uNDmxNZkBls6UA8eujFgUbdH55iSvBZcjdApd5p4CXb0j g9x52+OMCMjDgU03WUXi7ccswV5ituI79fkys4xBTB69cqiQ/jndoyQQW0V7UKVGJVXt Hq4loo3Zz+mOwO3UHnz+EIDl/nK0h1Mrw6A83XcWEdXN49eTa/KAAx0baQYBbby0+pZG QIXGq3g+SzEp3MuXPe2syVmlH3G/BwNlwUs2s9TVqDKN8di01YzK/VlwshVGUmUSxOf2 QR9nJpY7gUt/xc5MVGKMzIg3d9e/RlpYeHPnClOjq+vxK5dGnFpOvs9YniiAuPIDx/J+ BxmA== X-Gm-Message-State: APjAAAVQq1aBA2gkZ9asBEz7uZ4irAj+9p82g3S80jk9n5RJYhM0quhu w2T2mgMq1zCqFJ6i8oUPUq882wUsyOcedMXbEk2BQEdhnBD8h8H9p9+N9JFSI3RJMi1B80IeDV4 XSuzOdq1QLVR1bLWrFGn3civ7R9TEj4ETDduc7BO1nLEnegLOSvCEa8kxVYH1LdzbOw== X-Received: by 2002:a63:6ec6:: with SMTP id j189mr377154pgc.168.1559966626441; Fri, 07 Jun 2019 21:03:46 -0700 (PDT) X-Received: by 2002:a63:6ec6:: with SMTP id j189mr377109pgc.168.1559966625729; Fri, 07 Jun 2019 21:03:45 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1559966625; cv=none; d=google.com; s=arc-20160816; b=kUeIN6vyHHQV0h5vhaA8rCVIMTfVDBRm8uX+bYFG3uuZN1SiSBtWnCaIlKuNNT2dZu NOVBfUOAcHNlzeAyd1841j0HwH4Sa+UFRk3Zxgx/fFUQ8mp8DUsqx0dq7ce2D6ZiBBk8 NIuUTbY2Q0AwwcEBGulBpEAdXSybqN7K0hlG/NvFDPCQzl77hFSBDdH3QU27csnOLXML gi3pMDVu/u5hG5bYik/Q9/uov6/ngrU885DvEOiNLe5eZrW1Y7oq3HBVWRYc/VwRtKnc BTUCiVCiJMQYT9etYbC4gXgpg0+9YOYJ97GVQt5eWkhTErg2DwBrDRlp6NU8OB3I3StO xzNA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:dkim-signature; bh=2OBpahu1EQjx5jm6yrfBCMrimRWI/S6HKVQllmyKwms=; b=rLeqXkrNXqKqfwq0MGBja5+Rf5k/pICql5ijFH4VOVphbjRIlC2rSFjrOevV5C1sg7 IXy84TEvPtiKTAJhAh07B7qa+gecic8GR1lNOiYLximGSBm2houu6UYIh+FVbbx5anFI qRUJ/xYvfKol3rtCMoj0AmBFROCMXuRFeKfeb2XzSf6KID+3zipaZHV3UXQqsaI0FYFW Ikbwumu/pjNXbN36mlVHNKwTl8f0Vf3q2rxfXJqjVZUuifaxmQJLHRdhZCReEjOL5MmR dCUvgYG6Rf7inFIk4Lk3PiKoVlLgvrgvxjr5pemJZ4HrdKyDGyaprKIQbH0FCte9v7eP YLJg== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@chromium.org header.s=google header.b=fLmt71ol; spf=pass (google.com: domain of keescook@chromium.org designates 209.85.220.65 as permitted sender) smtp.mailfrom=keescook@chromium.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=chromium.org Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id t11sor3600094pgs.22.2019.06.07.21.03.45 for (Google Transport Security); Fri, 07 Jun 2019 21:03:45 -0700 (PDT) Received-SPF: pass (google.com: domain of keescook@chromium.org designates 209.85.220.65 as permitted sender) client-ip=209.85.220.65; Authentication-Results: mx.google.com; dkim=pass header.i=@chromium.org header.s=google header.b=fLmt71ol; spf=pass (google.com: domain of keescook@chromium.org designates 209.85.220.65 as permitted sender) smtp.mailfrom=keescook@chromium.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=chromium.org DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=2OBpahu1EQjx5jm6yrfBCMrimRWI/S6HKVQllmyKwms=; b=fLmt71olPLiQkxDGGLQPrvCgYkZj1mqoJ4PBg/f8Tk54bfcewYSZXr//1iYtcLODaG AZveCJmWVDOJ368vf6zoV+293mE/hykWvD1eLbEkiRUKR99tKynL4WvEtWLecnVqE/K5 NXI3dW3eaM1dHfIA1jf7g8U4v53Yd/wL4GPXA= X-Google-Smtp-Source: APXvYqyWrZDig2mXPzxoViG3lFlq1Wog/XberFCBwcpmN8vyxrNB4Pcdt7BQoh0EWedzEWISCi/OFA== X-Received: by 2002:a63:5a4b:: with SMTP id k11mr5562393pgm.143.1559966625274; Fri, 07 Jun 2019 21:03:45 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id m1sm3115007pjv.22.2019.06.07.21.03.43 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Fri, 07 Jun 2019 21:03:44 -0700 (PDT) Date: Fri, 7 Jun 2019 21:03:43 -0700 From: Kees Cook To: Andrey Konovalov Cc: linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-rdma@vger.kernel.org, linux-media@vger.kernel.org, kvm@vger.kernel.org, linux-kselftest@vger.kernel.org, Catalin Marinas , Vincenzo Frascino , Will Deacon , Mark Rutland , Andrew Morton , Greg Kroah-Hartman , Yishai Hadas , Felix Kuehling , Alexander Deucher , Christian Koenig , Mauro Carvalho Chehab , Jens Wiklander , Alex Williamson , Leon Romanovsky , Luc Van Oostenryck , Dave Martin , Khalid Aziz , enh , Jason Gunthorpe , Christoph Hellwig , Dmitry Vyukov , Kostya Serebryany , Evgeniy Stepanov , Lee Smith , Ramana Radhakrishnan , Jacob Bramley , Ruben Ayrapetyan , Robin Murphy , Kevin Brodsky , Szabolcs Nagy Subject: Re: [PATCH v16 09/16] fs, arm64: untag user pointers in fs/userfaultfd.c Message-ID: <201906072102.B58E6A609C@keescook> References: <7d6fef00d7daf647b5069101da8cf5a202da75b0.1559580831.git.andreyknvl@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <7d6fef00d7daf647b5069101da8cf5a202da75b0.1559580831.git.andreyknvl@google.com> X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Mon, Jun 03, 2019 at 06:55:11PM +0200, Andrey Konovalov wrote: > This patch is a part of a series that extends arm64 kernel ABI to allow to > pass tagged user pointers (with the top byte set to something else other > than 0x00) as syscall arguments. > > userfaultfd code use provided user pointers for vma lookups, which can > only by done with untagged pointers. > > Untag user pointers in validate_range(). > > Signed-off-by: Andrey Konovalov "userfaultfd: untag user pointers" Reviewed-by: Kees Cook -Kees > --- > fs/userfaultfd.c | 22 ++++++++++++---------- > 1 file changed, 12 insertions(+), 10 deletions(-) > > diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c > index 3b30301c90ec..24d68c3b5ee2 100644 > --- a/fs/userfaultfd.c > +++ b/fs/userfaultfd.c > @@ -1263,21 +1263,23 @@ static __always_inline void wake_userfault(struct userfaultfd_ctx *ctx, > } > > static __always_inline int validate_range(struct mm_struct *mm, > - __u64 start, __u64 len) > + __u64 *start, __u64 len) > { > __u64 task_size = mm->task_size; > > - if (start & ~PAGE_MASK) > + *start = untagged_addr(*start); > + > + if (*start & ~PAGE_MASK) > return -EINVAL; > if (len & ~PAGE_MASK) > return -EINVAL; > if (!len) > return -EINVAL; > - if (start < mmap_min_addr) > + if (*start < mmap_min_addr) > return -EINVAL; > - if (start >= task_size) > + if (*start >= task_size) > return -EINVAL; > - if (len > task_size - start) > + if (len > task_size - *start) > return -EINVAL; > return 0; > } > @@ -1327,7 +1329,7 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx, > goto out; > } > > - ret = validate_range(mm, uffdio_register.range.start, > + ret = validate_range(mm, &uffdio_register.range.start, > uffdio_register.range.len); > if (ret) > goto out; > @@ -1516,7 +1518,7 @@ static int userfaultfd_unregister(struct userfaultfd_ctx *ctx, > if (copy_from_user(&uffdio_unregister, buf, sizeof(uffdio_unregister))) > goto out; > > - ret = validate_range(mm, uffdio_unregister.start, > + ret = validate_range(mm, &uffdio_unregister.start, > uffdio_unregister.len); > if (ret) > goto out; > @@ -1667,7 +1669,7 @@ static int userfaultfd_wake(struct userfaultfd_ctx *ctx, > if (copy_from_user(&uffdio_wake, buf, sizeof(uffdio_wake))) > goto out; > > - ret = validate_range(ctx->mm, uffdio_wake.start, uffdio_wake.len); > + ret = validate_range(ctx->mm, &uffdio_wake.start, uffdio_wake.len); > if (ret) > goto out; > > @@ -1707,7 +1709,7 @@ static int userfaultfd_copy(struct userfaultfd_ctx *ctx, > sizeof(uffdio_copy)-sizeof(__s64))) > goto out; > > - ret = validate_range(ctx->mm, uffdio_copy.dst, uffdio_copy.len); > + ret = validate_range(ctx->mm, &uffdio_copy.dst, uffdio_copy.len); > if (ret) > goto out; > /* > @@ -1763,7 +1765,7 @@ static int userfaultfd_zeropage(struct userfaultfd_ctx *ctx, > sizeof(uffdio_zeropage)-sizeof(__s64))) > goto out; > > - ret = validate_range(ctx->mm, uffdio_zeropage.range.start, > + ret = validate_range(ctx->mm, &uffdio_zeropage.range.start, > uffdio_zeropage.range.len); > if (ret) > goto out; > -- > 2.22.0.rc1.311.g5d7573a151-goog > -- Kees Cook