From patchwork Mon Jun 24 14:32:53 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrey Konovalov X-Patchwork-Id: 11013363 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 6CF301580 for ; Mon, 24 Jun 2019 14:33:37 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5E2C428747 for ; Mon, 24 Jun 2019 14:33:37 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 5BA3F28BF7; Mon, 24 Jun 2019 14:33:37 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.5 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI, USER_IN_DEF_DKIM_WL autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D30BF28BDC for ; Mon, 24 Jun 2019 14:33:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729346AbfFXOdf (ORCPT ); Mon, 24 Jun 2019 10:33:35 -0400 Received: from mail-qt1-f202.google.com ([209.85.160.202]:34973 "EHLO mail-qt1-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729301AbfFXOde (ORCPT ); Mon, 24 Jun 2019 10:33:34 -0400 Received: by mail-qt1-f202.google.com with SMTP id v58so17262800qta.2 for ; Mon, 24 Jun 2019 07:33:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=xV4GbhfwTJs/VHD3XxRc3myky/6/dZivHKwnC5uKFNY=; b=VLugRRxW8NzEgheS31MNVa1Sf0NPG55w1n45MRa1PCRLK9hq7S2jBGoYLnFMFiHI5i hpX0xoMfsikUNRg8wsT/s7FiLojNQJbMZrLaUF3hUbhIT0quzLCgUnw+iuzryEs61l+O Ve0OmRPuLrSa3geOriI62VfPQqKbergnVirL4Oq9bZbq3yOHL4EORN4ukQhnIooC4ZN9 PZ1lLy0eIBkrTz3zU6usqrjjK7ENTukF79xqMm8AaDpm29IyoVXUdy6JraPyjXn+72vp F+QX4V4XVS+gqXq9OgmVKgBE0AfC5B+46IUnSBLokKMZbLpJOxTVnXtB640hiGZTFThT nCTg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=xV4GbhfwTJs/VHD3XxRc3myky/6/dZivHKwnC5uKFNY=; b=cWsYIm09C0NC3Fr7HhFr7J+cvaMm6CrNOZBGquWXe3NCOUJ5i/a8ZUidXmUtabh2JL BVPgjXl8/3Grue5AnY3y5T6CYKIPuH0VhaGNhbSiqKSqEtOFMas91BVLRRm3JDaNzyhE Cu43nHvGdcc9G9bKKkB9UpracY2Qw71ZM259gLsfvBP3PbDb0+uQvMXBtlBOL/uMg2bW GKqZlv2G84hf2sbYNTQO2i8d5p7lXWehb3EWo1g7iztFZ2TpfIcTwuQ5Wdtc+9DDBIDx Qv/L1kw+hnuWjCaHzYXgpLddm9MllmlhOiMYKUPN7n7VL6epnTCC0Juxw7ZVqqNdmhG0 kW9w== X-Gm-Message-State: APjAAAWNejh7RdmqqzOtwTVqFKSkmWEpID7/ljcaUjX7SjeDdvLbCsWU BwF6Aqp4rSb6PHoQ7+xvddl/IbGBSVh/8w3J X-Google-Smtp-Source: APXvYqwe8X+4yuXQ7UlZtRYriaSj9tE/sKjuV5CxgHmn3yQIPlD9lif2nlCyzd6rbdataPXUKZA07t9k3oZM6sHi X-Received: by 2002:a37:640f:: with SMTP id y15mr50777872qkb.79.1561386811824; Mon, 24 Jun 2019 07:33:31 -0700 (PDT) Date: Mon, 24 Jun 2019 16:32:53 +0200 In-Reply-To: Message-Id: Mime-Version: 1.0 References: X-Mailer: git-send-email 2.22.0.410.gd8fdbe21b5-goog Subject: [PATCH v18 08/15] userfaultfd: untag user pointers From: Andrey Konovalov To: 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 Cc: Catalin Marinas , Vincenzo Frascino , Will Deacon , Mark Rutland , Andrew Morton , Greg Kroah-Hartman , Kees Cook , 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 , Andrey Konovalov Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This patch is a part of a series that extends 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(). Reviewed-by: Vincenzo Frascino Reviewed-by: Catalin Marinas Reviewed-by: Kees Cook Signed-off-by: Andrey Konovalov Reviewed-by: Mike Rapoport --- fs/userfaultfd.c | 22 ++++++++++++---------- 1 file changed, 12 insertions(+), 10 deletions(-) diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c index ae0b8b5f69e6..c2be36a168ca 100644 --- a/fs/userfaultfd.c +++ b/fs/userfaultfd.c @@ -1261,21 +1261,23 @@ 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; } @@ -1325,7 +1327,7 @@ 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; @@ -1514,7 +1516,7 @@ 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; @@ -1665,7 +1667,7 @@ 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; @@ -1705,7 +1707,7 @@ 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; /* @@ -1761,7 +1763,7 @@ 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;