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=-17.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT, USER_IN_DEF_DKIM_WL 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 89999C76190 for ; Tue, 23 Jul 2019 17:59:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5E4C8218A0 for ; Tue, 23 Jul 2019 17:59:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="cRcOEH0i" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391262AbfGWR7e (ORCPT ); Tue, 23 Jul 2019 13:59:34 -0400 Received: from mail-qk1-f202.google.com ([209.85.222.202]:50574 "EHLO mail-qk1-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391334AbfGWR7d (ORCPT ); Tue, 23 Jul 2019 13:59:33 -0400 Received: by mail-qk1-f202.google.com with SMTP id e18so37034039qkl.17 for ; Tue, 23 Jul 2019 10:59:32 -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=mo6ZyD7PJiiiTnkBfnFT33xmRSSjLb2erTRpgEGb4jw=; b=cRcOEH0iv2407FEeEXiGtfbNaRtJQIzg5XbYICzGVGc43sPOA3+CZIMWAHKgebQ1Fd NhXvQ2XcNcF8R9x/znx8/B+ZWBuFc0pppCQj6IxF/91ZQehMjq/FUgtTO1kgaD+sdo+u g0fX97ge7Kl52ZUaa6b+4pEh6IxUyFSuMDNJlzhUpxY5RLeNi8LIb5QOqygzH5YcXwTw u/vwHZkzfH96V/r4aumfuyQXlNmESoQtl9/gLW/U3oOdnKUbG/Ywu4Xo6BgLwOzrtBVU Gf76BaPylfmhv0ijCpRq3ZN2WZ9BE8VMsOdxcjRzxf/93AljoTsAfpUOJtPXkeNJ+1FY hU+A== 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=mo6ZyD7PJiiiTnkBfnFT33xmRSSjLb2erTRpgEGb4jw=; b=i5po0zbN8qbvkd7TEWHAJVlnl5nda8OBuKgFBtc/WhNDYEOuYMPnCnN7aMxiNTNY1Z wW2mOVWUXvrYU6o8nWE11P3Ggb/DK1TZr0hdGrUKnKmzmw3LdEgBS2t2acXWKOu8y2cQ pkenygVrHsOzNQkx51pZGjPajhA6am5SPLLtiHpgF82+18zzBX/Qdq3WwxXsBsZKMawJ /c6WIh3Vnjk1fkBpdB5gnu8KTEcrKHBrF++IqzkrsQlJJ9D4xCzWxfDjCuqySxn73IuM 9CS0WCxzlsA6HvKsZ5nnOZ8enZHZowJcPN2B+JWht8srIUsjN2xEPZwzvXbWmUnrx7i6 bTMA== X-Gm-Message-State: APjAAAXDCSVApgHtdYgRRh69bcKMh7OLHEl1CQnalI0wjwkSYQEnYq6W JcYqt34/LlWOLA5No//Ezg6StWovcZ4eUHVb X-Google-Smtp-Source: APXvYqwqXUnbT9S2ecddRPfsS72rTxoBtLQXpIQx9JM0kIhhjvtv5eSOcsPLQ4y/4499Xb23XuIGaF+KOaOVjXRR X-Received: by 2002:a37:47d1:: with SMTP id u200mr49170508qka.21.1563904772061; Tue, 23 Jul 2019 10:59:32 -0700 (PDT) Date: Tue, 23 Jul 2019 19:58:45 +0200 In-Reply-To: Message-Id: Mime-Version: 1.0 References: X-Mailer: git-send-email 2.22.0.709.g102302147b-goog Subject: [PATCH v19 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 , Mike Rapoport Content-Type: text/plain; charset="UTF-8" Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org 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: Mike Rapoport Reviewed-by: Vincenzo Frascino Reviewed-by: Catalin Marinas Reviewed-by: Kees Cook Signed-off-by: Andrey Konovalov --- fs/userfaultfd.c | 22 ++++++++++++---------- 1 file changed, 12 insertions(+), 10 deletions(-) diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c index ccbdbd62f0d8..6284a4e719cb 100644 --- a/fs/userfaultfd.c +++ b/fs/userfaultfd.c @@ -1271,21 +1271,23 @@ 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; } @@ -1335,7 +1337,7 @@ 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; @@ -1524,7 +1526,7 @@ 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; @@ -1675,7 +1677,7 @@ 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; @@ -1715,7 +1717,7 @@ 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; /* @@ -1771,7 +1773,7 @@ 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; -- 2.22.0.709.g102302147b-goog