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=-16.6 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_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 5AEC1C43381 for ; Wed, 20 Mar 2019 14:54:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2041A2146E for ; Wed, 20 Mar 2019 14:54:54 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="DgQCTHAw" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728619AbfCTOyx (ORCPT ); Wed, 20 Mar 2019 10:54:53 -0400 Received: from mail-qt1-f202.google.com ([209.85.160.202]:43262 "EHLO mail-qt1-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728459AbfCTOwH (ORCPT ); Wed, 20 Mar 2019 10:52:07 -0400 Received: by mail-qt1-f202.google.com with SMTP id q21so2649457qtf.10 for ; Wed, 20 Mar 2019 07:52:06 -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=/AfMcWXUpr8qOV9jNlH+KOvJdLIB2O2rWZvj+eGhaHk=; b=DgQCTHAwsx9nOdP43FdX5LVEo87GnIfu0WmZk1NYabcIGCtKnsiekk4mOZRYJIhI1U rvCehvhBc06o8DcFgsseTvDqXb0bAW+gvKfeVD4L0KGfj2wOOOXK/fMnySAD9d5mCKCu 3Xy6ZFurPUHQ7qTNFw0+B5iut5R52YvqgYU/a0JEMSrKC9jRWo3AU420WBXrCWxeTOM5 YeoFqgkUOZ10TFamvrA+SuUuvAxE8e7foqYee5urs8q1dYqDp/xiKxBavemBAmX/sEHw DPuDEUNXQvvEZmE9YUfwESNhCqe00SvlS+lCubr0KgJlNbkXCmKhNkb8zOctNt9/cPVR Rukg== 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=/AfMcWXUpr8qOV9jNlH+KOvJdLIB2O2rWZvj+eGhaHk=; b=G6r/SCIVXR6TgG5qkw0PuNALpVOTnp7v6qrAnZMmL2nBePO/43YmyU3cFbUh/T2mEV 7PKNuPtsYlpZ36QzT/anw8C01YC/EP65R+tf/9rzYWTLAy66U74S445YqZsj37TtvjuA gFHAx47quDXX8Ie5DtHAEk97n3jJZl4ezIEWmpUOLzG+OxFvUWlwa3WPYSMI+dQ8hQVI A/fUPk+JvSQq7BjYK6eDq+8ZMg0hHFYGbQXdJTXZlr+YF5unaWUhKmTRU0by3UMOh8k1 HnW3uGtM8rzBNK49O85tlTFX3vSU5BFRxMNm6pDoL3ngh5qBLS7ImQDuaiIoPgaTK9bC 1vAw== X-Gm-Message-State: APjAAAUgQPvxIkUM+uLVd/JLHnYypn//PlQ17rxitqL5qYReUCUS5PoY e3PjDbzCo0Vdo9VQDsRr2D3FLxD/RoNJLIK1 X-Google-Smtp-Source: APXvYqy+ZGj1oA4MFc9JnMXadH7vhqJKC4uAMJ0YAN7IR5yuNOlRtTgk0L4VAoRYkahPatQ5yAXGf8UXWvJkE4CW X-Received: by 2002:ac8:38b7:: with SMTP id f52mr14823448qtc.7.1553093525814; Wed, 20 Mar 2019 07:52:05 -0700 (PDT) Date: Wed, 20 Mar 2019 15:51:21 +0100 In-Reply-To: Message-Id: <9f7d95da28b1fd5e601cbe43e81ee646e1ca6880.1553093421.git.andreyknvl@google.com> Mime-Version: 1.0 References: X-Mailer: git-send-email 2.21.0.225.g810b269d1ac-goog Subject: [PATCH v13 07/20] fs, arm64: untag user pointers in copy_mount_options From: Andrey Konovalov To: Catalin Marinas , Will Deacon , Mark Rutland , Robin Murphy , Kees Cook , Kate Stewart , Greg Kroah-Hartman , Andrew Morton , Ingo Molnar , "Kirill A . Shutemov" , Shuah Khan , Vincenzo Frascino , Eric Dumazet , "David S. Miller" , Alexei Starovoitov , Daniel Borkmann , Steven Rostedt , Ingo Molnar , Peter Zijlstra , Arnaldo Carvalho de Melo , Alex Deucher , "=?UTF-8?q?Christian=20K=C3=B6nig?=" , "David (ChunMing) Zhou" , Yishai Hadas , Mauro Carvalho Chehab , Jens Wiklander , Alex Williamson , linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, netdev@vger.kernel.org, bpf@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, linux-kernel@vger.kernel.org Cc: Dmitry Vyukov , Kostya Serebryany , Evgeniy Stepanov , Lee Smith , Ramana Radhakrishnan , Jacob Bramley , Ruben Ayrapetyan , Chintan Pandya , Luc Van Oostenryck , Dave Martin , Kevin Brodsky , Szabolcs Nagy , Andrey Konovalov 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 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. In copy_mount_options a user address is being subtracted from TASK_SIZE. If the address is lower than TASK_SIZE, the size is calculated to not allow the exact_copy_from_user() call to cross TASK_SIZE boundary. However if the address is tagged, then the size will be calculated incorrectly. Untag the address before subtracting. Signed-off-by: Andrey Konovalov --- fs/namespace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/namespace.c b/fs/namespace.c index c9cab307fa77..c27e5713bf04 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -2825,7 +2825,7 @@ void *copy_mount_options(const void __user * data) * the remainder of the page. */ /* copy_from_user cannot cross TASK_SIZE ! */ - size = TASK_SIZE - (unsigned long)data; + size = TASK_SIZE - (unsigned long)untagged_addr(data); if (size > PAGE_SIZE) size = PAGE_SIZE; -- 2.21.0.225.g810b269d1ac-goog