From patchwork Mon Mar 18 17:17:38 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrey Konovalov X-Patchwork-Id: 1057958 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=google.com header.i=@google.com header.b="ZmesG1+v"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 44NNDh3Xd4z9s71 for ; Tue, 19 Mar 2019 04:18:12 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727929AbfCRRSK (ORCPT ); Mon, 18 Mar 2019 13:18:10 -0400 Received: from mail-qt1-f202.google.com ([209.85.160.202]:36279 "EHLO mail-qt1-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727870AbfCRRSI (ORCPT ); Mon, 18 Mar 2019 13:18:08 -0400 Received: by mail-qt1-f202.google.com with SMTP id q12so14040532qtr.3 for ; Mon, 18 Mar 2019 10:18:07 -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=ZmesG1+vdfvVJVysloZ/DvNyAHwl1NeoVDeZqmznyOpJWfePQRGjlMOaVKfDpQrgzs J2EQbjkMYChUC5zNqacIMsL4hIDlSJ8LlP4Fmv1sBUKWq1gONhy9n6WlIdgh6miGrDT+ kxO+pObNRxAVLj1qO6umMp4FBt4KoE0pcjnUi2zV7lJYuNIAUHoun/OybTmy1PNaA5yQ p3eG+Dhv94MxYowpcID5/Yi84v5cik+7L0zhfsc+N+0vCh3BkkQf0oPyRfu2qOWqEfLW 2tCSF4/OHp/EYgkB0s7TOad99Oui2rlmLjv/5KNArBSNE7FFiFH/+uNURIDaDJj0/jzV BjkQ== 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=rci3KtdvODqTO8wLOse7Cpzt/pq9r4RPWEWQ+1u+DDQeTu1nNbM0naCvwHqeLyWG2L LHPmz1cpl4znQE8MXgXryyWQcb5AgW4kzUD6UM1ieazRAUM4uQSYRU0IGHsfuQ+1hEJS mvsYV/Dt+FkpsU24Q/E71CArHqDOkFQ4OqZLPgeywInO/TIEPjRulW247jDu6yYm+c1z 467t15Of9u6M04l4Z4xoC+wACXN9O/iuTbbmjm8mSgydAdq+1L3k1KMJxxY/pjlGJ2sz dRAOp1T61xiNJ4DKjoNUZ05vlKc//lWKZna6/YY8JaoLeSjqChE3OgOJOJESk0pr2v8q mpvA== X-Gm-Message-State: APjAAAXYXAU+EX9H4M6KpQ2xxLwr4UuJ0pmRpUTFqX/GzORN/glaEqOK XB5KNtqtZ45YNN90qGPeDxvcGy5QnkBztQQZ X-Google-Smtp-Source: APXvYqzQcEeEWS2cRarzaICPGg9P+n5KYCEBV6zZ1LX2+H91hhlcnbntbKdJigMJk6uOOiOh4IgPE1iT+lDz1l6o X-Received: by 2002:ac8:2733:: with SMTP id g48mr11081110qtg.0.1552929487390; Mon, 18 Mar 2019 10:18:07 -0700 (PDT) Date: Mon, 18 Mar 2019 18:17:38 +0100 In-Reply-To: Message-Id: Mime-Version: 1.0 References: X-Mailer: git-send-email 2.21.0.225.g810b269d1ac-goog Subject: [PATCH v12 06/13] 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 , linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, netdev@vger.kernel.org, bpf@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 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@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;