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 1F4E0C4360F for ; Mon, 18 Mar 2019 17:18:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E1BD621741 for ; Mon, 18 Mar 2019 17:18:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="ZmesG1+v" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727944AbfCRRSL (ORCPT ); Mon, 18 Mar 2019 13:18:11 -0400 Received: from mail-qt1-f201.google.com ([209.85.160.201]:43691 "EHLO mail-qt1-f201.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727911AbfCRRSI (ORCPT ); Mon, 18 Mar 2019 13:18:08 -0400 Received: by mail-qt1-f201.google.com with SMTP id q21so5872282qtf.10 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=Aaz13aXaskMhA1xtdKlriHFLxuWjTyUZRfmkT6jEuDD1FLQXEcBOTQtcuvxLinTVuj r44hc4xrarFmE5rC4HAaJyQdypVxm8wrrhG+uEGvK1/x/DAfyuErH4mGtmF/cd0AfkAY RWz9gIOBikdUlbjc1t2g44+7kWv+ZTFDzM4eEiOY3xOfr3monynpJ4c3nuzaMW85PdW1 lkc+1zmSWUpHxbm89axQo54fIByLijjqCTn0UHBdJz3KUzhrXmVQ3www1JYUvJyvZYOA nhbabkWTNP/ExRlSLyR0x8D+ziD2CS7xoIOCYP/cQaYYfcRXcAykwtf5dyBWgfjOHTM7 FCVA== X-Gm-Message-State: APjAAAX13f2V7/FlD2Qho+73roo6JwgkN8ycy8QIz+RuqWmrP5SUjSQs QgYzge1f/0vu15Aw5eeW2pVYED4kyYgx/zJW 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 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