From patchwork Fri Mar 15 19:51:30 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrey Konovalov X-Patchwork-Id: 1057218 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="vzUF5/hV"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 44Lbng588Lz9sBr for ; Sat, 16 Mar 2019 06:52:07 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727425AbfCOTwF (ORCPT ); Fri, 15 Mar 2019 15:52:05 -0400 Received: from mail-yw1-f73.google.com ([209.85.161.73]:35228 "EHLO mail-yw1-f73.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727371AbfCOTwE (ORCPT ); Fri, 15 Mar 2019 15:52:04 -0400 Received: by mail-yw1-f73.google.com with SMTP id d18so13189656ywb.2 for ; Fri, 15 Mar 2019 12:52:03 -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=z/lbJIk5a8zt10jywFDNy5ZdetbtZxhqc2S4ejPNJ3g=; b=vzUF5/hV3N6LymY3D+bJBpSatNRK6fXpwnZa/1KVNOg7xeGxEXTPkbw+wbEOfgpNDR np5G4rL7T1cd+Sz5iJ0RCOtU4P6bLZVS0l14Aq6zvISFR6mzBUWQWKFDoL13DmN3dbM+ SpIGClyUMZd9169+i8j5m3A6jrJ+Hyb10rwBPEQoaeyLAtm17DlPNuWH2RVG7xX1Y6TF 9LKSfozE1SWXebNzzat2ugJn18cSW7bw5YZG+7kazfWFB4UEOKlKg3watEf4bHP24M7o 9DP2o8Vqy0brwdDfGOvD+zN5V6FQV40T4Y8K+j9OS7OnApB4pexBW7Q518EArWyVitEY H6yw== 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=z/lbJIk5a8zt10jywFDNy5ZdetbtZxhqc2S4ejPNJ3g=; b=jdLEHSgGNZtjFS1I1Q3QDT+wM52gAkKgnAVu5g7j7zW6TNs6VY+C+tWqSBYffW2UmC QYfHwTcDNGLpezUa2iUApymSIr6rQrVC2AOMyvJPB3o512PxgH6ppDcbkhn60bDQxjuw g1XvukVLR5IDM9Swlh9h3QlwdIxr6vJD4cPgkHj4f846wLzA4wyajuuzJXPpwOtbxfWZ U9cgGECG+JJ6wKR3UiVKtwoQcNSFMb1msBzFuDOsO6IKVd8OYpva60LxTqc12ydY9f4O zf6p9EkX2Ul+X5SP8t1Bp0NKsqdkvINekAGybQEyo0T7OK//JHFbzz+PsrascuiG8UnG G8/w== X-Gm-Message-State: APjAAAXtus/R7pu6FJwTE6nKazMRzzCo3zbpIsNG0kA+NFElxxFFOOu5 seO4qbHGuAMVqqdckUAhaEWimNLrHVg2rBiF X-Google-Smtp-Source: APXvYqzi5LEkko6ByM4uqeA/ILUmpPQs4A8NqtI2/DdkNKEbP39lGUp9icnx2HlBixyjeGCue9FZGuIPU0jeuK+1 X-Received: by 2002:a81:8a46:: with SMTP id a67mr2389102ywg.26.1552679522975; Fri, 15 Mar 2019 12:52:02 -0700 (PDT) Date: Fri, 15 Mar 2019 20:51:30 +0100 In-Reply-To: Message-Id: Mime-Version: 1.0 References: X-Mailer: git-send-email 2.21.0.360.g471c308f928-goog Subject: [PATCH v11 06/14] 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;