From patchwork Tue Apr 30 13:25:05 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrey Konovalov X-Patchwork-Id: 10923485 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id CE28914DB for ; Tue, 30 Apr 2019 13:25:49 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BE36926E3D for ; Tue, 30 Apr 2019 13:25:49 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id B1BE0285EB; Tue, 30 Apr 2019 13:25:49 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.5 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI, USER_IN_DEF_DKIM_WL autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6227126E3D for ; Tue, 30 Apr 2019 13:25:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728454AbfD3NZr (ORCPT ); Tue, 30 Apr 2019 09:25:47 -0400 Received: from mail-qt1-f202.google.com ([209.85.160.202]:40288 "EHLO mail-qt1-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727099AbfD3NZq (ORCPT ); Tue, 30 Apr 2019 09:25:46 -0400 Received: by mail-qt1-f202.google.com with SMTP id g28so13049120qtk.7 for ; Tue, 30 Apr 2019 06:25:45 -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=XhTfun6kQ0RRzRGxeYV1Lxl9M9fvGqRUvmzO5QW1/Iw=; b=wJdQ1UGK5yN+4uNr4h/B5QAZg4CL5PwyVx/Pw0wXlRL/1oGZsU8xxjXpZhWnko4SRI fd58gicIFCILzVPy4t7gpYBYkZYkBR3FmblDk49rQtqjc+3RWgZP2PESfhPKYuSabBw/ B0hXw+/teu1vbGfMkq/9KC8ilccnVzEvxDboYdIBbHp/DJQFCI0D5tDe+o/VISE54DyV St7L+ZfiWURBvKb49SaxC44tIWiHtqDmkV/TM32oplri8v6dnEdHN+6rXyhwe32Swezt x0OHZZDCsWZFgoiC74TFCi6OtAop9i/h8/+cUKSH3r+foqub7XosNX+XNvDEf+4uDkZz /4Vg== 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=XhTfun6kQ0RRzRGxeYV1Lxl9M9fvGqRUvmzO5QW1/Iw=; b=EGTre8O7cPXcW07j7rWP1Hv/UTB50x2ZEZY3UVkY34fOcj4QNl00fPHFmQ21sOrZMm T11mz9YK2P0npfVPEmDS3wBoJIYyDtRTdJE9s0hc76P79f73RrNK3aoxlKoX2SLDC2iR MXbQ+e2FufnGyyosVXzLk4kmkLVek4joZ0Sv5TYB4d6H0D9i603AZ5QYlbGBYDypZyRx V85R5EOWTFEzsNWaZ92lRfQqt78Ch+W92uq466pKwrh/PcAGe1V/CpdMpBT7J0hiHqA7 RCBfdb6zbRpQ/4ziGGme3bxL2U3waUayYPXj079HunfreZMecRkg2SyzrV1GxEwup5BI zcTQ== X-Gm-Message-State: APjAAAXpq1BJTM7Twc44X69xXB68ixhh6wl6+eLukC2mQ782jkYKAL90 6G5xHxsjiDzId9tj1tW1d/oHsoCWkMhdVxrF X-Google-Smtp-Source: APXvYqznoxmsWRf0TRsMetoUzYzE4dAnT0nzUuom4UB8P1UAcmj3+/tm6hiTUWLYkHc/SM6nPM/1vvtkZ4BWAaOU X-Received: by 2002:a37:b683:: with SMTP id g125mr147309qkf.249.1556630745179; Tue, 30 Apr 2019 06:25:45 -0700 (PDT) Date: Tue, 30 Apr 2019 15:25:05 +0200 In-Reply-To: Message-Id: Mime-Version: 1.0 References: X-Mailer: git-send-email 2.21.0.593.g511ec345e18-goog Subject: [PATCH v14 09/17] fs, arm64: untag user pointers in copy_mount_options 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 , Kuehling@google.com, Felix , Deucher@google.com, Alexander , Koenig@google.com, Christian , Mauro Carvalho Chehab , Jens Wiklander , Alex Williamson , Leon Romanovsky , Dmitry Vyukov , Kostya Serebryany , Evgeniy Stepanov , Lee Smith , Ramana Radhakrishnan , Jacob Bramley , Ruben Ayrapetyan , Robin Murphy , Chintan Pandya , Luc Van Oostenryck , Dave Martin , Kevin Brodsky , Szabolcs Nagy , Andrey Konovalov Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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;