From patchwork Thu Dec 13 13:57:35 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Herton Ronaldo Krzesinski X-Patchwork-Id: 205948 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from chlorine.canonical.com (chlorine.canonical.com [91.189.94.204]) by ozlabs.org (Postfix) with ESMTP id DDE2C2C00A6 for ; Fri, 14 Dec 2012 01:08:41 +1100 (EST) Received: from localhost ([127.0.0.1] helo=chlorine.canonical.com) by chlorine.canonical.com with esmtp (Exim 4.71) (envelope-from ) id 1Tj9SL-0003n7-Vc; Thu, 13 Dec 2012 14:08:10 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by chlorine.canonical.com with esmtp (Exim 4.71) (envelope-from ) id 1Tj9QW-0002iE-EE for kernel-team@lists.ubuntu.com; Thu, 13 Dec 2012 14:06:16 +0000 Received: from 200.139.123.215.dynamic.adsl.gvt.net.br ([200.139.123.215] helo=canonical.com) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1Tj9QV-0004NN-OA; Thu, 13 Dec 2012 14:06:16 +0000 From: Herton Ronaldo Krzesinski To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Subject: [PATCH 090/241] s390/gup: add missing TASK_SIZE check to get_user_pages_fast() Date: Thu, 13 Dec 2012 11:57:35 -0200 Message-Id: <1355407206-17100-91-git-send-email-herton.krzesinski@canonical.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1355407206-17100-1-git-send-email-herton.krzesinski@canonical.com> References: <1355407206-17100-1-git-send-email-herton.krzesinski@canonical.com> Cc: Martin Schwidefsky , Heiko Carstens X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.13 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: kernel-team-bounces@lists.ubuntu.com Errors-To: kernel-team-bounces@lists.ubuntu.com 3.5.7.2 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Heiko Carstens commit d55c4c613fc4d4ad2ba0fc6fa2b57176d420f7e4 upstream. When walking page tables we need to make sure that everything is within bounds of the ASCE limit of the task's address space. Otherwise we might calculate e.g. a pud pointer which is not within a pud and dereference it. So check against TASK_SIZE (which is the ASCE limit) before walking page tables. Reviewed-by: Gerald Schaefer Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky Signed-off-by: Herton Ronaldo Krzesinski --- arch/s390/mm/gup.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/s390/mm/gup.c b/arch/s390/mm/gup.c index 65cb06e..4ccf9f5 100644 --- a/arch/s390/mm/gup.c +++ b/arch/s390/mm/gup.c @@ -183,7 +183,7 @@ int get_user_pages_fast(unsigned long start, int nr_pages, int write, addr = start; len = (unsigned long) nr_pages << PAGE_SHIFT; end = start + len; - if (end < start) + if ((end < start) || (end > TASK_SIZE)) goto slow_irqon; /*