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=-9.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,T_DKIMWL_WL_HIGH,USER_AGENT_GIT 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 B655DC43219 for ; Thu, 2 May 2019 15:45:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7D078204EC for ; Thu, 2 May 2019 15:45:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556811928; bh=CKB00b82O/m91mqSznLKclqk4o1K3nQnzd/FY7DCOsw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=HX8UYwlh6okLUye/crFGx8he7vO0uVCPuE9EEU7vrKW2dXxHBYJvA/CLP7XUUfqAz e/WrbpgnMJHTkncq9TEBciH/MeFmQOhZjtci/bHZvvIV9MIRGvcuGg5egwegmQmwEF NffYpPQIsPhMp1FEZRagcbq2crRQJ10ZV9uxtb7s= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726560AbfEBPpU (ORCPT ); Thu, 2 May 2019 11:45:20 -0400 Received: from mail.kernel.org ([198.145.29.99]:42334 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727620AbfEBPZv (ORCPT ); Thu, 2 May 2019 11:25:51 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 72D7220449; Thu, 2 May 2019 15:25:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556810750; bh=CKB00b82O/m91mqSznLKclqk4o1K3nQnzd/FY7DCOsw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1jLmzMTyYPBKqScl0r3Z/LJtQZQPFU+bxaMmYM7C0QS8yNRfBNT9v9aHV7oGAF9i3 5Io2DCwIIYTf/Ef1Z04ivNQKT7M+YZtRZ/GBaiiA2NiCBBk/aVFSpUIohPeycIYnxF oxCIsc0uFIkxoBNO/QcYRbqmWwa6Bm4gb9z1977o= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Stefan Liebler , Martin Schwidefsky , "Sasha Levin (Microsoft)" Subject: [PATCH 4.19 08/72] s390: limit brk randomization to 32MB Date: Thu, 2 May 2019 17:20:30 +0200 Message-Id: <20190502143334.101925504@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190502143333.437607839@linuxfoundation.org> References: <20190502143333.437607839@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org [ Upstream commit cd479eccd2e057116d504852814402a1e68ead80 ] For a 64-bit process the randomization of the program break is quite large with 1GB. That is as big as the randomization of the anonymous mapping base, for a test case started with '/lib/ld64.so.1 ' it can happen that the heap is placed after the stack. To avoid this limit the program break randomization to 32MB for 64-bit and keep 8MB for 31-bit. Reported-by: Stefan Liebler Signed-off-by: Martin Schwidefsky Signed-off-by: Sasha Levin (Microsoft) --- arch/s390/include/asm/elf.h | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/arch/s390/include/asm/elf.h b/arch/s390/include/asm/elf.h index 7d22a474a040..f74639a05f0f 100644 --- a/arch/s390/include/asm/elf.h +++ b/arch/s390/include/asm/elf.h @@ -252,11 +252,14 @@ do { \ /* * Cache aliasing on the latest machines calls for a mapping granularity - * of 512KB. For 64-bit processes use a 512KB alignment and a randomization - * of up to 1GB. For 31-bit processes the virtual address space is limited, - * use no alignment and limit the randomization to 8MB. + * of 512KB for the anonymous mapping base. For 64-bit processes use a + * 512KB alignment and a randomization of up to 1GB. For 31-bit processes + * the virtual address space is limited, use no alignment and limit the + * randomization to 8MB. + * For the additional randomization of the program break use 32MB for + * 64-bit and 8MB for 31-bit. */ -#define BRK_RND_MASK (is_compat_task() ? 0x7ffUL : 0x3ffffUL) +#define BRK_RND_MASK (is_compat_task() ? 0x7ffUL : 0x1fffUL) #define MMAP_RND_MASK (is_compat_task() ? 0x7ffUL : 0x3ff80UL) #define MMAP_ALIGN_MASK (is_compat_task() ? 0 : 0x7fUL) #define STACK_RND_MASK MMAP_RND_MASK -- 2.19.1