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 B8760C43219 for ; Thu, 2 May 2019 15:50:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8901D204EC for ; Thu, 2 May 2019 15:50:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556812214; bh=mCAzXQYMfAxlLqu0U3V4Avl84lWfKttGlE1GuRFcAKE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Tg2GTYetqgG12//fuLqYoCal1GisGeZuOODy96FBDZ830G4C1VC7/0Is3VZa+p2Ue Fzi6PtdUDB4Czyvh7FEXChUF22kyZ4bdhzXPMG63CbMEdo0tHNnft25CHgXkYWlFt9 eprYYzrBKlSsJhwFaL7FWdHJFx7BLZ9mvIjzAbFI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726451AbfEBPWH (ORCPT ); Thu, 2 May 2019 11:22:07 -0400 Received: from mail.kernel.org ([198.145.29.99]:37284 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726406AbfEBPWF (ORCPT ); Thu, 2 May 2019 11:22:05 -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 862152081C; Thu, 2 May 2019 15:22:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556810525; bh=mCAzXQYMfAxlLqu0U3V4Avl84lWfKttGlE1GuRFcAKE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eLwZmErPi8pgqFlo1nlPNeRnAvugtnfBJdVdpywvJssDufV8+ognZbzx2aRxVtqp8 lKBNrrb22jduZ6jN7YJdhXU6yNipgJaJ6AIqK+sz/Jdpj9ehShOm2VnF27JTgAHbJs pNFqdjW9iCBV5edgUsC3EOpyYEmRC8G+U8sGjGyw= 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 4.9 05/32] s390: limit brk randomization to 32MB Date: Thu, 2 May 2019 17:20:51 +0200 Message-Id: <20190502143317.201689230@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190502143314.649935114@linuxfoundation.org> References: <20190502143314.649935114@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 8d665f1b29f8..f0fe566a9910 100644 --- a/arch/s390/include/asm/elf.h +++ b/arch/s390/include/asm/elf.h @@ -215,11 +215,14 @@ 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