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=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,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 2D135C10F11 for ; Mon, 22 Apr 2019 19:56:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DAEBA204EC for ; Mon, 22 Apr 2019 19:56:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1555963008; bh=elSHBFb/NSOyzOxs1mg7pMfZIfNGVCUSZ3WgmPsx7YI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=xrqY3dNhFm60FKcVOEn+rv0f0y6qvtiU4iJiE0cuoz8H3rtX6wK9IcZTPY3Fohe7S AMT3LwX3sHH8hsRdvqK2lipZL3cWLyxriMfi5R0vG+CFcdNBm3rbyQ7L5uTJm4uaqg nQwqmTDWGlvOj1wpbmlX4kvpDHbt0hvZtXkXO2OM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731647AbfDVT4r (ORCPT ); Mon, 22 Apr 2019 15:56:47 -0400 Received: from mail.kernel.org ([198.145.29.99]:52424 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730659AbfDVTsw (ORCPT ); Mon, 22 Apr 2019 15:48:52 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C842521916; Mon, 22 Apr 2019 19:48:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1555962532; bh=elSHBFb/NSOyzOxs1mg7pMfZIfNGVCUSZ3WgmPsx7YI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NCe1Vctcz+kd0vMDiucr+QdrtrqJFYfTtp/TE2W+l4/nVE8YCjbDzT9gTbfzkN2AU wW97ZIXS9SEEvmMKhPMbGedx3xdpbfFwNKitCLH7WSJ95HiYrngppSVQRpsd40LArq YjLBHiLPwD8VN6XNIyPLIC5bzJBOwdB75m0C0X7E= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Martin Schwidefsky , Sasha Levin , linux-s390@vger.kernel.org Subject: [PATCH AUTOSEL 4.9 02/29] s390: limit brk randomization to 32MB Date: Mon, 22 Apr 2019 15:48:21 -0400 Message-Id: <20190422194848.13049-2-sashal@kernel.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190422194848.13049-1-sashal@kernel.org> References: <20190422194848.13049-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Martin Schwidefsky [ 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