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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 D8A94C4360C for ; Sun, 6 Oct 2019 17:53:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B0F6820673 for ; Sun, 6 Oct 2019 17:53:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570384387; bh=XYxWmfkrAOzZbg8dXacVi8SYdT7TPR48wH7ingN4Pwo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=1fiA6phBAyM0KVNqF0jlH8LmeoCyfRJK3J5fDfXiWtQV3SW8jFeuATfun2YV+Tta6 lLEKFINFmeUy5vCI49lLTU2ye6DrN5UlrnBzwWowRv05FyIkw7EqlJdgRZbSDaw5Cd ct7P9vxSTd81Ggo4xvu4hAY2C5i1VxKxOfIb2g+4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730599AbfJFRiY (ORCPT ); Sun, 6 Oct 2019 13:38:24 -0400 Received: from mail.kernel.org ([198.145.29.99]:37540 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730591AbfJFRiV (ORCPT ); Sun, 6 Oct 2019 13:38:21 -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 986B920700; Sun, 6 Oct 2019 17:38:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570383500; bh=XYxWmfkrAOzZbg8dXacVi8SYdT7TPR48wH7ingN4Pwo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=aexee1EBHtLpTUZFNh7YCSLRQNv/AloY8MyvgQaEjLHVBKRb0sopcNaa3Z1K6Wyq7 jLpOiMr7LkYwGWhb+bCSrHlv8sjmi2MnhtsZe9/IezhYTHDARn/YRjwzWqU7GeyeZ+ v4HTGhnGXLper1FarreB8ph2JqHvsUTCwv17EapY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alexandre Ghiti , Catalin Marinas , Kees Cook , Christoph Hellwig , Luis Chamberlain , Albert Ou , Alexander Viro , Christoph Hellwig , James Hogan , Palmer Dabbelt , Paul Burton , Ralf Baechle , Russell King , Will Deacon , Andrew Morton , Linus Torvalds , Sasha Levin Subject: [PATCH 5.2 125/137] arm64: consider stack randomization for mmap base only when necessary Date: Sun, 6 Oct 2019 19:21:49 +0200 Message-Id: <20191006171219.731258729@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191006171209.403038733@linuxfoundation.org> References: <20191006171209.403038733@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Alexandre Ghiti [ Upstream commit e8d54b62c55ab6201de6d195fc2c276294c1f6ae ] Do not offset mmap base address because of stack randomization if current task does not want randomization. Note that x86 already implements this behaviour. Link: http://lkml.kernel.org/r/20190730055113.23635-4-alex@ghiti.fr Signed-off-by: Alexandre Ghiti Acked-by: Catalin Marinas Acked-by: Kees Cook Reviewed-by: Christoph Hellwig Reviewed-by: Luis Chamberlain Cc: Albert Ou Cc: Alexander Viro Cc: Christoph Hellwig Cc: James Hogan Cc: Palmer Dabbelt Cc: Paul Burton Cc: Ralf Baechle Cc: Russell King Cc: Will Deacon Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- arch/arm64/mm/mmap.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/arch/arm64/mm/mmap.c b/arch/arm64/mm/mmap.c index b050641b51392..8dac7110f0cb5 100644 --- a/arch/arm64/mm/mmap.c +++ b/arch/arm64/mm/mmap.c @@ -54,7 +54,11 @@ unsigned long arch_mmap_rnd(void) static unsigned long mmap_base(unsigned long rnd, struct rlimit *rlim_stack) { unsigned long gap = rlim_stack->rlim_cur; - unsigned long pad = (STACK_RND_MASK << PAGE_SHIFT) + stack_guard_gap; + unsigned long pad = stack_guard_gap; + + /* Account for stack randomization if necessary */ + if (current->flags & PF_RANDOMIZE) + pad += (STACK_RND_MASK << PAGE_SHIFT); /* Values close to RLIM_INFINITY can overflow. */ if (gap + pad > gap) -- 2.20.1