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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 19BC4C4360C for ; Sun, 29 Sep 2019 17:34:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E9DDB21A4A for ; Sun, 29 Sep 2019 17:34:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569778461; bh=lDQ0vRak90qAKBGgcQOhzIF+hJtm9oHmlBRzBXpF70A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=O4xc6rM952tdVSDYp2hYSUCpngb3hoTq8DoVrVluMfNve+/cNl1AHDZNX0K23l+DI TOqV1tZDpx69RqmdXKIBDcoLCViHVPadmVbpWasV2+ijo7LyyVSj5JWHIisy/Vnthd WIuAamswn7hcJOj1l6D0z8GGSHpwANN12PWERL5Y= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730343AbfI2ReU (ORCPT ); Sun, 29 Sep 2019 13:34:20 -0400 Received: from mail.kernel.org ([198.145.29.99]:46004 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729532AbfI2ReQ (ORCPT ); Sun, 29 Sep 2019 13:34:16 -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 6A46021925; Sun, 29 Sep 2019 17:34:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569778456; bh=lDQ0vRak90qAKBGgcQOhzIF+hJtm9oHmlBRzBXpF70A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MwjldOPzHSEpnV35hwp8T10B6vtPK9NF6cy475BtZG4KB+MdWaOxROwOzFgqFxe0S BKGyGb1P4oyaEpmliAnilYc3t8QxEXbB/zaGZT1p/cPsurSf9SCrh8VhqGjZFs0KPK 1tJDbVk4tOrlqVoObc54Q39WPiNwvOc/u23yDaZk= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Alexandre Ghiti , Kees Cook , Luis Chamberlain , Albert Ou , Alexander Viro , Catalin Marinas , Christoph Hellwig , Christoph Hellwig , James Hogan , Palmer Dabbelt , Paul Burton , Ralf Baechle , Russell King , Will Deacon , Andrew Morton , Linus Torvalds , Sasha Levin Subject: [PATCH AUTOSEL 5.2 41/42] arm: properly account for stack randomization and stack guard gap Date: Sun, 29 Sep 2019 13:32:40 -0400 Message-Id: <20190929173244.8918-41-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190929173244.8918-1-sashal@kernel.org> References: <20190929173244.8918-1-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: Alexandre Ghiti [ Upstream commit af0f4297286f13a75edf93677b1fb2fc16c412a7 ] This commit takes care of stack randomization and stack guard gap when computing mmap base address and checks if the task asked for randomization. This fixes the problem uncovered and not fixed for arm here: https://lkml.kernel.org/r/20170622200033.25714-1-riel@redhat.com Link: http://lkml.kernel.org/r/20190730055113.23635-7-alex@ghiti.fr Signed-off-by: Alexandre Ghiti Acked-by: Kees Cook Reviewed-by: Luis Chamberlain Cc: Albert Ou Cc: Alexander Viro Cc: Catalin Marinas Cc: Christoph Hellwig 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/arm/mm/mmap.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/arch/arm/mm/mmap.c b/arch/arm/mm/mmap.c index f866870db749c..bff3d00bda5be 100644 --- a/arch/arm/mm/mmap.c +++ b/arch/arm/mm/mmap.c @@ -18,8 +18,9 @@ (((pgoff)<> (PAGE_SHIFT - 12)) static int mmap_is_legacy(struct rlimit *rlim_stack) { @@ -35,6 +36,15 @@ static int mmap_is_legacy(struct rlimit *rlim_stack) static unsigned long mmap_base(unsigned long rnd, struct rlimit *rlim_stack) { unsigned long gap = rlim_stack->rlim_cur; + 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) + gap += pad; if (gap < MIN_GAP) gap = MIN_GAP; -- 2.20.1