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 B780FC10F14 for ; Sun, 6 Oct 2019 17:59:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8FADD20673 for ; Sun, 6 Oct 2019 17:59:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570384742; bh=tCk26d+T+swVc3fMXQW/oo8S60/G6LbT8f9nF49ey3U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=kzxaCB0PkvmkxMIAcSAm1w4mQWCfMA5EpSz4bHtLvgBHS2bCDPzeUTsdqJ8AbQY9v lE6fstXUxE8AYsH4PVfkIHHmu5tQYNAd2yhBb4ub35qvXK3vmQ3mKxj40FmqkPGpoj KIzdCLNJQIN9VPT4PsJhtP77XAB95FXFJuaLFAzo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729390AbfJFRbP (ORCPT ); Sun, 6 Oct 2019 13:31:15 -0400 Received: from mail.kernel.org ([198.145.29.99]:57394 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727473AbfJFRbN (ORCPT ); Sun, 6 Oct 2019 13:31:13 -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 7BE7D2133F; Sun, 6 Oct 2019 17:31:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570383073; bh=tCk26d+T+swVc3fMXQW/oo8S60/G6LbT8f9nF49ey3U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ABqGAh9n61vwPNYvV2mFuM2X6wEFGSrYixA6Kj6nLtyWjm0ViDTxd+CI8uS5xXlF/ YXQ1S8OCPlv6EnWbLUXr4TnhdX5IacQmpNuqbb/I1IZEw0Maw9h5zULMGYc6owAhbS 2Vc+P4O/H2c3IgvK8uqml0vLH3eSsEMqMrBXnTCg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alexandre Ghiti , Kees Cook , Paul Burton , Luis Chamberlain , Albert Ou , Alexander Viro , Catalin Marinas , Christoph Hellwig , Christoph Hellwig , James Hogan , Palmer Dabbelt , Ralf Baechle , Russell King , Will Deacon , Andrew Morton , Linus Torvalds , Sasha Levin Subject: [PATCH 4.19 075/106] mips: properly account for stack randomization and stack guard gap Date: Sun, 6 Oct 2019 19:21:21 +0200 Message-Id: <20191006171155.204874463@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191006171124.641144086@linuxfoundation.org> References: <20191006171124.641144086@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 b1f61b5bde3a1f50392c97b4c8513d1b8efb1cf2 ] 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/20190730055113.23635-10-alex@ghiti.fr Signed-off-by: Alexandre Ghiti Acked-by: Kees Cook Acked-by: Paul Burton 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: Ralf Baechle Cc: Russell King Cc: Will Deacon Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- arch/mips/mm/mmap.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/arch/mips/mm/mmap.c b/arch/mips/mm/mmap.c index 1b705fb2f10c4..233033f99d8fc 100644 --- a/arch/mips/mm/mmap.c +++ b/arch/mips/mm/mmap.c @@ -21,8 +21,9 @@ unsigned long shm_align_mask = PAGE_SIZE - 1; /* Sane caches */ EXPORT_SYMBOL(shm_align_mask); /* gap between mmap and stack */ -#define MIN_GAP (128*1024*1024UL) -#define MAX_GAP ((TASK_SIZE)/6*5) +#define MIN_GAP (128*1024*1024UL) +#define MAX_GAP ((TASK_SIZE)/6*5) +#define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) static int mmap_is_legacy(struct rlimit *rlim_stack) { @@ -38,6 +39,15 @@ 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