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=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 EE44FC32793 for ; Sun, 29 Sep 2019 17:32:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BA5FE21928 for ; Sun, 29 Sep 2019 17:32:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569778350; bh=XYxWmfkrAOzZbg8dXacVi8SYdT7TPR48wH7ingN4Pwo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=YyV7LKdTN+YcFauwc/nCvHSwDl+9c0G1CPHc75wACSGZun2AxeJazp0TkOpcD5b1i ccZluqSuyYKprclxOcklxNreHteNejrKCVRWglZ0vN7rYePrkU4BqMGUqSCbn09PeW xAQDqFGXLMSCXNDc9cxI/WfcdVj3qfEeSVRjrD/E= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729779AbfI2Rc3 (ORCPT ); Sun, 29 Sep 2019 13:32:29 -0400 Received: from mail.kernel.org ([198.145.29.99]:43370 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729690AbfI2Rc2 (ORCPT ); Sun, 29 Sep 2019 13:32:28 -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 062CA2086A; Sun, 29 Sep 2019 17:32:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569778347; bh=XYxWmfkrAOzZbg8dXacVi8SYdT7TPR48wH7ingN4Pwo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=stMcrQs9xTR+FRzpue4BjWa2auSN7SQz2nxyB4yZ5ug880pVEk5COP2ULS0F7KL6K c4+DxqFonifIxj/AT0/EvCCcbto0dRysFzAiUbOnMC0ZiqIVIF9zijiy05eN0yZ1vf CiWZZJzNOOeOBoqwit+ZFHpYTzxJTtYrz3C27Q8M= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: 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 AUTOSEL 5.3 46/49] arm64: consider stack randomization for mmap base only when necessary Date: Sun, 29 Sep 2019 13:30:46 -0400 Message-Id: <20190929173053.8400-46-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190929173053.8400-1-sashal@kernel.org> References: <20190929173053.8400-1-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 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