From patchwork Mon Jul 8 15:13:35 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 168664 Delivered-To: patch@linaro.org Received: by 2002:a92:4782:0:0:0:0:0 with SMTP id e2csp7302838ilk; Mon, 8 Jul 2019 08:23:14 -0700 (PDT) X-Google-Smtp-Source: APXvYqw8Yfv/5G+I1cmFTUS8NfgsQjxcj6L1UcdxMJRyhvq2xsPpsxIjkBc8FhmywNIer7zOZpWi X-Received: by 2002:a17:90a:350c:: with SMTP id q12mr26503632pjb.46.1562599394697; Mon, 08 Jul 2019 08:23:14 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1562599394; cv=none; d=google.com; s=arc-20160816; b=sKeR2jCm3rK130gmUd3NRzJIMFT7WZHm2eUZIRY7Qj8qTkMvGO6c90eLFmo3T0LUas 7XS9DCvJjnxIaeslBIDPHmS2mCN2mPTx1ag2akj3hGglyJBsK5NiguRtgap3ePhpIhLs 2WuXCuOc9+bFsP+TJ4uTbcx0qqUMN15x/Llvn9v6VkckZmmCwRiKPGTXrrUpCF5CFNAN JCb+dun+Qc8lTCRVXhbHhCLv02zmMxyYmz2+g1F0GjbHViFyQo+NmIKHJeh5wBzjXFFS 40nJvRt1M6uIPcwN59jodsBewIBgfsbCZIizysYxqZH0RKaBjB7MrF/aGa2L8naA0XR4 VtqA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:content-transfer-encoding:mime-version :user-agent:references:in-reply-to:message-id:date:subject:cc:to :from:dkim-signature; bh=EBGThibohalGDQx0JHUjvLSErbP6tzO0lJHuIrkqJAw=; b=fz44vel4Yvkdg979PlFE7h9BEs9/W2rB8PTW2tMZlbjNOtUZZh7X0X1xsnpo4GMrBE e8dd3bZIpAITdMX06P4TZn/zEELmfAwcjQwgHCLYyLU6NamHP8bOMuZt4bEpla+i/3Tl Ew4Pw+Msz4XBfXzL9GL13SqHX8oOSuOIoxhNXNB+b1T/54xMAoyhvi9jT4MglXc2gumB ZDGYQZ+wK/hV3bVqkzZziwZ9u0he8xOAsV+Jm5KaYEz/rbpwI9LROB4kvbGjMHfIWLuE JUei5II1fzC6uPHFTZ38Nka2zejfuTVpW8GVfY/rwReUNe7TPdB4JtcWPiV3OsukhvCj oQ+w== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=xojPNPSw; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id v11si18018074plo.223.2019.07.08.08.23.14; Mon, 08 Jul 2019 08:23:14 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=xojPNPSw; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388154AbfGHPXM (ORCPT + 30 others); Mon, 8 Jul 2019 11:23:12 -0400 Received: from mail.kernel.org ([198.145.29.99]:50044 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388134AbfGHPXJ (ORCPT ); Mon, 8 Jul 2019 11:23:09 -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 D958E204EC; Mon, 8 Jul 2019 15:23:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1562599388; bh=N+UVgD7OA5w7i4Zf1c+vj6sMbNBUCNtULkD6pkUw0ws=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xojPNPSwViqvhqS/AWJkLO6l7Lr3/qj1C5vtEDrBcm0LUp2pv9r0gLx5hhZQ/CmC5 GRFDeIvWk4MmIUKvfnHsO+g68cXaWvZ/iUP30NzP/7zg8EWaVG4Tzmup/IeOUSDPsd E6GXmehiLDzU/K1sSkzPBjyL+50s7tywWO143HPQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Catalin Marinas , Ard Biesheuvel , Will Deacon Subject: [PATCH 4.9 102/102] arm64: kaslr: keep modules inside module region when KASAN is enabled Date: Mon, 8 Jul 2019 17:13:35 +0200 Message-Id: <20190708150531.760421168@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190708150525.973820964@linuxfoundation.org> References: <20190708150525.973820964@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Ard Biesheuvel commit 6f496a555d93db7a11d4860b9220d904822f586a upstream. When KASLR and KASAN are both enabled, we keep the modules where they are, and randomize the placement of the kernel so it is within 2 GB of the module region. The reason for this is that putting modules in the vmalloc region (like we normally do when KASLR is enabled) is not possible in this case, given that the entire vmalloc region is already backed by KASAN zero shadow pages, and so allocating dedicated KASAN shadow space as required by loaded modules is not possible. The default module allocation window is set to [_etext - 128MB, _etext] in kaslr.c, which is appropriate for KASLR kernels booted without a seed or with 'nokaslr' on the command line. However, as it turns out, it is not quite correct for the KASAN case, since it still intersects the vmalloc region at the top, where attempts to allocate shadow pages will collide with the KASAN zero shadow pages, causing a WARN() and all kinds of other trouble. So cap the top end to MODULES_END explicitly when running with KASAN. Cc: # 4.9+ Acked-by: Catalin Marinas Tested-by: Catalin Marinas Signed-off-by: Ard Biesheuvel [will: backport to 4.9.y] Signed-off-by: Will Deacon Signed-off-by: Greg Kroah-Hartman --- arch/arm64/kernel/module.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) --- a/arch/arm64/kernel/module.c +++ b/arch/arm64/kernel/module.c @@ -33,10 +33,14 @@ void *module_alloc(unsigned long size) { void *p; + u64 module_alloc_end = module_alloc_base + MODULES_VSIZE; + + if (IS_ENABLED(CONFIG_KASAN)) + /* don't exceed the static module region - see below */ + module_alloc_end = MODULES_END; p = __vmalloc_node_range(size, MODULE_ALIGN, module_alloc_base, - module_alloc_base + MODULES_VSIZE, - GFP_KERNEL, PAGE_KERNEL_EXEC, 0, + module_alloc_end, GFP_KERNEL, PAGE_KERNEL_EXEC, 0, NUMA_NO_NODE, __builtin_return_address(0)); if (!p && IS_ENABLED(CONFIG_ARM64_MODULE_PLTS) &&