From patchwork Mon Jul 8 15:13:43 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: 168667 Delivered-To: patch@linaro.org Received: by 2002:a92:4782:0:0:0:0:0 with SMTP id e2csp7315058ilk; Mon, 8 Jul 2019 08:33:54 -0700 (PDT) X-Google-Smtp-Source: APXvYqwN10fUDNlqxcnpgEyoHKRh0ud14ne/fKLTOBnr/eMmhpJlPWE9S2BJ0vd2feFcFZOglbt8 X-Received: by 2002:a63:788a:: with SMTP id t132mr24945855pgc.332.1562600034457; Mon, 08 Jul 2019 08:33:54 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1562600034; cv=none; d=google.com; s=arc-20160816; b=mQ7MYyCHbRsJfOwBz2rgSVd7T7Bu4Qs5CspWn3mX059kQdy86eNNg36o6yOWZnI0Aa Gqqcfb++3rSqFvGWiFTNOT+zPCBfucB78NGfvmWnOWUkXWyZcqPFkJypyPmEIaEZp3KX udYhc3ptCVm+GE0uOlx9fkWpQiMl4jc831t/uuqpoTeCKPkz4nkKm3Phw/35ih3pKcaD 0A7IF+bvzOin9P7OPg25TKzxK/M2GYz367Iun9dxqJgJB0H3K4vPQdHusfInJW//nuEk JTB4ZkyLpyssP62SC8OInCNFX3lm0sIxkyST339wJdwRrRYSfQ4WsM/KhJ5vsnuKh8VB Jbpw== 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=Q0Bn/kCsAAEIsl7/JRuTgs73rspEWlcATaIwKGAvCAc=; b=n3XIrsutsrssHGZK8pw4pXmcmQQNDff1JsfeSFCE1YDzuKwQzH2M+qiuoy3zPii2ag pIRCwIkb9DFUgFg/rPhtUyuXHAvNzGqzfPP6L8Blu5laS+JO/stjOSehZq32ZOGJyg/l uzHks6DptxuZx6YOJmEfAqz3hTuA45+620sVVEFanxzDWyAtj6wrH6Xf4KtTf7SnRh1q Co5rMK7P0sXlA+HnDMxVITTXjjxSREnmqv3JeBOnWMnme+EGMezR9vh3shdIOW2ukGTt kyETXsrs5c2VAJdeEt9jk2xBEcYOkr18EaE8xRKjtC5NvzRdAGsKoSHme/VEwGTzBU7a v9SQ== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=d2N5ux5t; spf=pass (google.com: best guess record for domain of stable-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=stable-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 a5si17348676pjv.80.2019.07.08.08.33.54; Mon, 08 Jul 2019 08:33:54 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of stable-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=d2N5ux5t; spf=pass (google.com: best guess record for domain of stable-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=stable-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390450AbfGHPdx (ORCPT + 14 others); Mon, 8 Jul 2019 11:33:53 -0400 Received: from mail.kernel.org ([198.145.29.99]:36042 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390445AbfGHPdv (ORCPT ); Mon, 8 Jul 2019 11:33:51 -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 7BF1A204EC; Mon, 8 Jul 2019 15:33:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1562600031; bh=+LiCpwHsjJSrbJyVIAOZQxJz3K+eHJCNVBkQ9T3ckGk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=d2N5ux5tl/IkTXD2oXWDwkoXjch0hPjQ11AVCtE9ge+jB4PUthKoJbRZ1M+i0Tj6J Wk51etbcjE1wDOliudRVVF2PVVSOCnyHcRKrCuULUhwzY9XjzXPp2PcNX1ZyGvAT9G agxZeWRRY5hhYzDvet1XNoDXvBc6K5UdBgSVYzgE= 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 5.1 71/96] arm64: kaslr: keep modules inside module region when KASAN is enabled Date: Mon, 8 Jul 2019 17:13:43 +0200 Message-Id: <20190708150530.287560004@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190708150526.234572443@linuxfoundation.org> References: <20190708150526.234572443@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@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 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 @@ -32,6 +32,7 @@ void *module_alloc(unsigned long size) { + u64 module_alloc_end = module_alloc_base + MODULES_VSIZE; gfp_t gfp_mask = GFP_KERNEL; void *p; @@ -39,9 +40,12 @@ void *module_alloc(unsigned long size) if (IS_ENABLED(CONFIG_ARM64_MODULE_PLTS)) gfp_mask |= __GFP_NOWARN; + 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_mask, PAGE_KERNEL_EXEC, 0, + module_alloc_end, gfp_mask, PAGE_KERNEL_EXEC, 0, NUMA_NO_NODE, __builtin_return_address(0)); if (!p && IS_ENABLED(CONFIG_ARM64_MODULE_PLTS) &&