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=-6.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 5387CC282CB for ; Mon, 4 Feb 2019 10:48:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 15FEA2070C for ; Mon, 4 Feb 2019 10:48:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1549277328; bh=ZlEdznJGZI5dDuiNAC6ZviUs4L5niiaj4d+Nh3gCYMo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=0U8XXi7BGkD747deeueNqqdD4IQXf6eQMLEprMYKrDrqaPrYLF0pmHimKTS5Q013D 7mj7erBGXUBYIQmWuRQ3TMrDA/PybyZeZUWrqkrs4HwRRxtwwqNQ9OfQNsmk/4jtAk aDr3Xqdd77say7iUarZK7a8/ej6RYspSt1n0wXKM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731901AbfBDKsq (ORCPT ); Mon, 4 Feb 2019 05:48:46 -0500 Received: from mail.kernel.org ([198.145.29.99]:46692 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731411AbfBDKso (ORCPT ); Mon, 4 Feb 2019 05:48:44 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.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 35E8E2070C; Mon, 4 Feb 2019 10:48:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1549277323; bh=ZlEdznJGZI5dDuiNAC6ZviUs4L5niiaj4d+Nh3gCYMo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UsavTiKCegMpwh4R2gVFrxKSda0T0HSJPxfiBl6sjCdZ5sybIDzgkR1TKvriernmL m6hW+fqyV0emJwCPbXmzqJWsJMRPVmSG+xfRnOAgMuy45Lk1GE96vooZRksGbmJGv9 1YUbAaPMsBJj/tjl1H8W6Z7sV/tXZu+gnoYO/7NI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ard Biesheuvel , Will Deacon Subject: [PATCH 4.19 41/74] arm64: kaslr: ensure randomized quantities are clean also when kaslr is off Date: Mon, 4 Feb 2019 11:36:54 +0100 Message-Id: <20190204103624.801024564@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190204103619.714714157@linuxfoundation.org> References: <20190204103619.714714157@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore 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 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ard Biesheuvel commit 8ea235932314311f15ea6cf65c1393ed7e31af70 upstream. Commit 1598ecda7b23 ("arm64: kaslr: ensure randomized quantities are clean to the PoC") added cache maintenance to ensure that global variables set by the kaslr init routine are not wiped clean due to cache invalidation occurring during the second round of page table creation. However, if kaslr_early_init() exits early with no randomization being applied (either due to the lack of a seed, or because the user has disabled kaslr explicitly), no cache maintenance is performed, leading to the same issue we attempted to fix earlier, as far as the module_alloc_base variable is concerned. Note that module_alloc_base cannot be initialized statically, because that would cause it to be subject to a R_AARCH64_RELATIVE relocation, causing it to be overwritten by the second round of KASLR relocation processing. Fixes: f80fb3a3d508 ("arm64: add support for kernel ASLR") Cc: # v4.6+ Signed-off-by: Ard Biesheuvel Signed-off-by: Will Deacon Signed-off-by: Greg Kroah-Hartman --- arch/arm64/kernel/kaslr.c | 1 + 1 file changed, 1 insertion(+) --- a/arch/arm64/kernel/kaslr.c +++ b/arch/arm64/kernel/kaslr.c @@ -88,6 +88,7 @@ u64 __init kaslr_early_init(u64 dt_phys) * we end up running with module randomization disabled. */ module_alloc_base = (u64)_etext - MODULES_VSIZE; + __flush_dcache_area(&module_alloc_base, sizeof(module_alloc_base)); /* * Try to map the FDT early. If this fails, we simply bail,