From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751927AbdFZOnI (ORCPT ); Mon, 26 Jun 2017 10:43:08 -0400 Received: from lhrrgout.huawei.com ([194.213.3.17]:29301 "EHLO lhrrgout.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751386AbdFZOmq (ORCPT ); Mon, 26 Jun 2017 10:42:46 -0400 From: Igor Stoppa To: , , , CC: , , , , , , , , , "Igor Stoppa" Subject: [PATCH v7 0/3] ro protection for dynamic data Date: Mon, 26 Jun 2017 17:41:13 +0300 Message-ID: <20170626144116.27599-1-igor.stoppa@huawei.com> X-Mailer: git-send-email 2.9.3 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.122.225.51] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A020203.59511D56.02CD,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=0.0.0.0, so=2013-06-18 04:22:30, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: 3c568d405c147a5d8084f326a63bb083 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, please consider for inclusion. This patch introduces the possibility of protecting memory that has been allocated dynamically. The memory is managed in pools: when a pool is made R/O, all the memory that is part of it, will become R/O. A R/O pool can be destroyed to recover its memory, but it cannot be turned back into R/W mode. This is intentional. This feature is meant for data that doesn't need further modifications, after initialization. An example is provided, showing how to turn into a boot-time option the writable state of the security hooks. Prior to this patch, it was a compile-time option. This is made possible, thanks to Tetsuo Handa's rework of the hooks structure (included in the patchset). Changes since the v6 version: - complete rewrite, to use the genalloc library - added sysfs interface for tracking of active pools The only question still open is if there should be a possibility for unprotecting a memory pool in other cases than destruction. The only cases found for this topic are: - protecting the LSM header structure between creation and insertion of a security module that was not built as part of the kernel (but the module can protect the headers after it has loaded) - unloading SELinux from RedHat, if the system has booted, but no policy has been loaded yet - this feature is going away, according to Casey. Igor Stoppa (2): Protectable memory support Make LSM Writable Hooks a command line option Tetsuo Handa (1): LSM: Convert security_hook_heads into explicit array of struct list_head arch/Kconfig | 1 + include/linux/lsm_hooks.h | 420 ++++++++++++++++++++--------------------- include/linux/page-flags.h | 2 + include/linux/pmalloc.h | 111 +++++++++++ include/trace/events/mmflags.h | 1 + init/main.c | 2 + lib/Kconfig | 1 + lib/genalloc.c | 4 +- mm/Makefile | 1 + mm/pmalloc.c | 346 +++++++++++++++++++++++++++++++++ mm/usercopy.c | 24 ++- security/security.c | 49 +++-- 12 files changed, 726 insertions(+), 236 deletions(-) create mode 100644 include/linux/pmalloc.h create mode 100644 mm/pmalloc.c -- 2.9.3