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=-16.6 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_GIT,USER_IN_DEF_DKIM_WL 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 82FD7C43381 for ; Thu, 28 Feb 2019 23:13:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4F15C218AE for ; Thu, 28 Feb 2019 23:13:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="Z1+rvoth" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388095AbfB1XNC (ORCPT ); Thu, 28 Feb 2019 18:13:02 -0500 Received: from mail-it1-f202.google.com ([209.85.166.202]:36952 "EHLO mail-it1-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387939AbfB1XM5 (ORCPT ); Thu, 28 Feb 2019 18:12:57 -0500 Received: by mail-it1-f202.google.com with SMTP id q141so9824093itc.2 for ; Thu, 28 Feb 2019 15:12:57 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=8KM4GPF8H/ZA8qZu4X13d5O4g08OSMJQgTj+Sn30UNM=; b=Z1+rvothKUqR2tRl+zH/aPd+au+70MAgtzcgA3i6y553uX+/QzIYSKO8X1D+XAkhO1 0cl1XIShXKMwqyV6SVOjdEECCNLnNp+Z+xJ+RdtzV7mU2UBm1BwrIw7MdCFoZGEPgTyo 9wjPyw6bEZD8qzrKYAL4ox04cDYhyezdGMVSzQSkQgBzEUNhcY/tY/qjGleZanIupMtu /RE567QzdS2BRSNaNuv19QZraWcbeTaKiX/lUHm8VfdT/iyEnAQ/QeymKlMFvz5QzdmQ 3y7uAMlcmrGK7Cd9rmYXZVD5vZxSWp/JwAVzW5gt5Xku7HymwCegv48ovK72haVv4bgM wxgA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=8KM4GPF8H/ZA8qZu4X13d5O4g08OSMJQgTj+Sn30UNM=; b=uD2N8MnLHadTPZ4ZN025r1AT5HzmLYg6bYsoJgiijkmUDH6lxkVedgQQ+4UHg0Fp2l x3RDRZB/VmEzEUaC/7XKNQsAqsI+DZzNEC/gy/Cf2BqLdkTXnYzWJ/lgN0zJR3MqVJ5m kMuWTbjuADWGLqfhjKbSWmnYqqjHWVZa18SrDikwY63PwjoZXTOOV8Fb00jv6I9KeoDD cHjXjY3RxYy4suXkri4Mo+S4T4WnY7Zw89+y8XwWUwAmjoX30dIUb+6XlFXzR/ljMxGy gWM+0i/wRb0HC0onDhox8q/XNtDbWYWphpqC3+GcRcc5apEspGZBA5Gv6GWlg/3Guz3n 5nfw== X-Gm-Message-State: AHQUAubVHyoEgIb7LBOK0uniw0nKgN75YwUeAsS6xu7ufXQGYqRf7H/e YCrJJfAzsU5OeBZz/cSy/BCQLT5jIYI3HqVDbyMt3Q== X-Google-Smtp-Source: APXvYqyYIIPpi6LMvPSKodYDlF1Q3NR9zGkxdJ+I+B3eh9JF55kOsrbcWMzonXnT5HJXudG42GD3brjdc1roSdr3TYkjjw== X-Received: by 2002:a24:612:: with SMTP id 18mr1507443itv.7.1551395576756; Thu, 28 Feb 2019 15:12:56 -0800 (PST) Date: Thu, 28 Feb 2019 15:11:56 -0800 In-Reply-To: <20190228231203.212359-1-matthewgarrett@google.com> Message-Id: <20190228231203.212359-20-matthewgarrett@google.com> Mime-Version: 1.0 References: <20190228231203.212359-1-matthewgarrett@google.com> X-Mailer: git-send-email 2.21.0.352.gf09ad66450-goog Subject: [PATCH 20/27] Lock down module params that specify hardware parameters (eg. ioport) From: Matthew Garrett To: jmorris@namei.org Cc: linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, dhowells@redhat.com Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Archived-At: List-Archive: List-Post: From: David Howells Provided an annotation for module parameters that specify hardware parameters (such as io ports, iomem addresses, irqs, dma channels, fixed dma buffers and other types). Suggested-by: Alan Cox Signed-off-by: David Howells --- kernel/params.c | 26 +++++++++++++++++++++----- 1 file changed, 21 insertions(+), 5 deletions(-) diff --git a/kernel/params.c b/kernel/params.c index ce89f757e6da..8ac751c938f8 100644 --- a/kernel/params.c +++ b/kernel/params.c @@ -108,13 +108,19 @@ bool parameq(const char *a, const char *b) return parameqn(a, b, strlen(a)+1); } -static void param_check_unsafe(const struct kernel_param *kp) +static bool param_check_unsafe(const struct kernel_param *kp, + const char *doing) { if (kp->flags & KERNEL_PARAM_FL_UNSAFE) { pr_notice("Setting dangerous option %s - tainting kernel\n", kp->name); add_taint(TAINT_USER, LOCKDEP_STILL_OK); } + + if (kp->flags & KERNEL_PARAM_FL_HWPARAM && + kernel_is_locked_down("Command line-specified device addresses, irqs and dma channels")) + return false; + return true; } static int parse_one(char *param, @@ -144,8 +150,10 @@ static int parse_one(char *param, pr_debug("handling %s with %p\n", param, params[i].ops->set); kernel_param_lock(params[i].mod); - param_check_unsafe(¶ms[i]); - err = params[i].ops->set(val, ¶ms[i]); + if (param_check_unsafe(¶ms[i], doing)) + err = params[i].ops->set(val, ¶ms[i]); + else + err = -EPERM; kernel_param_unlock(params[i].mod); return err; } @@ -553,6 +561,12 @@ static ssize_t param_attr_show(struct module_attribute *mattr, return count; } +#ifdef CONFIG_MODULES +#define mod_name(mod) (mod)->name +#else +#define mod_name(mod) "unknown" +#endif + /* sysfs always hands a nul-terminated string in buf. We rely on that. */ static ssize_t param_attr_store(struct module_attribute *mattr, struct module_kobject *mk, @@ -565,8 +579,10 @@ static ssize_t param_attr_store(struct module_attribute *mattr, return -EPERM; kernel_param_lock(mk->mod); - param_check_unsafe(attribute->param); - err = attribute->param->ops->set(buf, attribute->param); + if (param_check_unsafe(attribute->param, mod_name(mk->mod))) + err = attribute->param->ops->set(buf, attribute->param); + else + err = -EPERM; kernel_param_unlock(mk->mod); if (!err) return len; -- 2.21.0.352.gf09ad66450-goog