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[209.132.180.67]) by mx.google.com with ESMTP id 41si9554984plb.391.2019.04.03.17.35.53; Wed, 03 Apr 2019 17:36:07 -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=@google.com header.s=20161025 header.b=S5mjTTfJ; 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; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727773AbfDDAdo (ORCPT + 99 others); Wed, 3 Apr 2019 20:33:44 -0400 Received: from mail-pl1-f201.google.com ([209.85.214.201]:48083 "EHLO mail-pl1-f201.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727523AbfDDAdm (ORCPT ); Wed, 3 Apr 2019 20:33:42 -0400 Received: by mail-pl1-f201.google.com with SMTP id 1so617170ply.14 for ; Wed, 03 Apr 2019 17:33:42 -0700 (PDT) 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=e4y+ZQyWx4Nt0qrBtIg+M07eqiLDT0f94JTcXc0xkLQ=; b=S5mjTTfJvgYmtb0pk9yg2qX2kfDWmzoiE39gwWHtmT8W4jzuAMrOa2sDqQKxKxPa7h qjEP64Mrg6re+iDsC52FxgSOL8Nwvj5Qn+T9WlymnKpX+aDImqUrqqmltqI/0nuYY6zp HhSJeJSUCkfcP3v0hk0t0fKyRgxkTcCFNSnCCe5HCEi/GKcv7tV3CHSplyaFxYum0QUr uWyxlJtZwG98ThTRKjLMLMiCka/mfEjDJkkj8JE2WgCrYlSa3cpdxQ0A8pexRpHyJIpd KtAViuScjJnu54WbD+xdae1wvImjb/+YoDbJCokDwSzH/cvDBOimigtYjc3fP3mR6Pj/ 6kmg== 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=e4y+ZQyWx4Nt0qrBtIg+M07eqiLDT0f94JTcXc0xkLQ=; b=O7sM511lzZIBtzVhi0BtYlV5bMZGbmjf0cXeXGY+vjGtdZeALxP4p335nAtnE5Px1j bDyNc1WE1SkG2GFPGgwu7GYXEBx/mdI5sDH9iPsL0n9pNkQF3/meIR+GMW4PMfisd1Xr xPuRTN5iWN7kgKsS1BSZAml6X1WWPfpmnoQ4l+ginaobYnqrDO2DgbJHk3+uyCoSou7r DSWLaBg116QSFNDDQ4pHNfbmpPoddRTq7DrIHaiHLZY4EtnvBjcam4q8iXjTI+yI8vxc w3rEvLFk5gyzTJg/I4TvgbH0pcVPIbVKs9HfienDac7rcl+ZmJcXqJvlXoTSgt9Uu7SQ J4pA== X-Gm-Message-State: APjAAAU2AGI9cuf3EM3pZrEkRDRsA2mnRFcx3smYwpM/Q+TqdvdU3Sa2 /0Z78u6YqqFFQfv28ZgfCBdKgARdi8Q4i/h9vl3osA== X-Received: by 2002:a63:a54d:: with SMTP id r13mr65091pgu.126.1554338021751; Wed, 03 Apr 2019 17:33:41 -0700 (PDT) Date: Wed, 3 Apr 2019 17:32:40 -0700 In-Reply-To: <20190404003249.14356-1-matthewgarrett@google.com> Message-Id: <20190404003249.14356-19-matthewgarrett@google.com> Mime-Version: 1.0 References: <20190404003249.14356-1-matthewgarrett@google.com> X-Mailer: git-send-email 2.21.0.392.gf8f6787159e-goog Subject: [PATCH V32 18/27] 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, linux-api@vger.kernel.org, luto@kernel.org, Alan Cox , Matthew Garrett 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 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 Signed-off-by: Matthew Garrett --- kernel/params.c | 26 +++++++++++++++++++++----- 1 file changed, 21 insertions(+), 5 deletions(-) diff --git a/kernel/params.c b/kernel/params.c index ce89f757e6da..da1297f7cc26 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", LOCKDOWN_INTEGRITY)) + 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; -- 2.21.0.392.gf8f6787159e-goog