From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:38964 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751336AbdJXWzG (ORCPT ); Tue, 24 Oct 2017 18:55:06 -0400 Received: from pps.filterd (m0098417.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id v9OMrrn0077539 for ; Tue, 24 Oct 2017 18:55:05 -0400 Received: from e06smtp15.uk.ibm.com (e06smtp15.uk.ibm.com [195.75.94.111]) by mx0a-001b2d01.pphosted.com with ESMTP id 2dtcvbxeax-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Tue, 24 Oct 2017 18:55:05 -0400 Received: from localhost by e06smtp15.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 24 Oct 2017 23:55:04 +0100 Subject: Re: [PATCH v3 2/2] ima: check signature enforcement against cmdline param instead of CONFIG From: Mimi Zohar To: "Bruno E. O. Meneguele" , linux-kernel@vger.kernel.org Cc: linux-security-module@vger.kernel.org, linux-integrity@vger.kernel.org, serge@hallyn.com, james.l.morris@oracle.com, dmitry.kasatkin@gmail.com, rusty@rustcorp.com.au, jeyu@kernel.org Date: Tue, 24 Oct 2017 18:54:57 -0400 In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Message-Id: <1508885697.3164.5.camel@linux.vnet.ibm.com> Sender: linux-integrity-owner@vger.kernel.org List-ID: On Tue, 2017-10-24 at 15:37 -0200, Bruno E. O. Meneguele wrote: > When the user requests MODULE_CHECK policy and its kernel is compiled > with CONFIG_MODULE_SIG_FORCE not set, all modules would not load, just > those loaded in initram time. One option the user would have would be > set a kernel cmdline param (module.sig_enforce) to true, but the IMA > module check code doesn't rely on this value, it checks just > CONFIG_MODULE_SIG_FORCE. > > This patch solves this problem checking for the exported value of > module.sig_enforce cmdline param intead of CONFIG_MODULE_SIG_FORCE, > which holds the effective value (CONFIG || param). > > Signed-off-by: Bruno E. O. Meneguele > --- > security/integrity/ima/ima_main.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c > index e4ab8ef8016e..d11a7fcc5c8b 100644 > --- a/security/integrity/ima/ima_main.c > +++ b/security/integrity/ima/ima_main.c > @@ -356,12 +356,12 @@ void ima_post_path_mknod(struct dentry *dentry) > */ > int ima_read_file(struct file *file, enum kernel_read_file_id read_id) > { > + bool sig_enforce = is_module_sig_enforced(); > + > if (!file && read_id == READING_MODULE) { The only reason for getting here is that you're using the old module load syscall. Is there a reason for not using the new one, which passes the file descriptor? thanks, Mimi > -#ifndef CONFIG_MODULE_SIG_FORCE > - if ((ima_appraise & IMA_APPRAISE_MODULES) && > + if (!sig_enforce && (ima_appraise & IMA_APPRAISE_MODULES) && > (ima_appraise & IMA_APPRAISE_ENFORCE)) > return -EACCES; /* INTEGRITY_UNKNOWN */ > -#endif > return 0; /* We rely on module signature checking */ > } > return 0;