From patchwork Fri Jan 3 19:54:32 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lakshmi Ramasubramanian X-Patchwork-Id: 11317367 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id E246A14E3 for ; Fri, 3 Jan 2020 19:54:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C259521835 for ; Fri, 3 Jan 2020 19:54:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="s+ylC9Vx" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728639AbgACTyn (ORCPT ); Fri, 3 Jan 2020 14:54:43 -0500 Received: from linux.microsoft.com ([13.77.154.182]:35944 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728546AbgACTym (ORCPT ); Fri, 3 Jan 2020 14:54:42 -0500 Received: from nramas-ThinkStation-P520.corp.microsoft.com (unknown [131.107.174.108]) by linux.microsoft.com (Postfix) with ESMTPSA id EF3C92010C33; Fri, 3 Jan 2020 11:54:41 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com EF3C92010C33 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1578081282; bh=Z1n2LzQpaCgWEDxC/fs/cZCzWQOEqpq+cd0+IedtQM4=; h=From:To:Cc:Subject:Date:From; b=s+ylC9Vxkkcm0+bCBAIvfX7bVTOkBHZphgHD35s2dEevT7yj2qS4UB9VimYqHtK9y 2mleI2CwcRvPqD8pnKxWFTfZC3LtYxs1AWxCK1reTSTgS7BJf3I8CPnNdXkxxCbka9 ofnrU2FthUNgSIMj1rssnJfGfP9YSEx88rljjjWo= From: Lakshmi Ramasubramanian To: zohar@linux.ibm.com, linux-integrity@vger.kernel.org Cc: James.Bottomley@HansenPartnership.com, eric.snowberg@oracle.com, dhowells@redhat.com, mathew.j.martineau@linux.intel.com, matthewgarrett@google.com, sashal@kernel.org, jamorris@linux.microsoft.com, linux-kernel@vger.kernel.org, keyrings@vger.kernel.org Subject: [PATCH v7 0/3] IMA: Deferred measurement of keys Date: Fri, 3 Jan 2020 11:54:32 -0800 Message-Id: <20200103195435.2647-1-nramas@linux.microsoft.com> X-Mailer: git-send-email 2.17.1 Sender: linux-integrity-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org The IMA subsystem supports measuring asymmetric keys when the key is created or updated[1]. But keys created or updated before a custom IMA policy is loaded are currently not measured. This includes keys added, for instance, to either the .ima or .builtin_trusted_keys keyrings, which happens early in the boot process. Measuring the early boot keys, by design, requires loading a custom IMA policy. This change adds support for queuing keys created or updated before a custom IMA policy is loaded. The queued keys are processed when a custom policy is loaded. Keys created or updated after a custom policy is loaded are measured immediately (not queued). In the case when a custom policy is not loaded within 5 minutes of IMA initialization, the queued keys are freed. [1] https://lore.kernel.org/linux-integrity/20191211164707.4698-1-nramas@linux.microsoft.com/ Testing performed: * Ran kernel self-test following the instructions given in https://www.kernel.org/doc/Documentation/kselftest.txt * Ran the lkp-tests using the job script provided by kernel test robot * Booted the kernel with this change. * Added .builtin_trusted_keys in "keyrings=" option in the IMA policy and verified the keys added to this keyring are measured. * Specified only func=KEY_CHECK and not "keyrings=" option, and verified the keys added to builtin_trusted_keys keyring are processed. * Added keys at runtime and verified they are measured if the IMA policy permitted. => For example, added keys to .ima keyring and verified. Changelog: v7 => Updated cover letter per Mimi's suggestions. => Updated "Reported-by" tag to be specific about the issues fixed in the patch. v6 => Replaced mutex with a spinlock to sychronize access to queued keys. This fixes the problem reported by "kernel test robot " https://lore.kernel.org/linux-integrity/2a831fe9-30e5-63b4-af10-a69f327f7fb7@linux.microsoft.com/T/#t => Changed ima_queue_key() to a static function. This fixes the issue reported by "kbuild test robot " https://lore.kernel.org/linux-integrity/1577370464.4487.10.camel@linux.ibm.com/ => Added the patch to free the queued keys if a custom IMA policy was not loaded to this patch set. v5 => Removed temp keys list in ima_process_queued_keys() v4 => Check and set ima_process_keys flag with mutex held. v3 => Defined ima_process_keys flag to be static. => Set ima_process_keys with ima_keys_mutex held. => Added a comment in ima_process_queued_keys() function to state the use of temporary list for keys. v2 => Rebased the changes to v5.5-rc1 => Updated function names, variable names, and code comments to be less verbose. v1 => Code cleanup v0 => Based changes on v5.4-rc8 => The following patchsets should be applied in that order https://lore.kernel.org/linux-integrity/1572492694-6520-1-git-send-email-zohar@linux.ibm.com https://lore.kernel.org/linux-integrity/20191204224131.3384-1-nramas@linux.microsoft.com/ => Added functions to queue and dequeue keys, and process the queued keys when custom IMA policies are applied. Lakshmi Ramasubramanian (3): IMA: Define workqueue for early boot key measurements IMA: Call workqueue functions to measure queued keys IMA: Defined timer to free queued keys security/integrity/ima/ima.h | 17 ++ security/integrity/ima/ima_asymmetric_keys.c | 159 +++++++++++++++++++ security/integrity/ima/ima_init.c | 8 +- security/integrity/ima/ima_policy.c | 3 + 4 files changed, 186 insertions(+), 1 deletion(-)