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=-17.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,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 CBEB9C33CAF for ; Thu, 23 Jan 2020 01:32:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9696B24125 for ; Thu, 23 Jan 2020 01:32:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="ouEXrAVl" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728655AbgAWBcO (ORCPT ); Wed, 22 Jan 2020 20:32:14 -0500 Received: from linux.microsoft.com ([13.77.154.182]:55872 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726026AbgAWBcN (ORCPT ); Wed, 22 Jan 2020 20:32:13 -0500 Received: from nramas-ThinkStation-P520.corp.microsoft.com (unknown [131.107.174.108]) by linux.microsoft.com (Postfix) with ESMTPSA id 9384320B4798; Wed, 22 Jan 2020 17:32:11 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 9384320B4798 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1579743131; bh=vhWNJFcZ1lKSjddLmIJo2O1KjzBodPswRirIh7RqTkk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ouEXrAVl9gdJWmOKL++Nqz2rODK3lb/0oUugvQ8cMFybmZKw5nokV6QC2wYJGcycA VErAoDMDvIYqRWglGP50d9bCDrg643zbXvsC8X/9EIRprhvLewPnpC+IOQUHv55U21 4DwE/Xoojmls4f59gBvp3z3NLpAXyRabo9/3URWI= From: Lakshmi Ramasubramanian To: zohar@linux.ibm.com, James.Bottomley@HansenPartnership.com, linux-integrity@vger.kernel.org Cc: sashal@kernel.org, dhowells@redhat.com, linux-kernel@vger.kernel.org, keyrings@vger.kernel.org Subject: [PATCH v9 1/3] IMA: Define workqueue for early boot key measurements Date: Wed, 22 Jan 2020 17:32:04 -0800 Message-Id: <20200123013206.8499-2-nramas@linux.microsoft.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200123013206.8499-1-nramas@linux.microsoft.com> References: <20200123013206.8499-1-nramas@linux.microsoft.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Measuring keys requires a custom IMA policy to be loaded. Keys created or updated before a custom IMA policy is loaded should be queued and the keys should be processed after a custom policy is loaded. This patch defines workqueue for queuing keys when a custom IMA policy has not yet been loaded. An intermediate Kconfig boolean option namely IMA_QUEUE_EARLY_BOOT_KEYS is used to declare the workqueue functions. A flag namely ima_process_keys is used to check if the key should be queued or should be processed immediately. Signed-off-by: Lakshmi Ramasubramanian --- security/integrity/ima/Kconfig | 5 + security/integrity/ima/Makefile | 1 + security/integrity/ima/ima.h | 22 ++++ security/integrity/ima/ima_queue_keys.c | 137 ++++++++++++++++++++++++ 4 files changed, 165 insertions(+) create mode 100644 security/integrity/ima/ima_queue_keys.c diff --git a/security/integrity/ima/Kconfig b/security/integrity/ima/Kconfig index 6bec78eeeae8..711ff10fa36e 100644 --- a/security/integrity/ima/Kconfig +++ b/security/integrity/ima/Kconfig @@ -317,3 +317,8 @@ config IMA_MEASURE_ASYMMETRIC_KEYS depends on ASYMMETRIC_PUBLIC_KEY_SUBTYPE=y default y +config IMA_QUEUE_EARLY_BOOT_KEYS + bool + depends on IMA_MEASURE_ASYMMETRIC_KEYS + depends on SYSTEM_TRUSTED_KEYRING + default y diff --git a/security/integrity/ima/Makefile b/security/integrity/ima/Makefile index 3e9d0ad68c7b..064a256f8725 100644 --- a/security/integrity/ima/Makefile +++ b/security/integrity/ima/Makefile @@ -13,3 +13,4 @@ ima-$(CONFIG_IMA_APPRAISE_MODSIG) += ima_modsig.o ima-$(CONFIG_HAVE_IMA_KEXEC) += ima_kexec.o obj-$(CONFIG_IMA_BLACKLIST_KEYRING) += ima_mok.o obj-$(CONFIG_IMA_MEASURE_ASYMMETRIC_KEYS) += ima_asymmetric_keys.o +obj-$(CONFIG_IMA_QUEUE_EARLY_BOOT_KEYS) += ima_queue_keys.o diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index f06238e41a7c..905ed2f7f778 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -205,6 +205,28 @@ extern const char *const func_tokens[]; struct modsig; +#ifdef CONFIG_IMA_QUEUE_EARLY_BOOT_KEYS +/* + * To track keys that need to be measured. + */ +struct ima_key_entry { + struct list_head list; + void *payload; + size_t payload_len; + char *keyring_name; +}; +bool ima_should_queue_key(void); +bool ima_queue_key(struct key *keyring, const void *payload, + size_t payload_len); +void ima_process_queued_keys(void); +#else +static inline bool ima_should_queue_key(void) { return false; } +static inline bool ima_queue_key(struct key *keyring, + const void *payload, + size_t payload_len) { return false; } +static inline void ima_process_queued_keys(void) {} +#endif /* CONFIG_IMA_QUEUE_EARLY_BOOT_KEYS */ + /* LIM API function definitions */ int ima_get_action(struct inode *inode, const struct cred *cred, u32 secid, int mask, enum ima_hooks func, int *pcr, diff --git a/security/integrity/ima/ima_queue_keys.c b/security/integrity/ima/ima_queue_keys.c new file mode 100644 index 000000000000..9b561f2b86db --- /dev/null +++ b/security/integrity/ima/ima_queue_keys.c @@ -0,0 +1,137 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (C) 2019 Microsoft Corporation + * + * Author: Lakshmi Ramasubramanian (nramas@linux.microsoft.com) + * + * File: ima_queue_keys.c + * Enables deferred processing of keys + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include "ima.h" + +/* + * Flag to indicate whether a key can be processed + * right away or should be queued for processing later. + */ +static bool ima_process_keys; + +/* + * To synchronize access to the list of keys that need to be measured + */ +static DEFINE_MUTEX(ima_keys_lock); +static LIST_HEAD(ima_keys); + +static void ima_free_key_entry(struct ima_key_entry *entry) +{ + if (entry) { + kfree(entry->payload); + kfree(entry->keyring_name); + kfree(entry); + } +} + +static struct ima_key_entry *ima_alloc_key_entry(struct key *keyring, + const void *payload, + size_t payload_len) +{ + int rc = 0; + struct ima_key_entry *entry; + + entry = kzalloc(sizeof(*entry), GFP_KERNEL); + if (entry) { + entry->payload = kmemdup(payload, payload_len, GFP_KERNEL); + entry->keyring_name = kstrdup(keyring->description, + GFP_KERNEL); + entry->payload_len = payload_len; + } + + if ((entry == NULL) || (entry->payload == NULL) || + (entry->keyring_name == NULL)) { + rc = -ENOMEM; + goto out; + } + + INIT_LIST_HEAD(&entry->list); + +out: + if (rc) { + ima_free_key_entry(entry); + entry = NULL; + } + + return entry; +} + +bool ima_queue_key(struct key *keyring, const void *payload, + size_t payload_len) +{ + bool queued = false; + struct ima_key_entry *entry; + + entry = ima_alloc_key_entry(keyring, payload, payload_len); + if (!entry) + return false; + + mutex_lock(&ima_keys_lock); + if (!ima_process_keys) { + list_add_tail(&entry->list, &ima_keys); + queued = true; + } + mutex_unlock(&ima_keys_lock); + + if (!queued) + ima_free_key_entry(entry); + + return queued; +} + +/* + * ima_process_queued_keys() - process keys queued for measurement + * + * This function sets ima_process_keys to true and processes queued keys. + * From here on keys will be processed right away (not queued). + */ +void ima_process_queued_keys(void) +{ + struct ima_key_entry *entry, *tmp; + bool process = false; + + if (ima_process_keys) + return; + + /* + * Since ima_process_keys is set to true, any new key will be + * processed immediately and not be queued to ima_keys list. + * First one setting the ima_process_keys flag to true will + * process the queued keys. + */ + mutex_lock(&ima_keys_lock); + if (!ima_process_keys) { + ima_process_keys = true; + process = true; + } + mutex_unlock(&ima_keys_lock); + + if (!process) + return; + + + list_for_each_entry_safe(entry, tmp, &ima_keys, list) { + process_buffer_measurement(entry->payload, + entry->payload_len, + entry->keyring_name, + KEY_CHECK, 0, + entry->keyring_name); + list_del(&entry->list); + ima_free_key_entry(entry); + } +} + +inline bool ima_should_queue_key(void) +{ + return !ima_process_keys; +} -- 2.17.1