From patchwork Thu Jan 23 01:32:04 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lakshmi Ramasubramanian X-Patchwork-Id: 11346657 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 49AD66C1 for ; Thu, 23 Jan 2020 01:32:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1E5752467A for ; Thu, 23 Jan 2020 01:32:21 +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 S1726780AbgAWBcN (ORCPT ); Wed, 22 Jan 2020 20:32:13 -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-integrity-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-integrity@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; +} From patchwork Thu Jan 23 01:32:05 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lakshmi Ramasubramanian X-Patchwork-Id: 11346663 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 8501F6C1 for ; Thu, 23 Jan 2020 01:32:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5D0B82467A for ; Thu, 23 Jan 2020 01:32:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="D6Goiyvf" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726204AbgAWBcN (ORCPT ); Wed, 22 Jan 2020 20:32:13 -0500 Received: from linux.microsoft.com ([13.77.154.182]:55886 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726054AbgAWBcM (ORCPT ); Wed, 22 Jan 2020 20:32:12 -0500 Received: from nramas-ThinkStation-P520.corp.microsoft.com (unknown [131.107.174.108]) by linux.microsoft.com (Postfix) with ESMTPSA id B76C0200881F; Wed, 22 Jan 2020 17:32:11 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com B76C0200881F DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1579743131; bh=yzBpJmLcmKpLbuMp++dNzRjccHLIRwtlfv7PZnss+EY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=D6Goiyvf+e4WRHC7bwFHhDpvBKDZPqCuqUvkcipCyrJOzhd9ivKsVX0e9hX34tg2n NhOiPfQtsp/hY1Qmo66hgHKWlH32yjpUfWwrRwofUzOl8Ysha92BlrgD3q3YbxHup5 GksSY1/kjUlpKP34205DivG2c4ikLQVwyK53qIN0= 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 2/3] IMA: Call workqueue functions to measure queued keys Date: Wed, 22 Jan 2020 17:32:05 -0800 Message-Id: <20200123013206.8499-3-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-integrity-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org Measuring keys requires a custom IMA policy to be loaded. Keys should be queued for measurement if a custom IMA policy is not yet loaded. Keys queued for measurement, if any, should be processed when a custom IMA policy is loaded. This patch updates the IMA hook function ima_post_key_create_or_update() to queue the key if a custom IMA policy has not yet been loaded. And, ima_update_policy() function, which is called when a custom IMA policy is loaded, is updated to process queued keys. Signed-off-by: Lakshmi Ramasubramanian --- security/integrity/ima/ima_asymmetric_keys.c | 8 ++++++++ security/integrity/ima/ima_policy.c | 3 +++ 2 files changed, 11 insertions(+) diff --git a/security/integrity/ima/ima_asymmetric_keys.c b/security/integrity/ima/ima_asymmetric_keys.c index fea2e7dd3b09..7678f0e3e84d 100644 --- a/security/integrity/ima/ima_asymmetric_keys.c +++ b/security/integrity/ima/ima_asymmetric_keys.c @@ -30,6 +30,8 @@ void ima_post_key_create_or_update(struct key *keyring, struct key *key, const void *payload, size_t payload_len, unsigned long flags, bool create) { + bool queued = false; + /* Only asymmetric keys are handled by this hook. */ if (key->type != &key_type_asymmetric) return; @@ -37,6 +39,12 @@ void ima_post_key_create_or_update(struct key *keyring, struct key *key, if (!payload || (payload_len == 0)) return; + if (ima_should_queue_key()) + queued = ima_queue_key(keyring, payload, payload_len); + + if (queued) + return; + /* * keyring->description points to the name of the keyring * (such as ".builtin_trusted_keys", ".ima", etc.) to diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index 3b16b190ae9b..f2fc24511cf4 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -807,6 +807,9 @@ void ima_update_policy(void) kfree(arch_policy_entry); } ima_update_policy_flag(); + + /* Custom IMA policy has been loaded */ + ima_process_queued_keys(); } /* Keep the enumeration in sync with the policy_tokens! */ From patchwork Thu Jan 23 01:32:06 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lakshmi Ramasubramanian X-Patchwork-Id: 11346661 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 1DCF56C1 for ; Thu, 23 Jan 2020 01:32:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EFB9B2467B for ; Thu, 23 Jan 2020 01:32:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="bLJGHieE" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726054AbgAWBcN (ORCPT ); Wed, 22 Jan 2020 20:32:13 -0500 Received: from linux.microsoft.com ([13.77.154.182]:55890 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726061AbgAWBcN (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 DCF4D20B479A; Wed, 22 Jan 2020 17:32:11 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com DCF4D20B479A DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1579743131; bh=/nY96uoMJp5UFNLYIHALLqmSHnbOJjuKRmMufwC67lI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bLJGHieEUym6AsETnkXTh8AQeVB67Um1sblhLxphFyGzN8N417Wue0Rj48P0vu1CH VWBOUTWlFpste+bRKvIwW9q5iPWYK2LUZwUjGTlOjuuv6Px+WcWVnOlwADzr6dVwqm XVhhIn4H9wM0JZhuAJ98YaQSxTFEAfuUwK9kQaNQ= 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 3/3] IMA: Defined delayed workqueue to free the queued keys Date: Wed, 22 Jan 2020 17:32:06 -0800 Message-Id: <20200123013206.8499-4-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-integrity-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org Keys queued for measurement should be freed if a custom IMA policy was not loaded. Otherwise, the keys will remain queued forever consuming kernel memory. This patch defines a delayed workqueue to handle the above scenario. The workqueue handler is setup to execute 5 minutes after IMA initialization is completed. If a custom IMA policy is loaded before the workqueue handler is scheduled to execute, the workqueue task is cancelled and any queued keys are processed for measurement. But if a custom policy was not loaded then the queued keys are just freed when the delayed workqueue handler is run. Signed-off-by: Lakshmi Ramasubramanian Reported-by: kernel test robot # sleeping function called from invalid context Reported-by: kbuild test robot # redefinition of ima_init_key_queue() function. --- security/integrity/ima/ima.h | 2 ++ security/integrity/ima/ima_init.c | 8 ++++- security/integrity/ima/ima_queue_keys.c | 44 ++++++++++++++++++++++--- 3 files changed, 48 insertions(+), 6 deletions(-) diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index 905ed2f7f778..64317d95363e 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -215,11 +215,13 @@ struct ima_key_entry { size_t payload_len; char *keyring_name; }; +void ima_init_key_queue(void); 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 void ima_init_key_queue(void) {} static inline bool ima_should_queue_key(void) { return false; } static inline bool ima_queue_key(struct key *keyring, const void *payload, diff --git a/security/integrity/ima/ima_init.c b/security/integrity/ima/ima_init.c index 5d55ade5f3b9..195cb4079b2b 100644 --- a/security/integrity/ima/ima_init.c +++ b/security/integrity/ima/ima_init.c @@ -131,5 +131,11 @@ int __init ima_init(void) ima_init_policy(); - return ima_fs_init(); + rc = ima_fs_init(); + if (rc != 0) + return rc; + + ima_init_key_queue(); + + return rc; } diff --git a/security/integrity/ima/ima_queue_keys.c b/security/integrity/ima/ima_queue_keys.c index 9b561f2b86db..c87c72299191 100644 --- a/security/integrity/ima/ima_queue_keys.c +++ b/security/integrity/ima/ima_queue_keys.c @@ -10,6 +10,7 @@ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt +#include #include #include "ima.h" @@ -25,6 +26,36 @@ static bool ima_process_keys; static DEFINE_MUTEX(ima_keys_lock); static LIST_HEAD(ima_keys); +/* + * If custom IMA policy is not loaded then keys queued up + * for measurement should be freed. This worker is used + * for handling this scenario. + */ +static long ima_key_queue_timeout = 300000; /* 5 Minutes */ +static void ima_keys_handler(struct work_struct *work); +static DECLARE_DELAYED_WORK(ima_keys_delayed_work, ima_keys_handler); +static bool timer_expired; + +/* + * This worker function frees keys that may still be + * queued up in case custom IMA policy was not loaded. + */ +static void ima_keys_handler(struct work_struct *work) +{ + timer_expired = true; + ima_process_queued_keys(); +} + +/* + * This function sets up a worker to free queued keys in case + * custom IMA policy was never loaded. + */ +void ima_init_key_queue(void) +{ + schedule_delayed_work(&ima_keys_delayed_work, + msecs_to_jiffies(ima_key_queue_timeout)); +} + static void ima_free_key_entry(struct ima_key_entry *entry) { if (entry) { @@ -119,13 +150,16 @@ void ima_process_queued_keys(void) if (!process) return; + if (!timer_expired) + cancel_delayed_work_sync(&ima_keys_delayed_work); 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); + if (!timer_expired) + 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); }