IMA: Handle early boot data measurement

Message ID	20200821231230.20212-1-nramas@linux.microsoft.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <SRS0=891B=B7=vger.kernel.org=linux-security-module-owner@kernel.org> From: Lakshmi Ramasubramanian <nramas@linux.microsoft.com> To: zohar@linux.ibm.com, stephen.smalley.work@gmail.com, casey@schaufler-ca.com Cc: tyhicks@linux.microsoft.com, tusharsu@linux.microsoft.com, sashal@kernel.org, jmorris@namei.org, linux-integrity@vger.kernel.org, selinux@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] IMA: Handle early boot data measurement Date: Fri, 21 Aug 2020 16:12:30 -0700 Message-Id: <20200821231230.20212-1-nramas@linux.microsoft.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk
Series	IMA: Handle early boot data measurement \| expand IMA: Handle early boot data measurement

diff --git a/security/integrity/ima/Kconfig b/security/integrity/ima/Kconfig index 080c53545ff0..bc2adab7bae2 100644 --- a/security/integrity/ima/Kconfig +++ b/security/integrity/ima/Kconfig @@ -322,7 +322,7 @@ config IMA_MEASURE_ASYMMETRIC_KEYS depends on ASYMMETRIC_PUBLIC_KEY_SUBTYPE=y default y -config IMA_QUEUE_EARLY_BOOT_KEYS +config IMA_QUEUE_EARLY_BOOT_DATA bool depends on IMA_MEASURE_ASYMMETRIC_KEYS depends on SYSTEM_TRUSTED_KEYRING diff --git a/security/integrity/ima/Makefile b/security/integrity/ima/Makefile index 67dabca670e2..6a0f9ef93bf0 100644 --- a/security/integrity/ima/Makefile +++ b/security/integrity/ima/Makefile @@ -13,4 +13,4 @@ ima-$(CONFIG_IMA_APPRAISE_MODSIG) += ima_modsig.o ima-$(CONFIG_HAVE_IMA_KEXEC) += ima_kexec.o ima-$(CONFIG_IMA_BLACKLIST_KEYRING) += ima_mok.o ima-$(CONFIG_IMA_MEASURE_ASYMMETRIC_KEYS) += ima_asymmetric_keys.o -ima-$(CONFIG_IMA_QUEUE_EARLY_BOOT_KEYS) += ima_queue_keys.o +ima-$(CONFIG_IMA_QUEUE_EARLY_BOOT_DATA) += ima_queue_data.o \ No newline at end of file diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index 00b84052c8f1..366d7cb5c22e 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -228,29 +228,36 @@ extern const char *const func_tokens[]; struct modsig; -#ifdef CONFIG_IMA_QUEUE_EARLY_BOOT_KEYS +#ifdef CONFIG_IMA_QUEUE_EARLY_BOOT_DATA /* * To track keys that need to be measured. */ -struct ima_key_entry { +struct ima_data_entry { struct list_head list; void *payload; size_t payload_len; - char *keyring_name; + const char *event_name; + const char *event_data; + enum ima_hooks func; + bool measure_payload_hash; }; -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); +void ima_init_data_queue(void); +bool ima_should_queue_data(void); +bool ima_queue_data(const char *event_name, const void *payload, + size_t payload_len, const char *event_data, + enum ima_hooks func, bool measure_payload_hash); +void ima_process_queued_data(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, - size_t payload_len) { return false; } -static inline void ima_process_queued_keys(void) {} -#endif /* CONFIG_IMA_QUEUE_EARLY_BOOT_KEYS */ +static inline void ima_init_data_queue(void) {} +static inline bool ima_should_queue_data(void) { return false; } +static inline bool ima_queue_data(const char *event_name, + const void *payload, + size_t payload_len, + const char *event_data, + enum ima_hooks func, + bool measure_payload_hash) { return false; } +static inline void ima_process_queued_data(void) {} +#endif /* CONFIG_IMA_QUEUE_EARLY_BOOT_DATA */ /* LIM API function definitions */ int ima_get_action(struct inode *inode, const struct cred *cred, u32 secid, diff --git a/security/integrity/ima/ima_asymmetric_keys.c b/security/integrity/ima/ima_asymmetric_keys.c index a74095793936..65423754765f 100644 --- a/security/integrity/ima/ima_asymmetric_keys.c +++ b/security/integrity/ima/ima_asymmetric_keys.c @@ -37,9 +37,10 @@ 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 (ima_should_queue_data()) + queued = ima_queue_data(keyring->description, payload, + payload_len, keyring->description, + KEY_CHECK, false); if (queued) return; diff --git a/security/integrity/ima/ima_init.c b/security/integrity/ima/ima_init.c index 4902fe7bd570..892894bf4af3 100644 --- a/security/integrity/ima/ima_init.c +++ b/security/integrity/ima/ima_init.c @@ -145,7 +145,7 @@ int __init ima_init(void) if (rc != 0) return rc; - ima_init_key_queue(); + ima_init_data_queue(); return rc; } diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index 5db6dc3d45aa..728557662903 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -885,9 +885,19 @@ int ima_measure_critical_data(const char *event_name, const void *buf, int buf_len, bool measure_buf_hash) { + bool queued = false; + if (!event_name || !event_data_source || !buf || !buf_len) return -EINVAL; + if (ima_should_queue_data()) + queued = ima_queue_data(event_name, buf, buf_len, + event_data_source, CRITICAL_DATA, + measure_buf_hash); + + if (queued) + return 0; + return process_buffer_measurement(NULL, buf, buf_len, event_name, CRITICAL_DATA, 0, event_data_source, measure_buf_hash); diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index 59058ce7906b..f4f095ae6f8f 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -906,7 +906,7 @@ void ima_update_policy(void) ima_update_policy_flag(); /* Custom IMA policy has been loaded */ - ima_process_queued_keys(); + ima_process_queued_data(); } /* Keep the enumeration in sync with the policy_tokens! */ diff --git a/security/integrity/ima/ima_queue_data.c b/security/integrity/ima/ima_queue_data.c new file mode 100644 index 000000000000..d466ee742377 --- /dev/null +++ b/security/integrity/ima/ima_queue_data.c @@ -0,0 +1,191 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (C) 2020 Microsoft Corporation + * + * Author: Lakshmi Ramasubramanian (nramas@linux.microsoft.com) + * + * File: ima_queue_data.c + * Enables deferred processing of data + */ + +#include <linux/workqueue.h> +#include "ima.h" + +/* + * Flag to indicate whether data can be processed + * right away or should be queued for processing later. + */ +static bool ima_process_data; + +/* + * To synchronize access to the list of data that need to be measured + */ +static DEFINE_MUTEX(ima_data_lock); +static LIST_HEAD(ima_queued_data); + +/* + * If custom IMA policy is not loaded then data queued up + * for measurement should be freed. This worker is used + * for handling this scenario. + */ +static long ima_data_queue_timeout = 300000; /* 5 Minutes */ +static void ima_data_handler(struct work_struct *work); +static DECLARE_DELAYED_WORK(ima_data_delayed_work, ima_data_handler); +static bool timer_expired; + +/* + * This worker function frees data that may still be + * queued up in case custom IMA policy was not loaded. + */ +static void ima_data_handler(struct work_struct *work) +{ + timer_expired = true; + ima_process_queued_data(); +} + +/* + * This function sets up a worker to free queued data in case + * custom IMA policy was never loaded. + */ +void ima_init_data_queue(void) +{ + schedule_delayed_work(&ima_data_delayed_work, + msecs_to_jiffies(ima_data_queue_timeout)); +} + +static void ima_free_data_entry(struct ima_data_entry *entry) +{ + if (!entry) + return; + + kvfree(entry->payload); + kfree(entry->event_name); + kfree(entry->event_data); + kfree(entry); +} + +static void *ima_kvmemdup(const void *src, size_t len) +{ + void *p = kvmalloc(len, GFP_KERNEL); + + if (p) + memcpy(p, src, len); + return p; +} + +static struct ima_data_entry *ima_alloc_data_entry(const char *event_name, + const void *payload, + size_t payload_len, + const char *event_data, + enum ima_hooks func, + bool measure_payload_hash) +{ + struct ima_data_entry *entry; + + entry = kzalloc(sizeof(*entry), GFP_KERNEL); + if (!entry) + goto out; + + /* + * Payload size may exceed the limit supported by kmalloc. + * So use kvmalloc instead. + */ + entry->payload = ima_kvmemdup(payload, payload_len); + entry->event_name = kstrdup(event_name, GFP_KERNEL); + if (event_data) + entry->event_data = kstrdup(event_data, GFP_KERNEL); + + entry->payload_len = payload_len; + entry->func = func; + entry->measure_payload_hash = measure_payload_hash; + + if (!entry->payload || !entry->event_name || + (event_data && !entry->event_data)) + goto out; + + INIT_LIST_HEAD(&entry->list); + return entry; + +out: + integrity_audit_message(AUDIT_INTEGRITY_PCR, NULL, + event_name, func_measure_str(func), + "ENOMEM", -ENOMEM, 0, -ENOMEM); + ima_free_data_entry(entry); + return NULL; +} + +bool ima_queue_data(const char *event_name, const void *payload, + size_t payload_len, const char *event_data, + enum ima_hooks func, bool measure_payload_hash) +{ + bool queued = false; + struct ima_data_entry *entry; + + entry = ima_alloc_data_entry(event_name, payload, payload_len, + event_data, func, measure_payload_hash); + if (!entry) + return false; + + mutex_lock(&ima_data_lock); + if (!ima_process_data) { + list_add_tail(&entry->list, &ima_queued_data); + queued = true; + } + mutex_unlock(&ima_data_lock); + + if (!queued) + ima_free_data_entry(entry); + + return queued; +} + +/* + * ima_process_queued_data() - process data queued for measurement + * + * This function sets ima_process_data to true and processes queued data. + * From here on data will be processed right away (not queued). + */ +void ima_process_queued_data(void) +{ + struct ima_data_entry *entry, *tmp; + bool process = false; + + if (ima_process_data) + return; + + /* + * Since ima_process_data is set to true, any new data will be + * processed immediately and not be queued to ima_queued_data list. + * First one setting the ima_process_data flag to true will + * process the queued data. + */ + mutex_lock(&ima_data_lock); + if (!ima_process_data) { + ima_process_data = true; + process = true; + } + mutex_unlock(&ima_data_lock); + + if (!process) + return; + + if (!timer_expired) + cancel_delayed_work_sync(&ima_data_delayed_work); + + list_for_each_entry_safe(entry, tmp, &ima_queued_data, list) { + if (!timer_expired) + process_buffer_measurement(NULL, entry->payload, + entry->payload_len, + entry->event_name, + entry->func, 0, + entry->event_data, + entry->measure_payload_hash); + list_del(&entry->list); + ima_free_data_entry(entry); + } +} + +inline bool ima_should_queue_data(void) +{ + return !ima_process_data; +} diff --git a/security/integrity/ima/ima_queue_keys.c b/security/integrity/ima/ima_queue_keys.c deleted file mode 100644 index c2f2ad34f9b7..000000000000 --- a/security/integrity/ima/ima_queue_keys.c +++ /dev/null @@ -1,175 +0,0 @@ -// 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 - */ - -#include <linux/workqueue.h> -#include <keys/asymmetric-type.h> -#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); - -/* - * 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) { - 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; - const char *audit_cause = "ENOMEM"; - 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) { - integrity_audit_message(AUDIT_INTEGRITY_PCR, NULL, - keyring->description, - func_measure_str(KEY_CHECK), - audit_cause, rc, 0, 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; - - if (!timer_expired) - cancel_delayed_work_sync(&ima_keys_delayed_work); - - list_for_each_entry_safe(entry, tmp, &ima_keys, list) { - if (!timer_expired) - process_buffer_measurement(NULL, entry->payload, - entry->payload_len, - entry->keyring_name, - KEY_CHECK, 0, - entry->keyring_name, - false); - list_del(&entry->list); - ima_free_key_entry(entry); - } -} - -inline bool ima_should_queue_key(void) -{ - return !ima_process_keys; -}

IMA: Handle early boot data measurement

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