From patchwork Thu Jul 30 03:47:22 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lakshmi Ramasubramanian X-Patchwork-Id: 11692277 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 95308722 for ; Thu, 30 Jul 2020 03:47:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 78893206E6 for ; Thu, 30 Jul 2020 03:47:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="ZfhQxxF+" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728579AbgG3Drq (ORCPT ); Wed, 29 Jul 2020 23:47:46 -0400 Received: from linux.microsoft.com ([13.77.154.182]:53434 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726806AbgG3Dra (ORCPT ); Wed, 29 Jul 2020 23:47:30 -0400 Received: from localhost.localdomain (c-73-42-176-67.hsd1.wa.comcast.net [73.42.176.67]) by linux.microsoft.com (Postfix) with ESMTPSA id 8194D20B490A; Wed, 29 Jul 2020 20:47:29 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 8194D20B490A DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1596080849; bh=g8P3tVPFZK672hTvxoboLR7QmXQ2fY2BSiKz+mu9g08=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZfhQxxF+oSD31YlSb3OqN0hz2FEojL2tyh8RZ6OmqhZg/KpjkiGri677MWn6NkKOd TYQvn4ZxpJBelxUrcEYU+Hi9YnYuBZEPzPx/qA6HWJoAvVc1SlYUFtPePmQ9b//dPv 9M3glWGXPG3YLV+at7ed43S9Ddh0MAlF+lTflDHw= From: Lakshmi Ramasubramanian To: zohar@linux.ibm.com, stephen.smalley.work@gmail.com, casey@schaufler-ca.com Cc: tyhicks@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 v5 2/4] IMA: Define IMA hooks to measure LSM state and policy Date: Wed, 29 Jul 2020 20:47:22 -0700 Message-Id: <20200730034724.3298-3-nramas@linux.microsoft.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200730034724.3298-1-nramas@linux.microsoft.com> References: <20200730034724.3298-1-nramas@linux.microsoft.com> MIME-Version: 1.0 Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: IMA subsystem needs to define IMA hooks that the security modules can call to measure state and policy data. Define two new IMA hooks, namely ima_lsm_state() and ima_lsm_policy(), that the security modules can call to measure LSM state and LSM policy respectively. Return the status of the measurement operation from these two IMA hooks. Signed-off-by: Lakshmi Ramasubramanian Reviewed-by: Tyler Hicks --- include/linux/ima.h | 14 +++++++++ security/integrity/ima/ima.h | 6 ++-- security/integrity/ima/ima_main.c | 50 ++++++++++++++++++++++++++----- 3 files changed, 60 insertions(+), 10 deletions(-) diff --git a/include/linux/ima.h b/include/linux/ima.h index d15100de6cdd..442ca0dce3c8 100644 --- a/include/linux/ima.h +++ b/include/linux/ima.h @@ -26,6 +26,10 @@ extern int ima_post_read_file(struct file *file, void *buf, loff_t size, extern void ima_post_path_mknod(struct dentry *dentry); extern int ima_file_hash(struct file *file, char *buf, size_t buf_size); extern void ima_kexec_cmdline(int kernel_fd, const void *buf, int size); +extern int ima_measure_lsm_state(const char *lsm_event_name, const void *buf, + int size); +extern int ima_measure_lsm_policy(const char *lsm_event_name, const void *buf, + int size); #ifdef CONFIG_IMA_KEXEC extern void ima_add_kexec_buffer(struct kimage *image); @@ -104,6 +108,16 @@ static inline int ima_file_hash(struct file *file, char *buf, size_t buf_size) } static inline void ima_kexec_cmdline(int kernel_fd, const void *buf, int size) {} +static inline int ima_measure_lsm_state(const char *lsm_event_name, + const void *buf, int size) +{ + return -EOPNOTSUPP; +} +static inline int ima_measure_lsm_policy(const char *lsm_event_name, + const void *buf, int size) +{ + return -EOPNOTSUPP; +} #endif /* CONFIG_IMA */ #ifndef CONFIG_IMA_KEXEC diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index 1b5f4b2f17d0..8ed9f5e1dd40 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -267,9 +267,9 @@ void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file, struct evm_ima_xattr_data *xattr_value, int xattr_len, const struct modsig *modsig, int pcr, struct ima_template_desc *template_desc); -void process_buffer_measurement(struct inode *inode, const void *buf, int size, - const char *eventname, enum ima_hooks func, - int pcr, const char *keyring); +int process_buffer_measurement(struct inode *inode, const void *buf, int size, + const char *eventname, enum ima_hooks func, + int pcr, const char *keyring); void ima_audit_measurement(struct integrity_iint_cache *iint, const unsigned char *filename); int ima_alloc_init_template(struct ima_event_data *event_data, diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index 8a91711ca79b..74d421e40c8f 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -736,9 +736,9 @@ int ima_load_data(enum kernel_load_data_id id) * * Based on policy, the buffer is measured into the ima log. */ -void process_buffer_measurement(struct inode *inode, const void *buf, int size, - const char *eventname, enum ima_hooks func, - int pcr, const char *keyring) +int process_buffer_measurement(struct inode *inode, const void *buf, int size, + const char *eventname, enum ima_hooks func, + int pcr, const char *keyring) { int ret = 0; const char *audit_cause = "ENOMEM"; @@ -758,7 +758,7 @@ void process_buffer_measurement(struct inode *inode, const void *buf, int size, u32 secid; if (!ima_policy_flag) - return; + return 0; /* * Both LSM hooks and auxilary based buffer measurements are @@ -772,7 +772,7 @@ void process_buffer_measurement(struct inode *inode, const void *buf, int size, action = ima_get_action(inode, current_cred(), secid, 0, func, &pcr, &template, keyring); if (!(action & IMA_MEASURE)) - return; + return 0; } if (!pcr) @@ -787,7 +787,7 @@ void process_buffer_measurement(struct inode *inode, const void *buf, int size, pr_err("template %s init failed, result: %d\n", (strlen(template->name) ? template->name : template->fmt), ret); - return; + return ret; } } @@ -819,7 +819,7 @@ void process_buffer_measurement(struct inode *inode, const void *buf, int size, func_measure_str(func), audit_cause, ret, 0, ret); - return; + return ret; } /** @@ -846,6 +846,42 @@ void ima_kexec_cmdline(int kernel_fd, const void *buf, int size) fdput(f); } +/** + * ima_measure_lsm_state - measure LSM specific state + * @lsm_event_name: LSM event + * @buf: pointer to buffer containing LSM specific state + * @size: Number of bytes in buf + * + * Buffers can only be measured, not appraised. + */ +int ima_measure_lsm_state(const char *lsm_event_name, const void *buf, + int size) +{ + if (!lsm_event_name || !buf || !size) + return -EINVAL; + + return process_buffer_measurement(NULL, buf, size, lsm_event_name, + LSM_STATE, 0, NULL); +} + +/** + * ima_measure_lsm_policy - measure LSM specific policy + * @lsm_event_name: LSM event + * @buf: pointer to buffer containing LSM specific policy + * @size: Number of bytes in buf + * + * Buffers can only be measured, not appraised. + */ +int ima_measure_lsm_policy(const char *lsm_event_name, const void *buf, + int size) +{ + if (!lsm_event_name || !buf || !size) + return -EINVAL; + + return process_buffer_measurement(NULL, buf, size, lsm_event_name, + LSM_POLICY, 0, NULL); +} + static int __init init_ima(void) { int error;