From patchwork Wed Dec 9 19:42:05 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tushar Sugandhi X-Patchwork-Id: 11962363 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=-26.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT, USER_IN_DEF_DKIM_WL autolearn=unavailable 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 21DEDC2BB48 for ; Wed, 9 Dec 2020 19:48:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EA8D223D21 for ; Wed, 9 Dec 2020 19:48:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387897AbgLITnF (ORCPT ); Wed, 9 Dec 2020 14:43:05 -0500 Received: from linux.microsoft.com ([13.77.154.182]:47444 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387872AbgLITnF (ORCPT ); Wed, 9 Dec 2020 14:43:05 -0500 Received: from tusharsu-Ubuntu.lan (c-71-197-163-6.hsd1.wa.comcast.net [71.197.163.6]) by linux.microsoft.com (Postfix) with ESMTPSA id A965A20B717B; Wed, 9 Dec 2020 11:42:22 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com A965A20B717B DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1607542943; bh=ZJT7I0jcU6zhnKDsRVETM40HS/KO28i++1zSV50zkX4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nquG7xPklZCFDot5h/UJ4sd6/PvWepDPHrpYcXO2SKtcPxAfeCApTDqDQ2X9Sc+Kn ejqHKs1IgLqr2uSEH9Qknx/XebVOQt+Qz7v/4Y7vcAJUzdrKnkNXZwCBP/261ODYzI oV7NlymwiP2Lc9km2lpHwtTYEovzrspFutd84V68= From: Tushar Sugandhi To: zohar@linux.ibm.com, stephen.smalley.work@gmail.com, casey@schaufler-ca.com, agk@redhat.com, snitzer@redhat.com, gmazyland@gmail.com, paul@paul-moore.com Cc: tyhicks@linux.microsoft.com, sashal@kernel.org, jmorris@namei.org, nramas@linux.microsoft.com, linux-integrity@vger.kernel.org, selinux@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, dm-devel@redhat.com Subject: [PATCH v7 1/8] IMA: generalize keyring specific measurement constructs Date: Wed, 9 Dec 2020 11:42:05 -0800 Message-Id: <20201209194212.5131-2-tusharsu@linux.microsoft.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20201209194212.5131-1-tusharsu@linux.microsoft.com> References: <20201209194212.5131-1-tusharsu@linux.microsoft.com> Precedence: bulk List-ID: IMA functions such as ima_match_keyring(), process_buffer_measurement(), ima_match_policy() etc. handle data specific to keyrings. Currently, these constructs are not generic to handle any func specific data. This makes it harder to extend them without code duplication. Refactor the keyring specific measurement constructs to be generic and reusable in other measurement scenarios. Signed-off-by: Tushar Sugandhi Reviewed-by: Tyler Hicks --- security/integrity/ima/ima.h | 6 ++-- security/integrity/ima/ima_api.c | 6 ++-- security/integrity/ima/ima_main.c | 6 ++-- security/integrity/ima/ima_policy.c | 49 ++++++++++++++++++----------- 4 files changed, 40 insertions(+), 27 deletions(-) diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index 8e8b1e3cb847..e5622ce8cbb1 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -256,7 +256,7 @@ static inline void ima_process_queued_keys(void) {} int ima_get_action(struct inode *inode, const struct cred *cred, u32 secid, int mask, enum ima_hooks func, int *pcr, struct ima_template_desc **template_desc, - const char *keyring); + const char *func_data); int ima_must_measure(struct inode *inode, int mask, enum ima_hooks func); int ima_collect_measurement(struct integrity_iint_cache *iint, struct file *file, void *buf, loff_t size, @@ -268,7 +268,7 @@ void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file, 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 pcr, const char *func_data); void ima_audit_measurement(struct integrity_iint_cache *iint, const unsigned char *filename); int ima_alloc_init_template(struct ima_event_data *event_data, @@ -284,7 +284,7 @@ const char *ima_d_path(const struct path *path, char **pathbuf, char *filename); int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid, enum ima_hooks func, int mask, int flags, int *pcr, struct ima_template_desc **template_desc, - const char *keyring); + const char *func_data); void ima_init_policy(void); void ima_update_policy(void); void ima_update_policy_flag(void); diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c index 4f39fb93f278..af218babd198 100644 --- a/security/integrity/ima/ima_api.c +++ b/security/integrity/ima/ima_api.c @@ -170,7 +170,7 @@ void ima_add_violation(struct file *file, const unsigned char *filename, * @func: caller identifier * @pcr: pointer filled in if matched measure policy sets pcr= * @template_desc: pointer filled in if matched measure policy sets template= - * @keyring: keyring name used to determine the action + * @func_data: private data specific to @func, can be NULL. * * The policy is defined in terms of keypairs: * subj=, obj=, type=, func=, mask=, fsmagic= @@ -186,14 +186,14 @@ void ima_add_violation(struct file *file, const unsigned char *filename, int ima_get_action(struct inode *inode, const struct cred *cred, u32 secid, int mask, enum ima_hooks func, int *pcr, struct ima_template_desc **template_desc, - const char *keyring) + const char *func_data) { int flags = IMA_MEASURE | IMA_AUDIT | IMA_APPRAISE | IMA_HASH; flags &= ima_policy_flag; return ima_match_policy(inode, cred, secid, func, mask, flags, pcr, - template_desc, keyring); + template_desc, func_data); } /* diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index 68956e884403..e76ef4bfd0f4 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -786,13 +786,13 @@ int ima_post_load_data(char *buf, loff_t size, * @eventname: event name to be used for the buffer entry. * @func: IMA hook * @pcr: pcr to extend the measurement - * @keyring: keyring name to determine the action to be performed + * @func_data: private data specific to @func, can be NULL. * * 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 pcr, const char *func_data) { int ret = 0; const char *audit_cause = "ENOMEM"; @@ -831,7 +831,7 @@ void process_buffer_measurement(struct inode *inode, const void *buf, int size, if (func) { security_task_getsecid(current, &secid); action = ima_get_action(inode, current_cred(), secid, 0, func, - &pcr, &template, keyring); + &pcr, &template, func_data); if (!(action & IMA_MEASURE)) return; } diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index 823a0c1379cb..25419c7ff50b 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -453,30 +453,44 @@ int ima_lsm_policy_change(struct notifier_block *nb, unsigned long event, } /** - * ima_match_keyring - determine whether the keyring matches the measure rule - * @rule: a pointer to a rule - * @keyring: name of the keyring to match against the measure rule + * ima_match_rule_data - determine whether the given func_data matches + * the measure rule data + * @rule: IMA policy rule + * @func_data: data to match against the measure rule data * @cred: a pointer to a credentials structure for user validation * - * Returns true if keyring matches one in the rule, false otherwise. + * Returns true if func_data matches one in the rule, false otherwise. */ -static bool ima_match_keyring(struct ima_rule_entry *rule, - const char *keyring, const struct cred *cred) +static bool ima_match_rule_data(struct ima_rule_entry *rule, + const char *func_data, + const struct cred *cred) { + const struct ima_rule_opt_list *opt_list = NULL; bool matched = false; size_t i; if ((rule->flags & IMA_UID) && !rule->uid_op(cred->uid, rule->uid)) return false; - if (!rule->keyrings) - return true; + switch (rule->func) { + case KEY_CHECK: + if (!rule->keyrings) + return true; + else + opt_list = rule->keyrings; + break; + default: + break; + } - if (!keyring) + if (!func_data) + return false; + + if (!opt_list) return false; - for (i = 0; i < rule->keyrings->count; i++) { - if (!strcmp(rule->keyrings->items[i], keyring)) { + for (i = 0; i < opt_list->count; i++) { + if (!strcmp(opt_list->items[i], func_data)) { matched = true; break; } @@ -493,20 +507,20 @@ static bool ima_match_keyring(struct ima_rule_entry *rule, * @secid: the secid of the task to be validated * @func: LIM hook identifier * @mask: requested action (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC) - * @keyring: keyring name to check in policy for KEY_CHECK func + * @func_data: private data specific to @func, can be NULL. * * Returns true on rule match, false on failure. */ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode, const struct cred *cred, u32 secid, enum ima_hooks func, int mask, - const char *keyring) + const char *func_data) { int i; if (func == KEY_CHECK) { return (rule->flags & IMA_FUNC) && (rule->func == func) && - ima_match_keyring(rule, keyring, cred); + ima_match_rule_data(rule, func_data, cred); } if ((rule->flags & IMA_FUNC) && (rule->func != func && func != POST_SETATTR)) @@ -610,8 +624,7 @@ static int get_subaction(struct ima_rule_entry *rule, enum ima_hooks func) * @mask: requested action (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC) * @pcr: set the pcr to extend * @template_desc: the template that should be used for this rule - * @keyring: the keyring name, if given, to be used to check in the policy. - * keyring can be NULL if func is anything other than KEY_CHECK. + * @func_data: private data specific to @func, can be NULL. * * Measure decision based on func/mask/fsmagic and LSM(subj/obj/type) * conditions. @@ -623,7 +636,7 @@ static int get_subaction(struct ima_rule_entry *rule, enum ima_hooks func) int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid, enum ima_hooks func, int mask, int flags, int *pcr, struct ima_template_desc **template_desc, - const char *keyring) + const char *func_data) { struct ima_rule_entry *entry; int action = 0, actmask = flags | (flags << 1); @@ -638,7 +651,7 @@ int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid, continue; if (!ima_match_rules(entry, inode, cred, secid, func, mask, - keyring)) + func_data)) continue; action |= entry->flags & IMA_ACTION_FLAGS; From patchwork Wed Dec 9 19:42:06 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tushar Sugandhi X-Patchwork-Id: 11962355 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=-26.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT, USER_IN_DEF_DKIM_WL autolearn=unavailable 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 DFE66C4361B for ; Wed, 9 Dec 2020 19:47:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A36D823C8F for ; Wed, 9 Dec 2020 19:47:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387859AbgLITnG (ORCPT ); Wed, 9 Dec 2020 14:43:06 -0500 Received: from linux.microsoft.com ([13.77.154.182]:47458 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387873AbgLITnF (ORCPT ); Wed, 9 Dec 2020 14:43:05 -0500 Received: from tusharsu-Ubuntu.lan (c-71-197-163-6.hsd1.wa.comcast.net [71.197.163.6]) by linux.microsoft.com (Postfix) with ESMTPSA id 4500120B7185; Wed, 9 Dec 2020 11:42:23 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 4500120B7185 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1607542943; bh=FiAOsMt7UCZ0dFmGvNg0VcChHJRGlns/OgGkws7fxSw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=iZFm4lvPsjiLnIrXf0HXpkq6PR+zXlC+KJv/sN4rPMJgN3+nC+Q7XAgEKzUvQk1fF Jvnu4VQXiB7Q1rN2BvSlgZNUh3RhGfbakpGyS73763RnBS6tKKtbU1NhMRBcJyxr14 UB/Rcfe15XyBbWd07XLSmTAe3X79XyPBjX/Vcdd4= From: Tushar Sugandhi To: zohar@linux.ibm.com, stephen.smalley.work@gmail.com, casey@schaufler-ca.com, agk@redhat.com, snitzer@redhat.com, gmazyland@gmail.com, paul@paul-moore.com Cc: tyhicks@linux.microsoft.com, sashal@kernel.org, jmorris@namei.org, nramas@linux.microsoft.com, linux-integrity@vger.kernel.org, selinux@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, dm-devel@redhat.com Subject: [PATCH v7 2/8] IMA: add support to measure buffer data hash Date: Wed, 9 Dec 2020 11:42:06 -0800 Message-Id: <20201209194212.5131-3-tusharsu@linux.microsoft.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20201209194212.5131-1-tusharsu@linux.microsoft.com> References: <20201209194212.5131-1-tusharsu@linux.microsoft.com> Precedence: bulk List-ID: The original IMA buffer data measurement sizes were small (e.g. boot command line), but the new buffer data measurement use cases have data sizes that are a lot larger. Just as IMA measures the file data hash, not the file data, IMA should similarly support the option for measuring the hash of the buffer data. Measuring in-memory buffer-data/buffer-data-hash is different than measuring file-data/file-data-hash. For the file, IMA stores the measurements in both measurement log and the file's extended attribute - which can later be used for appraisal as well. For buffer, the measurements are only stored in the IMA log, since the buffer has no extended attributes associated with it. Introduce a boolean parameter measure_buf_hash to support measuring hash of a buffer, which would be much smaller, instead of the buffer itself. Signed-off-by: Tushar Sugandhi --- security/integrity/ima/ima.h | 3 +- security/integrity/ima/ima_appraise.c | 2 +- security/integrity/ima/ima_asymmetric_keys.c | 2 +- security/integrity/ima/ima_main.c | 36 +++++++++++++++++--- security/integrity/ima/ima_queue_keys.c | 3 +- 5 files changed, 38 insertions(+), 8 deletions(-) diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index e5622ce8cbb1..fa3044a7539f 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -268,7 +268,8 @@ void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file, 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 *func_data); + int pcr, const char *func_data, + bool measure_buf_hash); 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_appraise.c b/security/integrity/ima/ima_appraise.c index 8361941ee0a1..46ffa38bab12 100644 --- a/security/integrity/ima/ima_appraise.c +++ b/security/integrity/ima/ima_appraise.c @@ -352,7 +352,7 @@ int ima_check_blacklist(struct integrity_iint_cache *iint, if ((rc == -EPERM) && (iint->flags & IMA_MEASURE)) process_buffer_measurement(NULL, digest, digestsize, "blacklisted-hash", NONE, - pcr, NULL); + pcr, NULL, false); } return rc; diff --git a/security/integrity/ima/ima_asymmetric_keys.c b/security/integrity/ima/ima_asymmetric_keys.c index 1c68c500c26f..a74095793936 100644 --- a/security/integrity/ima/ima_asymmetric_keys.c +++ b/security/integrity/ima/ima_asymmetric_keys.c @@ -60,5 +60,5 @@ void ima_post_key_create_or_update(struct key *keyring, struct key *key, */ process_buffer_measurement(NULL, payload, payload_len, keyring->description, KEY_CHECK, 0, - keyring->description); + keyring->description, false); } diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index e76ef4bfd0f4..03aad13e9e70 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -779,7 +779,7 @@ int ima_post_load_data(char *buf, loff_t size, } /* - * process_buffer_measurement - Measure the buffer to ima log. + * process_buffer_measurement - Measure the buffer or the buffer data hash * @inode: inode associated with the object being measured (NULL for KEY_CHECK) * @buf: pointer to the buffer that needs to be added to the log. * @size: size of buffer(in bytes). @@ -787,12 +787,23 @@ int ima_post_load_data(char *buf, loff_t size, * @func: IMA hook * @pcr: pcr to extend the measurement * @func_data: private data specific to @func, can be NULL. + * @measure_buf_hash: measure buffer hash * - * Based on policy, the buffer is measured into the ima log. + * Measure the buffer into the IMA log, and extend the @pcr. + * + * Determine what buffers are allowed to be measured, based on the policy rules + * and the IMA hook passed using @func. + * + * Use @func_data, if provided, to match against the measurement policy rule + * data for @func. + * + * If @measure_buf_hash is set to true - measure hash of the buffer data, + * else measure the buffer data itself. */ void process_buffer_measurement(struct inode *inode, const void *buf, int size, const char *eventname, enum ima_hooks func, - int pcr, const char *func_data) + int pcr, const char *func_data, + bool measure_buf_hash) { int ret = 0; const char *audit_cause = "ENOMEM"; @@ -807,6 +818,8 @@ void process_buffer_measurement(struct inode *inode, const void *buf, int size, struct ima_digest_data hdr; char digest[IMA_MAX_DIGEST_SIZE]; } hash = {}; + char buf_hash[IMA_MAX_DIGEST_SIZE]; + int buf_hash_len = hash_digest_size[ima_hash_algo]; int violation = 0; int action = 0; u32 secid; @@ -849,6 +862,20 @@ void process_buffer_measurement(struct inode *inode, const void *buf, int size, goto out; } + if (measure_buf_hash) { + memcpy(buf_hash, hash.hdr.digest, buf_hash_len); + + ret = ima_calc_buffer_hash(buf_hash, buf_hash_len, + iint.ima_hash); + if (ret < 0) { + audit_cause = "measure_buf_hash_error"; + goto out; + } + + event_data.buf = buf_hash; + event_data.buf_len = buf_hash_len; + } + ret = ima_alloc_init_template(&event_data, &entry, template); if (ret < 0) { audit_cause = "alloc_entry"; @@ -890,7 +917,8 @@ void ima_kexec_cmdline(int kernel_fd, const void *buf, int size) return; process_buffer_measurement(file_inode(f.file), buf, size, - "kexec-cmdline", KEXEC_CMDLINE, 0, NULL); + "kexec-cmdline", KEXEC_CMDLINE, 0, NULL, + false); fdput(f); } diff --git a/security/integrity/ima/ima_queue_keys.c b/security/integrity/ima/ima_queue_keys.c index 69a8626a35c0..c2f2ad34f9b7 100644 --- a/security/integrity/ima/ima_queue_keys.c +++ b/security/integrity/ima/ima_queue_keys.c @@ -162,7 +162,8 @@ void ima_process_queued_keys(void) entry->payload_len, entry->keyring_name, KEY_CHECK, 0, - entry->keyring_name); + entry->keyring_name, + false); list_del(&entry->list); ima_free_key_entry(entry); } From patchwork Wed Dec 9 19:42:07 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tushar Sugandhi X-Patchwork-Id: 11962359 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=-26.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT, USER_IN_DEF_DKIM_WL autolearn=unavailable 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 958E9C2BBD4 for ; Wed, 9 Dec 2020 19:48:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4E8A923CD2 for ; Wed, 9 Dec 2020 19:48:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388105AbgLITrF (ORCPT ); Wed, 9 Dec 2020 14:47:05 -0500 Received: from linux.microsoft.com ([13.77.154.182]:47476 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387878AbgLITnG (ORCPT ); Wed, 9 Dec 2020 14:43:06 -0500 Received: from tusharsu-Ubuntu.lan (c-71-197-163-6.hsd1.wa.comcast.net [71.197.163.6]) by linux.microsoft.com (Postfix) with ESMTPSA id F40A620B7187; Wed, 9 Dec 2020 11:42:23 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com F40A620B7187 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1607542944; bh=LMWnZCiY5cIy755ozh0nv0ZfFVIOc+VpzHbc2Bru8eg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=X+DZsKu0vi8vkKKXH+CH+0qc6r6uN7UcEE8N7i9U/L4XKXoVLja0+kRyR1MUHvsji UQSlmIAMBosDI9CE58BW31jqI0A+lvzw8k63fVYLih9oax8T+4k5BsHl693y9ratxt 5wlHfJGIgDKriT+C6DsQzC+kgqTDHyaUrPl8VzMs= From: Tushar Sugandhi To: zohar@linux.ibm.com, stephen.smalley.work@gmail.com, casey@schaufler-ca.com, agk@redhat.com, snitzer@redhat.com, gmazyland@gmail.com, paul@paul-moore.com Cc: tyhicks@linux.microsoft.com, sashal@kernel.org, jmorris@namei.org, nramas@linux.microsoft.com, linux-integrity@vger.kernel.org, selinux@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, dm-devel@redhat.com Subject: [PATCH v7 3/8] IMA: define a hook to measure kernel integrity critical data Date: Wed, 9 Dec 2020 11:42:07 -0800 Message-Id: <20201209194212.5131-4-tusharsu@linux.microsoft.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20201209194212.5131-1-tusharsu@linux.microsoft.com> References: <20201209194212.5131-1-tusharsu@linux.microsoft.com> Precedence: bulk List-ID: IMA provides capabilities to measure file data, and in-memory buffer data. However, various data structures, policies, and states stored in kernel memory also impact the integrity of the system. Several kernel subsystems contain such integrity critical data. These kernel subsystems help protect the integrity of a device. Currently, IMA does not provide a generic function for kernel subsystems to measure their integrity critical data. Define a new IMA hook - ima_measure_critical_data to measure kernel integrity critical data. Signed-off-by: Tushar Sugandhi --- Documentation/ABI/testing/ima_policy | 2 +- include/linux/ima.h | 6 +++++ security/integrity/ima/ima.h | 1 + security/integrity/ima/ima_api.c | 2 +- security/integrity/ima/ima_main.c | 36 ++++++++++++++++++++++++++++ security/integrity/ima/ima_policy.c | 2 ++ 6 files changed, 47 insertions(+), 2 deletions(-) diff --git a/Documentation/ABI/testing/ima_policy b/Documentation/ABI/testing/ima_policy index e35263f97fc1..6ec7daa87cba 100644 --- a/Documentation/ABI/testing/ima_policy +++ b/Documentation/ABI/testing/ima_policy @@ -32,7 +32,7 @@ Description: func:= [BPRM_CHECK][MMAP_CHECK][CREDS_CHECK][FILE_CHECK]MODULE_CHECK] [FIRMWARE_CHECK] [KEXEC_KERNEL_CHECK] [KEXEC_INITRAMFS_CHECK] - [KEXEC_CMDLINE] [KEY_CHECK] + [KEXEC_CMDLINE] [KEY_CHECK] [CRITICAL_DATA] mask:= [[^]MAY_READ] [[^]MAY_WRITE] [[^]MAY_APPEND] [[^]MAY_EXEC] fsmagic:= hex value diff --git a/include/linux/ima.h b/include/linux/ima.h index ac3d82f962f2..675f54db6264 100644 --- a/include/linux/ima.h +++ b/include/linux/ima.h @@ -30,6 +30,9 @@ 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 void ima_measure_critical_data(const char *event_name, + const void *buf, int buf_len, + bool measure_buf_hash); #ifdef CONFIG_IMA_APPRAISE_BOOTPARAM extern void ima_appraise_parse_cmdline(void); @@ -122,6 +125,9 @@ 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 void ima_measure_critical_data(const char *event_name, + const void *buf, int buf_len, + bool measure_buf_hash) {} #endif /* CONFIG_IMA */ #ifndef CONFIG_IMA_KEXEC diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index fa3044a7539f..7d9deda6a8b3 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -201,6 +201,7 @@ static inline unsigned int ima_hash_key(u8 *digest) hook(POLICY_CHECK, policy) \ hook(KEXEC_CMDLINE, kexec_cmdline) \ hook(KEY_CHECK, key) \ + hook(CRITICAL_DATA, critical_data) \ hook(MAX_CHECK, none) #define __ima_hook_enumify(ENUM, str) ENUM, diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c index af218babd198..9917e1730cb6 100644 --- a/security/integrity/ima/ima_api.c +++ b/security/integrity/ima/ima_api.c @@ -176,7 +176,7 @@ void ima_add_violation(struct file *file, const unsigned char *filename, * subj=, obj=, type=, func=, mask=, fsmagic= * subj,obj, and type: are LSM specific. * func: FILE_CHECK | BPRM_CHECK | CREDS_CHECK | MMAP_CHECK | MODULE_CHECK - * | KEXEC_CMDLINE | KEY_CHECK + * | KEXEC_CMDLINE | KEY_CHECK | CRITICAL_DATA * mask: contains the permission mask * fsmagic: hex value * diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index 03aad13e9e70..ae59f4a4dd70 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -922,6 +922,42 @@ void ima_kexec_cmdline(int kernel_fd, const void *buf, int size) fdput(f); } +/** + * ima_measure_critical_data - measure kernel integrity critical data + * @event_name: event name to be used for the buffer entry + * @buf: pointer to buffer containing data to measure + * @buf_len: length of buffer(in bytes) + * @measure_buf_hash: measure buffer hash + * + * Measure the kernel subsystem data, critical to the integrity of the kernel, + * into the IMA log and extend the @pcr. + * + * Use @event_name to describe the state/buffer data change. + * Examples of critical data (buf) could be kernel in-memory r/o structures, + * hash of the memory structures, or data that represents subsystem state + * change. + * + * If @measure_buf_hash is set to true - measure hash of the buffer data, + * else measure the buffer data itself. + * measure_buf_hash can be used to save space, if the data being measured + * is too large. + * + * The data (buf) can only be measured, not appraised. + */ +void ima_measure_critical_data(const char *event_name, + const void *buf, int buf_len, + bool measure_buf_hash) +{ + if (!event_name || !buf || !buf_len) { + pr_err("Invalid arguments passed to %s().\n", __func__); + return; + } + + process_buffer_measurement(NULL, buf, buf_len, event_name, + CRITICAL_DATA, 0, NULL, + measure_buf_hash); +} + static int __init init_ima(void) { int error; diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index 25419c7ff50b..2a0c0603626e 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -1251,6 +1251,8 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry) else if (IS_ENABLED(CONFIG_IMA_MEASURE_ASYMMETRIC_KEYS) && strcmp(args[0].from, "KEY_CHECK") == 0) entry->func = KEY_CHECK; + else if (strcmp(args[0].from, "CRITICAL_DATA") == 0) + entry->func = CRITICAL_DATA; else result = -EINVAL; if (!result) From patchwork Wed Dec 9 19:42:08 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tushar Sugandhi X-Patchwork-Id: 11962361 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=-26.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT, USER_IN_DEF_DKIM_WL autolearn=unavailable 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 A163BC4361B for ; Wed, 9 Dec 2020 19:48:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6643023C8F for ; Wed, 9 Dec 2020 19:48:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387991AbgLITrE (ORCPT ); Wed, 9 Dec 2020 14:47:04 -0500 Received: from linux.microsoft.com ([13.77.154.182]:47492 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387857AbgLITnG (ORCPT ); Wed, 9 Dec 2020 14:43:06 -0500 Received: from tusharsu-Ubuntu.lan (c-71-197-163-6.hsd1.wa.comcast.net [71.197.163.6]) by linux.microsoft.com (Postfix) with ESMTPSA id A6EB720B7189; Wed, 9 Dec 2020 11:42:24 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com A6EB720B7189 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1607542945; bh=13W9y/glUb8I3SzOqOuxO+1MJwZs/tFHH0a5DtYqn+g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TZVpGynKEEZSZfv4sGpjoXpRov6wDOKUZe6Bk2s0M7IyWfEjL11cvBW/RiftHz9k1 8vI8zRWmbI63YTH0/dTkHJXgwqs1bxLGX1+6La9EI/+jASChz6i/LT+0FX+9tNXTrX ACemq6NpMQLBt4kUsRNpMutGXMRsw7tTv2AaleWY= From: Tushar Sugandhi To: zohar@linux.ibm.com, stephen.smalley.work@gmail.com, casey@schaufler-ca.com, agk@redhat.com, snitzer@redhat.com, gmazyland@gmail.com, paul@paul-moore.com Cc: tyhicks@linux.microsoft.com, sashal@kernel.org, jmorris@namei.org, nramas@linux.microsoft.com, linux-integrity@vger.kernel.org, selinux@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, dm-devel@redhat.com Subject: [PATCH v7 4/8] IMA: add policy rule to measure critical data Date: Wed, 9 Dec 2020 11:42:08 -0800 Message-Id: <20201209194212.5131-5-tusharsu@linux.microsoft.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20201209194212.5131-1-tusharsu@linux.microsoft.com> References: <20201209194212.5131-1-tusharsu@linux.microsoft.com> Precedence: bulk List-ID: A new IMA policy rule is needed for the IMA hook ima_measure_critical_data() and the corresponding func CRITICAL_DATA for measuring the input buffer. The policy rule should ensure the buffer would get measured only when the policy rule allows the action. The policy rule should also support the necessary constraints (flags etc.) for integrity critical buffer data measurements. Add a policy rule to define the constraints for restricting integrity critical data measurements. Signed-off-by: Tushar Sugandhi --- security/integrity/ima/ima_policy.c | 35 +++++++++++++++++++++++++---- 1 file changed, 31 insertions(+), 4 deletions(-) diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index 2a0c0603626e..9a8ee80a3128 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -34,6 +34,7 @@ #define IMA_PCR 0x0100 #define IMA_FSNAME 0x0200 #define IMA_KEYRINGS 0x0400 +#define IMA_DATA_SOURCE 0x0800 #define UNKNOWN 0 #define MEASURE 0x0001 /* same as IMA_MEASURE */ @@ -85,6 +86,7 @@ struct ima_rule_entry { } lsm[MAX_LSM_RULES]; char *fsname; struct ima_rule_opt_list *keyrings; /* Measure keys added to these keyrings */ + struct ima_rule_opt_list *data_source; /* Measure data from this source */ struct ima_template_desc *template; }; @@ -479,6 +481,12 @@ static bool ima_match_rule_data(struct ima_rule_entry *rule, else opt_list = rule->keyrings; break; + case CRITICAL_DATA: + if (!rule->data_source) + return true; + else + opt_list = rule->data_source; + break; default: break; } @@ -518,13 +526,19 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode, { int i; - if (func == KEY_CHECK) { - return (rule->flags & IMA_FUNC) && (rule->func == func) && - ima_match_rule_data(rule, func_data, cred); - } if ((rule->flags & IMA_FUNC) && (rule->func != func && func != POST_SETATTR)) return false; + + switch (func) { + case KEY_CHECK: + case CRITICAL_DATA: + return ((rule->func == func) && + ima_match_rule_data(rule, func_data, cred)); + default: + break; + } + if ((rule->flags & IMA_MASK) && (rule->mask != mask && func != POST_SETATTR)) return false; @@ -1119,6 +1133,19 @@ static bool ima_validate_rule(struct ima_rule_entry *entry) if (ima_rule_contains_lsm_cond(entry)) return false; + break; + case CRITICAL_DATA: + if (entry->action & ~(MEASURE | DONT_MEASURE)) + return false; + + if (!(entry->flags & IMA_DATA_SOURCE) || + (entry->flags & ~(IMA_FUNC | IMA_UID | IMA_PCR | + IMA_DATA_SOURCE))) + return false; + + if (ima_rule_contains_lsm_cond(entry)) + return false; + break; default: return false; From patchwork Wed Dec 9 19:42:09 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tushar Sugandhi X-Patchwork-Id: 11962329 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=-26.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT, USER_IN_DEF_DKIM_WL autolearn=unavailable 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 31C97C4167B for ; Wed, 9 Dec 2020 19:45:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F1DCD23C8F for ; Wed, 9 Dec 2020 19:45:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387843AbgLITnt (ORCPT ); Wed, 9 Dec 2020 14:43:49 -0500 Received: from linux.microsoft.com ([13.77.154.182]:47630 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387839AbgLITnq (ORCPT ); Wed, 9 Dec 2020 14:43:46 -0500 Received: from tusharsu-Ubuntu.lan (c-71-197-163-6.hsd1.wa.comcast.net [71.197.163.6]) by linux.microsoft.com (Postfix) with ESMTPSA id 63C8420B718A; Wed, 9 Dec 2020 11:42:25 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 63C8420B718A DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1607542945; bh=bzuU81mo+/j5mNSRtkpRgP9nYoQTmrBcFrpkU3iE3ic=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pCjeKE1fNFwsNAHAmuZljsUTb383ZrRhoNT2NkT0DLtcfKkRLl/DmwpZWo9LvNPIS yXhMfNUvsjvhkquZbGZ4eZ05FX476WF4f4yVNY+GYbK5kFfuUtzAYYY0ALu5Ll5r4W TMEPWp4as7YNEEp0B2rXoAJ51EmwLmWFJ9yYRtjM= From: Tushar Sugandhi To: zohar@linux.ibm.com, stephen.smalley.work@gmail.com, casey@schaufler-ca.com, agk@redhat.com, snitzer@redhat.com, gmazyland@gmail.com, paul@paul-moore.com Cc: tyhicks@linux.microsoft.com, sashal@kernel.org, jmorris@namei.org, nramas@linux.microsoft.com, linux-integrity@vger.kernel.org, selinux@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, dm-devel@redhat.com Subject: [PATCH v7 5/8] IMA: limit critical data measurement based on a label Date: Wed, 9 Dec 2020 11:42:09 -0800 Message-Id: <20201209194212.5131-6-tusharsu@linux.microsoft.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20201209194212.5131-1-tusharsu@linux.microsoft.com> References: <20201209194212.5131-1-tusharsu@linux.microsoft.com> Precedence: bulk List-ID: System administrators should be able to limit which kernel subsystems they want to measure the critical data for. To enable that, an IMA policy condition to choose specific kernel subsystems is needed. This policy condition would constrain the measurement of the critical data based on a label for the given subsystems. Add a new IMA policy condition - "data_source:=" to the IMA func CRITICAL_DATA to allow measurement of various kernel subsystems. This policy condition would enable the system administrators to restrict the measurement to the labels listed in "data_source:=". Limit the measurement to the labels that are specified in the IMA policy - CRITICAL_DATA+"data_source:=". If "data_sources:=" is not provided with the func CRITICAL_DATA, the data from all the supported kernel subsystems is measured. Signed-off-by: Tushar Sugandhi --- Documentation/ABI/testing/ima_policy | 2 ++ security/integrity/ima/ima_policy.c | 26 +++++++++++++++++++++++++- 2 files changed, 27 insertions(+), 1 deletion(-) diff --git a/Documentation/ABI/testing/ima_policy b/Documentation/ABI/testing/ima_policy index 6ec7daa87cba..0f4ee9e0a455 100644 --- a/Documentation/ABI/testing/ima_policy +++ b/Documentation/ABI/testing/ima_policy @@ -52,6 +52,8 @@ Description: template:= name of a defined IMA template type (eg, ima-ng). Only valid when action is "measure". pcr:= decimal value + data_source:= [label] + label:= a unique string used for grouping and limiting critical data. default policy: # PROC_SUPER_MAGIC diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index 9a8ee80a3128..7486d09a3f60 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -934,7 +934,7 @@ enum { Opt_uid_lt, Opt_euid_lt, Opt_fowner_lt, Opt_appraise_type, Opt_appraise_flag, Opt_permit_directio, Opt_pcr, Opt_template, Opt_keyrings, - Opt_err + Opt_data_source, Opt_err }; static const match_table_t policy_tokens = { @@ -971,6 +971,7 @@ static const match_table_t policy_tokens = { {Opt_pcr, "pcr=%s"}, {Opt_template, "template=%s"}, {Opt_keyrings, "keyrings=%s"}, + {Opt_data_source, "data_source=%s"}, {Opt_err, NULL} }; @@ -1350,6 +1351,23 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry) entry->flags |= IMA_KEYRINGS; break; + case Opt_data_source: + ima_log_string(ab, "data_source", args[0].from); + + if (entry->data_source) { + result = -EINVAL; + break; + } + + entry->data_source = ima_alloc_rule_opt_list(args); + if (IS_ERR(entry->data_source)) { + result = PTR_ERR(entry->data_source); + entry->data_source = NULL; + break; + } + + entry->flags |= IMA_DATA_SOURCE; + break; case Opt_fsuuid: ima_log_string(ab, "fsuuid", args[0].from); @@ -1730,6 +1748,12 @@ int ima_policy_show(struct seq_file *m, void *v) seq_puts(m, " "); } + if (entry->flags & IMA_DATA_SOURCE) { + seq_puts(m, "data_source="); + ima_show_rule_opt_list(m, entry->data_source); + seq_puts(m, " "); + } + if (entry->flags & IMA_PCR) { snprintf(tbuf, sizeof(tbuf), "%d", entry->pcr); seq_printf(m, pt(Opt_pcr), tbuf); From patchwork Wed Dec 9 19:42:10 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tushar Sugandhi X-Patchwork-Id: 11962325 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=-26.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,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 6517CC433FE for ; Wed, 9 Dec 2020 19:44:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1F61623BC6 for ; Wed, 9 Dec 2020 19:44:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387940AbgLITnz (ORCPT ); Wed, 9 Dec 2020 14:43:55 -0500 Received: from linux.microsoft.com ([13.77.154.182]:47628 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387840AbgLITnp (ORCPT ); Wed, 9 Dec 2020 14:43:45 -0500 Received: from tusharsu-Ubuntu.lan (c-71-197-163-6.hsd1.wa.comcast.net [71.197.163.6]) by linux.microsoft.com (Postfix) with ESMTPSA id 0904320B718B; Wed, 9 Dec 2020 11:42:26 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 0904320B718B DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1607542946; bh=a5f+ij0E0tDSy+bJfyUc0/IK+DK1TBFrlmTbWMu4t+0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FD3vrDkDlo6QTkWauiE9QzwtM+mluPQ6yhVNFD7T9OU9ijug1v0jKhU5B8IENxgZK e4Yg5U8HpJnQtE/yaVj3LmJ44f4giK57g87WSXqoqjcr2evPDuAr4Utmy7yLFx7JC4 Rpzd0ypeZLHaLdR6SdaprLtBjpSLXIN8Qo326gNQ= From: Tushar Sugandhi To: zohar@linux.ibm.com, stephen.smalley.work@gmail.com, casey@schaufler-ca.com, agk@redhat.com, snitzer@redhat.com, gmazyland@gmail.com, paul@paul-moore.com Cc: tyhicks@linux.microsoft.com, sashal@kernel.org, jmorris@namei.org, nramas@linux.microsoft.com, linux-integrity@vger.kernel.org, selinux@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, dm-devel@redhat.com Subject: [PATCH v7 6/8] IMA: extend critical data hook to limit the measurement based on a label Date: Wed, 9 Dec 2020 11:42:10 -0800 Message-Id: <20201209194212.5131-7-tusharsu@linux.microsoft.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20201209194212.5131-1-tusharsu@linux.microsoft.com> References: <20201209194212.5131-1-tusharsu@linux.microsoft.com> Precedence: bulk List-ID: The IMA hook ima_measure_critical_data() does not support a way to specify the source of the critical data provider. Thus, the data measurement cannot be constrained based on the data source label in the IMA policy. Extend the IMA hook ima_measure_critical_data() to support passing the data source label as an input parameter, so that the policy rule can be used to limit the measurements based on the label. Signed-off-by: Tushar Sugandhi Reviewed-by: Tyler Hicks --- include/linux/ima.h | 6 ++++-- security/integrity/ima/ima_main.c | 11 ++++++++--- 2 files changed, 12 insertions(+), 5 deletions(-) diff --git a/include/linux/ima.h b/include/linux/ima.h index 675f54db6264..6434287a81cd 100644 --- a/include/linux/ima.h +++ b/include/linux/ima.h @@ -30,7 +30,8 @@ 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 void ima_measure_critical_data(const char *event_name, +extern void ima_measure_critical_data(const char *event_data_source, + const char *event_name, const void *buf, int buf_len, bool measure_buf_hash); @@ -125,7 +126,8 @@ 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 void ima_measure_critical_data(const char *event_name, +static inline void ima_measure_critical_data(const char *event_data_source, + const char *event_name, const void *buf, int buf_len, bool measure_buf_hash) {} #endif /* CONFIG_IMA */ diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index ae59f4a4dd70..7c633901f441 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -924,6 +924,7 @@ void ima_kexec_cmdline(int kernel_fd, const void *buf, int size) /** * ima_measure_critical_data - measure kernel integrity critical data + * @event_data_source: kernel data source being measured * @event_name: event name to be used for the buffer entry * @buf: pointer to buffer containing data to measure * @buf_len: length of buffer(in bytes) @@ -932,6 +933,9 @@ void ima_kexec_cmdline(int kernel_fd, const void *buf, int size) * Measure the kernel subsystem data, critical to the integrity of the kernel, * into the IMA log and extend the @pcr. * + * Use @event_data_source to describe the kernel data source for the buffer + * being measured. + * * Use @event_name to describe the state/buffer data change. * Examples of critical data (buf) could be kernel in-memory r/o structures, * hash of the memory structures, or data that represents subsystem state @@ -944,17 +948,18 @@ void ima_kexec_cmdline(int kernel_fd, const void *buf, int size) * * The data (buf) can only be measured, not appraised. */ -void ima_measure_critical_data(const char *event_name, +void ima_measure_critical_data(const char *event_data_source, + const char *event_name, const void *buf, int buf_len, bool measure_buf_hash) { - if (!event_name || !buf || !buf_len) { + if (!event_name || !event_data_source || !buf || !buf_len) { pr_err("Invalid arguments passed to %s().\n", __func__); return; } process_buffer_measurement(NULL, buf, buf_len, event_name, - CRITICAL_DATA, 0, NULL, + CRITICAL_DATA, 0, event_data_source, measure_buf_hash); } From patchwork Wed Dec 9 19:42:11 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tushar Sugandhi X-Patchwork-Id: 11962327 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=-23.4 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, UNWANTED_LANGUAGE_BODY,USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=unavailable 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 56342C4361B for ; Wed, 9 Dec 2020 19:45:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3028123C8F for ; Wed, 9 Dec 2020 19:45:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387931AbgLITnt (ORCPT ); Wed, 9 Dec 2020 14:43:49 -0500 Received: from linux.microsoft.com ([13.77.154.182]:47634 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387841AbgLITnq (ORCPT ); Wed, 9 Dec 2020 14:43:46 -0500 Received: from tusharsu-Ubuntu.lan (c-71-197-163-6.hsd1.wa.comcast.net [71.197.163.6]) by linux.microsoft.com (Postfix) with ESMTPSA id B45B520B718C; Wed, 9 Dec 2020 11:42:26 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com B45B520B718C DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1607542947; bh=Z+MLUnGUSj9sbDiLucraPrqMvEgj5sPtWl/C1X0EQ1A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=aKlJtq7Mm6PWfFLQiRD83zh6aKhrLsi5VRoKOIa/FEZu+At/JXWcD7HoTXkLXIrVq d2vTKPcRaFjTYtp0mYHMp3gQvpaGZ9ygwO4e/wpg9W8rGcAGF07zFsqmGv4opR55MV MLpnX5q6x9XckxuMqK7PAKzPxGlRjY/R6AYJg5Pc= From: Tushar Sugandhi To: zohar@linux.ibm.com, stephen.smalley.work@gmail.com, casey@schaufler-ca.com, agk@redhat.com, snitzer@redhat.com, gmazyland@gmail.com, paul@paul-moore.com Cc: tyhicks@linux.microsoft.com, sashal@kernel.org, jmorris@namei.org, nramas@linux.microsoft.com, linux-integrity@vger.kernel.org, selinux@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, dm-devel@redhat.com Subject: [PATCH v7 7/8] IMA: define a builtin critical data measurement policy Date: Wed, 9 Dec 2020 11:42:11 -0800 Message-Id: <20201209194212.5131-8-tusharsu@linux.microsoft.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20201209194212.5131-1-tusharsu@linux.microsoft.com> References: <20201209194212.5131-1-tusharsu@linux.microsoft.com> Precedence: bulk List-ID: From: Lakshmi Ramasubramanian Define a new critical data builtin policy to allow measuring early kernel integrity critical data before a custom IMA policy is loaded. Add critical data to built-in IMA rules if the kernel command line contains "ima_policy=critical_data". Update the documentation on kernel parameters to document the new critical data builtin policy. Signed-off-by: Lakshmi Ramasubramanian Reviewed-by: Tyler Hicks --- Documentation/admin-guide/kernel-parameters.txt | 5 ++++- security/integrity/ima/ima_policy.c | 12 ++++++++++++ 2 files changed, 16 insertions(+), 1 deletion(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 526d65d8573a..6034d75c3ca0 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1746,7 +1746,7 @@ ima_policy= [IMA] The builtin policies to load during IMA setup. Format: "tcb | appraise_tcb | secure_boot | - fail_securely" + fail_securely | critical_data" The "tcb" policy measures all programs exec'd, files mmap'd for exec, and all files opened with the read @@ -1765,6 +1765,9 @@ filesystems with the SB_I_UNVERIFIABLE_SIGNATURE flag. + The "critical_data" policy measures kernel integrity + critical data. + ima_tcb [IMA] Deprecated. Use ima_policy= instead. Load a policy which meets the needs of the Trusted Computing Base. This means IMA will measure all diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index 7486d09a3f60..37ca16a9e65f 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -206,6 +206,10 @@ static struct ima_rule_entry secure_boot_rules[] __ro_after_init = { .flags = IMA_FUNC | IMA_DIGSIG_REQUIRED}, }; +static struct ima_rule_entry critical_data_rules[] __ro_after_init = { + {.action = MEASURE, .func = CRITICAL_DATA, .flags = IMA_FUNC}, +}; + /* An array of architecture specific rules */ static struct ima_rule_entry *arch_policy_entry __ro_after_init; @@ -228,6 +232,7 @@ __setup("ima_tcb", default_measure_policy_setup); static bool ima_use_appraise_tcb __initdata; static bool ima_use_secure_boot __initdata; +static bool ima_use_critical_data __initdata; static bool ima_fail_unverifiable_sigs __ro_after_init; static int __init policy_setup(char *str) { @@ -242,6 +247,8 @@ static int __init policy_setup(char *str) ima_use_appraise_tcb = true; else if (strcmp(p, "secure_boot") == 0) ima_use_secure_boot = true; + else if (strcmp(p, "critical_data") == 0) + ima_use_critical_data = true; else if (strcmp(p, "fail_securely") == 0) ima_fail_unverifiable_sigs = true; else @@ -875,6 +882,11 @@ void __init ima_init_policy(void) ARRAY_SIZE(default_appraise_rules), IMA_DEFAULT_POLICY); + if (ima_use_critical_data) + add_rules(critical_data_rules, + ARRAY_SIZE(critical_data_rules), + IMA_DEFAULT_POLICY); + ima_update_policy_flag(); } From patchwork Wed Dec 9 19:42:12 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tushar Sugandhi X-Patchwork-Id: 11962357 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=-26.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT, USER_IN_DEF_DKIM_WL autolearn=unavailable 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 9935DC433FE for ; Wed, 9 Dec 2020 19:48:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5BD3D23BC6 for ; Wed, 9 Dec 2020 19:48:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387935AbgLITnt (ORCPT ); Wed, 9 Dec 2020 14:43:49 -0500 Received: from linux.microsoft.com ([13.77.154.182]:47632 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387842AbgLITnr (ORCPT ); Wed, 9 Dec 2020 14:43:47 -0500 Received: from tusharsu-Ubuntu.lan (c-71-197-163-6.hsd1.wa.comcast.net [71.197.163.6]) by linux.microsoft.com (Postfix) with ESMTPSA id 7501920B7194; Wed, 9 Dec 2020 11:42:27 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 7501920B7194 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1607542948; bh=r6UFZBTDrV2iEH3yTe/6e5c6NTxX2JHze2uNFVDqmIg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TYQ35BpAEWBUG0VG+TxRmAMmXH0XCwo1MKPOUygnwtc1IMloCuA8Yyc7GZWE4Yxd7 HsutZkF5MvwXXHjzXPDgK03/eBRHGFyfDUwsgGYes8XP1IWp9fxYMp5s/mTzPrzIXk m0aZL96tD8JI0J4jEG0mV0ZDPPf/28CyuZE0N/7g= From: Tushar Sugandhi To: zohar@linux.ibm.com, stephen.smalley.work@gmail.com, casey@schaufler-ca.com, agk@redhat.com, snitzer@redhat.com, gmazyland@gmail.com, paul@paul-moore.com Cc: tyhicks@linux.microsoft.com, sashal@kernel.org, jmorris@namei.org, nramas@linux.microsoft.com, linux-integrity@vger.kernel.org, selinux@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, dm-devel@redhat.com Subject: [PATCH v7 8/8] selinux: include a consumer of the new IMA critical data hook Date: Wed, 9 Dec 2020 11:42:12 -0800 Message-Id: <20201209194212.5131-9-tusharsu@linux.microsoft.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20201209194212.5131-1-tusharsu@linux.microsoft.com> References: <20201209194212.5131-1-tusharsu@linux.microsoft.com> Precedence: bulk List-ID: From: Lakshmi Ramasubramanian IMA measures files and buffer data such as keys, command line arguments passed to the kernel on kexec system call, etc. While these measurements enable monitoring and validating the integrity of the system, it is not sufficient. Various data structures, policies and states stored in kernel memory also impact the integrity of the system. Updates to these data structures would have an impact on the security functionalities. For example, SELinux stores the active policy in memory. Changes to this data at runtime would have an impact on the security guarantees provided by SELinux. Measuring such in-memory data structures through IMA subsystem provides a secure way for a remote attestation service to know the state of the system and also the runtime changes in the state of the system. SELinux policy is a critical data for this security module that needs to be measured. This measurement can be used by an attestation service, for instance, to verify if the policy has been setup correctly and that it hasn't been tampered at run-time. Measure the hash of the loaded policy by calling the IMA hook ima_measure_critical_data(). Since the size of the loaded policy can be large (several MB), measure the hash of the policy instead of the entire policy to avoid bloating the IMA log entry. Add "selinux" to the list of supported data sources maintained by IMA to enable measuring SELinux data. To enable SELinux data measurement, the following steps are required: 1, Add "ima_policy=critical_data" to the kernel command line arguments to enable measuring SELinux data at boot time. For example, BOOT_IMAGE=/boot/vmlinuz-5.10.0-rc1+ root=UUID=fd643309-a5d2-4ed3-b10d-3c579a5fab2f ro nomodeset security=selinux ima_policy=critical_data 2, Add the following rule to /etc/ima/ima-policy measure func=CRITICAL_DATA data_source=selinux Sample measurement of the hash of SELinux policy: To verify the measured data with the current SELinux policy run the following commands and verify the output hash values match. sha256sum /sys/fs/selinux/policy | cut -d' ' -f 1 grep "selinux-policy-hash" /sys/kernel/security/integrity/ima/ascii_runtime_measurements | tail -1 | cut -d' ' -f 6 Note that the actual verification of SELinux policy would require loading the expected policy into an identical kernel on a pristine/known-safe system and run the sha256sum /sys/kernel/selinux/policy there to get the expected hash. Signed-off-by: Lakshmi Ramasubramanian Suggested-by: Stephen Smalley --- Documentation/ABI/testing/ima_policy | 3 +- security/selinux/Makefile | 2 + security/selinux/include/security.h | 11 +++- security/selinux/measure.c | 86 ++++++++++++++++++++++++++++ security/selinux/ss/services.c | 71 ++++++++++++++++++++--- 5 files changed, 162 insertions(+), 11 deletions(-) create mode 100644 security/selinux/measure.c diff --git a/Documentation/ABI/testing/ima_policy b/Documentation/ABI/testing/ima_policy index 0f4ee9e0a455..7c7023f7986b 100644 --- a/Documentation/ABI/testing/ima_policy +++ b/Documentation/ABI/testing/ima_policy @@ -52,8 +52,9 @@ Description: template:= name of a defined IMA template type (eg, ima-ng). Only valid when action is "measure". pcr:= decimal value - data_source:= [label] + data_source:= [selinux]|[label] label:= a unique string used for grouping and limiting critical data. + For example, "selinux" to measure critical data for SELinux. default policy: # PROC_SUPER_MAGIC diff --git a/security/selinux/Makefile b/security/selinux/Makefile index 4d8e0e8adf0b..83d512116341 100644 --- a/security/selinux/Makefile +++ b/security/selinux/Makefile @@ -16,6 +16,8 @@ selinux-$(CONFIG_NETLABEL) += netlabel.o selinux-$(CONFIG_SECURITY_INFINIBAND) += ibpkey.o +selinux-$(CONFIG_IMA) += measure.o + ccflags-y := -I$(srctree)/security/selinux -I$(srctree)/security/selinux/include $(addprefix $(obj)/,$(selinux-y)): $(obj)/flask.h diff --git a/security/selinux/include/security.h b/security/selinux/include/security.h index 3cc8bab31ea8..18ee65c98446 100644 --- a/security/selinux/include/security.h +++ b/security/selinux/include/security.h @@ -229,7 +229,8 @@ void selinux_policy_cancel(struct selinux_state *state, struct selinux_policy *policy); int security_read_policy(struct selinux_state *state, void **data, size_t *len); - +int security_read_policy_kernel(struct selinux_state *state, + void **data, size_t *len); int security_policycap_supported(struct selinux_state *state, unsigned int req_cap); @@ -446,4 +447,12 @@ extern void ebitmap_cache_init(void); extern void hashtab_cache_init(void); extern int security_sidtab_hash_stats(struct selinux_state *state, char *page); +#ifdef CONFIG_IMA +extern void selinux_measure_state(struct selinux_state *selinux_state); +#else +static inline void selinux_measure_state(struct selinux_state *selinux_state) +{ +} +#endif + #endif /* _SELINUX_SECURITY_H_ */ diff --git a/security/selinux/measure.c b/security/selinux/measure.c new file mode 100644 index 000000000000..c409ada6ea39 --- /dev/null +++ b/security/selinux/measure.c @@ -0,0 +1,86 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Measure SELinux state using IMA subsystem. + */ +#include +#include +#include +#include "security.h" + +/* + * This function creates a unique name by appending the timestamp to + * the given string. This string is passed as "event_name" to the IMA + * hook to measure the given SELinux data. + * + * The data provided by SELinux to the IMA subsystem for measuring may have + * already been measured (for instance the same state existed earlier). + * But for SELinux the current data represents a state change and hence + * needs to be measured again. To enable this, pass a unique "event_name" + * to the IMA hook so that IMA subsystem will always measure the given data. + * + * For example, + * At time T0 SELinux data to be measured is "foo". IMA measures it. + * At time T1 the data is changed to "bar". IMA measures it. + * At time T2 the data is changed to "foo" again. IMA will not measure it + * (since it was already measured) unless the event_name, for instance, + * is different in this call. + */ +static char *selinux_event_name(const char *name_prefix) +{ + char *event_name = NULL; + struct timespec64 cur_time; + + ktime_get_real_ts64(&cur_time); + event_name = kasprintf(GFP_KERNEL, "%s-%lld:%09ld", name_prefix, + cur_time.tv_sec, cur_time.tv_nsec); + if (!event_name) { + pr_err("%s: event name not allocated.\n", __func__); + return NULL; + } + + return event_name; +} + +/* + * selinux_measure_state - Measure hash of the SELinux policy + * + * @state: selinux state struct + * + * NOTE: This function must be called with policy_mutex held. + */ +void selinux_measure_state(struct selinux_state *state) +{ + void *policy = NULL; + char *policy_event_name = NULL; + size_t policy_len; + int rc = 0; + bool initialized = selinux_initialized(state); + + /* + * Measure SELinux policy only after initialization is completed. + */ + if (!initialized) + goto out; + + policy_event_name = selinux_event_name("selinux-policy-hash"); + if (!policy_event_name) { + pr_err("%s: Event name for policy not allocated.\n", + __func__); + rc = -ENOMEM; + goto out; + } + + rc = security_read_policy_kernel(state, &policy, &policy_len); + if (rc) { + pr_err("%s: Failed to read policy %d.\n", __func__, rc); + goto out; + } + + ima_measure_critical_data("selinux", policy_event_name, + policy, policy_len, true); + + vfree(policy); + +out: + kfree(policy_event_name); +} diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c index 9704c8a32303..dfa2e00894ae 100644 --- a/security/selinux/ss/services.c +++ b/security/selinux/ss/services.c @@ -2180,6 +2180,7 @@ static void selinux_notify_policy_change(struct selinux_state *state, selinux_status_update_policyload(state, seqno); selinux_netlbl_cache_invalidate(); selinux_xfrm_notify_policyload(); + selinux_measure_state(state); } void selinux_policy_commit(struct selinux_state *state, @@ -3875,8 +3876,33 @@ int security_netlbl_sid_to_secattr(struct selinux_state *state, } #endif /* CONFIG_NETLABEL */ +/** + * security_read_selinux_policy - read the policy. + * @policy: SELinux policy + * @data: binary policy data + * @len: length of data in bytes + * + */ +static int security_read_selinux_policy(struct selinux_policy *policy, + void *data, size_t *len) +{ + int rc; + struct policy_file fp; + + fp.data = data; + fp.len = *len; + + rc = policydb_write(&policy->policydb, &fp); + if (rc) + return rc; + + *len = (unsigned long)fp.data - (unsigned long)data; + return 0; +} + /** * security_read_policy - read the policy. + * @state: selinux_state * @data: binary policy data * @len: length of data in bytes * @@ -3885,8 +3911,6 @@ int security_read_policy(struct selinux_state *state, void **data, size_t *len) { struct selinux_policy *policy; - int rc; - struct policy_file fp; policy = rcu_dereference_protected( state->policy, lockdep_is_held(&state->policy_mutex)); @@ -3898,14 +3922,43 @@ int security_read_policy(struct selinux_state *state, if (!*data) return -ENOMEM; - fp.data = *data; - fp.len = *len; + return security_read_selinux_policy(policy, *data, len); +} - rc = policydb_write(&policy->policydb, &fp); - if (rc) - return rc; +/** + * security_read_policy_kernel - read the policy. + * @state: selinux_state + * @data: binary policy data + * @len: length of data in bytes + * + * Allocates kernel memory for reading SELinux policy. + * This function is for internal use only and should not + * be used for returning data to user space. + * + * This function must be called with policy_mutex held. + */ +int security_read_policy_kernel(struct selinux_state *state, + void **data, size_t *len) +{ + struct selinux_policy *policy; + int rc = 0; - *len = (unsigned long)fp.data - (unsigned long)*data; - return 0; + policy = rcu_dereference_protected( + state->policy, lockdep_is_held(&state->policy_mutex)); + if (!policy) { + rc = -EINVAL; + goto out; + } + + *len = policy->policydb.len; + *data = vmalloc(*len); + if (!*data) { + rc = -ENOMEM; + goto out; + } + rc = security_read_selinux_policy(policy, *data, len); + +out: + return rc; }