From patchwork Fri Jan 8 04:07:01 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tushar Sugandhi X-Patchwork-Id: 12005637 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=-26.3 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 B2A81C43603 for ; Fri, 8 Jan 2021 04:08:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8B06023601 for ; Fri, 8 Jan 2021 04:08:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727146AbhAHEIV (ORCPT ); Thu, 7 Jan 2021 23:08:21 -0500 Received: from linux.microsoft.com ([13.77.154.182]:59038 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727131AbhAHEIF (ORCPT ); Thu, 7 Jan 2021 23:08:05 -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 AC33020B6C40; Thu, 7 Jan 2021 20:07:22 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com AC33020B6C40 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1610078843; bh=dwDCjJq9eBFnM+xdiQHF37Or3L4akrthxuRwM8qTOLM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=d4Qt0MqLytXvucVMbq/JWCwEMvMcihpZaK5Xe48aLEri4SX+ag9q/kBD/YNZAQmLr grd5HR8IGnz8NZ53n/9M0I8zMwqFSy3xVIG245OcBDX7+Xoo3WAkuXHO+D/fi5t9Vb hIB3Gia6pCLatX0ghZ3VaifoZMU9FScbiNB6Gr9o= 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 v10 1/8] IMA: generalize keyring specific measurement constructs Date: Thu, 7 Jan 2021 20:07:01 -0800 Message-Id: <20210108040708.8389-2-tusharsu@linux.microsoft.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20210108040708.8389-1-tusharsu@linux.microsoft.com> References: <20210108040708.8389-1-tusharsu@linux.microsoft.com> Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org 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 | 43 +++++++++++++++++------------ 4 files changed, 35 insertions(+), 26 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..e76499b1ce78 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: func specific data, may 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..b4ed611cd2a4 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: func specific data, may 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..b93966034368 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -453,30 +453,40 @@ int ima_lsm_policy_change(struct notifier_block *nb, unsigned long event, } /** - * ima_match_keyring - determine whether the keyring matches the measure rule + * ima_match_rule_data - determine whether func_data matches the policy rule * @rule: a pointer to a rule - * @keyring: name of the keyring to match against the measure 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; + + opt_list = rule->keyrings; + break; + default: + return false; + } - if (!keyring) + if (!func_data) 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 +503,20 @@ 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: func specific data, may 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 +620,7 @@ 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: func specific data, may be NULL * * Measure decision based on func/mask/fsmagic and LSM(subj/obj/type) * conditions. @@ -623,7 +632,7 @@ 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 +647,7 @@ 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 Fri Jan 8 04:07:02 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tushar Sugandhi X-Patchwork-Id: 12005631 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=-26.3 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 6594DC43381 for ; Fri, 8 Jan 2021 04:08:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3BAE323770 for ; Fri, 8 Jan 2021 04:08:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727262AbhAHEIJ (ORCPT ); Thu, 7 Jan 2021 23:08:09 -0500 Received: from linux.microsoft.com ([13.77.154.182]:59056 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727146AbhAHEIF (ORCPT ); Thu, 7 Jan 2021 23:08:05 -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 405EF20B6C41; Thu, 7 Jan 2021 20:07:23 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 405EF20B6C41 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1610078843; bh=Sf3wZHyBGPrE4208f3+QIE6E6kkD2aNvO+IjtAAWPY8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CMcKRYsfjIZAV+k/NdbDUwN4cEKIZvR62XpQ7Wi4EHKRl41OZcftdOcA/n9sifTXU Ui4RXXgB31X8TAG628yv9DOvFVTyf4RxxazSVZkckJTW875CkhphN568UyYDw3o9KM 8NddBnKmPdm3XTGboBh1Xwc6ZaKOdWxjWkJtqk6A= 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 v10 2/8] IMA: add support to measure buffer data hash Date: Thu, 7 Jan 2021 20:07:02 -0800 Message-Id: <20210108040708.8389-3-tusharsu@linux.microsoft.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20210108040708.8389-1-tusharsu@linux.microsoft.com> References: <20210108040708.8389-1-tusharsu@linux.microsoft.com> Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org 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 buffer data hash. Introduce a boolean parameter to support measuring buffer data hash, which would be much smaller, instead of the buffer itself. Signed-off-by: Tushar Sugandhi Reviewed-by: Tyler Hicks --- 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 | 29 ++++++++++++++++---- security/integrity/ima/ima_queue_keys.c | 3 +- 5 files changed, 30 insertions(+), 9 deletions(-) diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index e5622ce8cbb1..0b4634515839 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 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 b4ed611cd2a4..494fb964497d 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 +787,14 @@ int ima_post_load_data(char *buf, loff_t size, * @func: IMA hook * @pcr: pcr to extend the measurement * @func_data: func specific data, may be NULL + * @buf_hash: measure buffer data hash * - * Based on policy, the buffer is measured into the ima log. + * Based on policy, either the buffer data or buffer data hash is measured */ 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 buf_hash) { int ret = 0; const char *audit_cause = "ENOMEM"; @@ -807,6 +809,8 @@ 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 digest_hash[IMA_MAX_DIGEST_SIZE]; + int digest_hash_len = hash_digest_size[ima_hash_algo]; int violation = 0; int action = 0; u32 secid; @@ -849,13 +853,27 @@ void process_buffer_measurement(struct inode *inode, const void *buf, int size, goto out; } + if (buf_hash) { + memcpy(digest_hash, hash.hdr.digest, digest_hash_len); + + ret = ima_calc_buffer_hash(digest_hash, digest_hash_len, + iint.ima_hash); + if (ret < 0) { + audit_cause = "hashing_error"; + goto out; + } + + event_data.buf = digest_hash; + event_data.buf_len = digest_hash_len; + } + ret = ima_alloc_init_template(&event_data, &entry, template); if (ret < 0) { audit_cause = "alloc_entry"; goto out; } - ret = ima_store_template(entry, violation, NULL, buf, pcr); + ret = ima_store_template(entry, violation, NULL, event_data.buf, pcr); if (ret < 0) { audit_cause = "store_entry"; ima_free_template_entry(entry); @@ -890,7 +908,8 @@ 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 Fri Jan 8 04:07:03 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tushar Sugandhi X-Patchwork-Id: 12005633 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=-26.3 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 B2EA9C4332B for ; Fri, 8 Jan 2021 04:08:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 888E423718 for ; Fri, 8 Jan 2021 04:08:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727239AbhAHEIJ (ORCPT ); Thu, 7 Jan 2021 23:08:09 -0500 Received: from linux.microsoft.com ([13.77.154.182]:59072 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727147AbhAHEIF (ORCPT ); Thu, 7 Jan 2021 23:08:05 -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 CFB7F20B6C42; Thu, 7 Jan 2021 20:07:23 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com CFB7F20B6C42 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1610078844; bh=1//phB4oDC0if4r5cArNbDu6FzSfpsU1LtpB80AJZy8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MT5qUHW6JuMDQWHVh54Kmwa+8ugEsRgxcxNKVNMAQ4f891gk2xoe+AJ2/59nL6GdA Yph2vWe2F2KsJEpbQ/kI64h2C1C0tmiZXK9jz4+zql5mi8L+Jv7yOUguFJR+PnrNJ9 oyabG1JSPJL7Yofi8nNi3SlhrCY2Vi/Nwl5g2fw4= 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 v10 3/8] IMA: define a hook to measure kernel integrity critical data Date: Thu, 7 Jan 2021 20:07:03 -0800 Message-Id: <20210108040708.8389-4-tusharsu@linux.microsoft.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20210108040708.8389-1-tusharsu@linux.microsoft.com> References: <20210108040708.8389-1-tusharsu@linux.microsoft.com> Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org IMA provides capabilities to measure file and 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 the system. Currently, IMA does not provide a generic function for measuring kernel integrity critical data. Define ima_measure_critical_data, a new IMA hook, to measure kernel integrity critical data. Signed-off-by: Tushar Sugandhi Reviewed-by: Tyler Hicks --- include/linux/ima.h | 7 +++++++ security/integrity/ima/ima.h | 1 + security/integrity/ima/ima_api.c | 2 +- security/integrity/ima/ima_main.c | 24 ++++++++++++++++++++++++ 4 files changed, 33 insertions(+), 1 deletion(-) diff --git a/include/linux/ima.h b/include/linux/ima.h index ac3d82f962f2..37a0727c1c31 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, size_t buf_len, + bool hash); #ifdef CONFIG_IMA_APPRAISE_BOOTPARAM extern void ima_appraise_parse_cmdline(void); @@ -122,6 +125,10 @@ 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, size_t buf_len, + bool hash) {} #endif /* CONFIG_IMA */ #ifndef CONFIG_IMA_KEXEC diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index 0b4634515839..aa312472c7c5 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 e76499b1ce78..1dd70dc68ffd 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 494fb964497d..ef37307e79dd 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -913,6 +913,30 @@ 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 for the record in the IMA measurement list + * @buf: pointer to buffer data + * @buf_len: length of buffer data (in bytes) + * @hash: measure buffer data hash + * + * Measure data critical to the integrity of the kernel into the IMA log + * and extend the pcr. Examples of critical data could be various data + * structures, policies, and states stored in kernel memory that can + * impact the integrity of the system. + */ +void ima_measure_critical_data(const char *event_name, + const void *buf, size_t buf_len, + bool hash) +{ + if (!event_name || !buf || !buf_len) + return; + + process_buffer_measurement(NULL, buf, buf_len, event_name, + CRITICAL_DATA, 0, NULL, + hash); +} + static int __init init_ima(void) { int error; From patchwork Fri Jan 8 04:07:04 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tushar Sugandhi X-Patchwork-Id: 12005635 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=-26.3 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 556BEC43333 for ; Fri, 8 Jan 2021 04:08:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2613623601 for ; Fri, 8 Jan 2021 04:08:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727130AbhAHEIJ (ORCPT ); Thu, 7 Jan 2021 23:08:09 -0500 Received: from linux.microsoft.com ([13.77.154.182]:59092 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727171AbhAHEIF (ORCPT ); Thu, 7 Jan 2021 23:08:05 -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 6461120B6C43; Thu, 7 Jan 2021 20:07:24 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 6461120B6C43 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1610078844; bh=/dhE5VvasOsSBolU0/egUt6kTVzgMHV7Jt2yMxl/f30=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=oI7TNo/RGQREIxqyNYLNqHPcMLVo1arBb8qj5nwnlk/oC4iYNY48UIDxRvAvFBHGI SlC57iucrz7VC7MvzmtMDhtDMVQdvk6ol7NptP+4978Jk0lLuJISniHEGO5XglaTmD P7c0PTA3JvJTXQpejfUFLN2JY7t7rEVcBdF0YAwY= 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 v10 4/8] IMA: add policy rule to measure critical data Date: Thu, 7 Jan 2021 20:07:04 -0800 Message-Id: <20210108040708.8389-5-tusharsu@linux.microsoft.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20210108040708.8389-1-tusharsu@linux.microsoft.com> References: <20210108040708.8389-1-tusharsu@linux.microsoft.com> Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org 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 policy rule support for measuring integrity critical data. Signed-off-by: Tushar Sugandhi Reviewed-by: Tyler Hicks Reviewed-by: Mimi Zohar --- Documentation/ABI/testing/ima_policy | 2 +- security/integrity/ima/ima_policy.c | 29 ++++++++++++++++++++++++---- 2 files changed, 26 insertions(+), 5 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/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index b93966034368..96ba4273c4d0 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -478,6 +478,8 @@ static bool ima_match_rule_data(struct ima_rule_entry *rule, opt_list = rule->keyrings; break; + case CRITICAL_DATA: + return true; default: return false; } @@ -514,13 +516,19 @@ 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; @@ -1115,6 +1123,17 @@ 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_FUNC | IMA_UID | IMA_PCR)) + return false; + + if (ima_rule_contains_lsm_cond(entry)) + return false; + break; default: return false; @@ -1247,6 +1266,8 @@ 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 Fri Jan 8 04:07:05 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tushar Sugandhi X-Patchwork-Id: 12005645 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=-26.3 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 780C0C43217 for ; Fri, 8 Jan 2021 04:09:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3D24623715 for ; Fri, 8 Jan 2021 04:09:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727464AbhAHEIp (ORCPT ); Thu, 7 Jan 2021 23:08:45 -0500 Received: from linux.microsoft.com ([13.77.154.182]:59247 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726776AbhAHEIp (ORCPT ); Thu, 7 Jan 2021 23:08:45 -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 F12E520B6C44; Thu, 7 Jan 2021 20:07:24 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com F12E520B6C44 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1610078845; bh=oP4hs57Ovo2mWRRk2dcebbPVikngKbjBbImBel4Stjo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=G7HhFWE2Q+GhEzDKvm2pshLCUMA3I880DIfAERIKxtYBJsuvzcpDLQLpsaBFQRQg6 GkaRh5fpPUYpnChAX7H5817+kvHf9ll9hWpS3gJ222wlzuPNtMcmWnMbWn4KPB8nWw aIIEl6iNb3K6YhU1Drv8gkA5U0tmBuWS0MsolHN4= 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 v10 5/8] IMA: limit critical data measurement based on a label Date: Thu, 7 Jan 2021 20:07:05 -0800 Message-Id: <20210108040708.8389-6-tusharsu@linux.microsoft.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20210108040708.8389-1-tusharsu@linux.microsoft.com> References: <20210108040708.8389-1-tusharsu@linux.microsoft.com> Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org Integrity critical data may belong to a single subsystem or it may arise from cross subsystem interaction. Currently there is no mechanism to group or limit the data based on certain label. Limiting and grouping critical data based on a label would make it flexible and configurable to measure. Define "label:=", a new IMA policy condition, for the IMA func CRITICAL_DATA to allow grouping and limiting measurement of integrity critical data. Limit the measurement to the labels that are specified in the IMA policy - CRITICAL_DATA+"label:=". If "label:=" is not provided with the func CRITICAL_DATA, measure all the input integrity critical data. Signed-off-by: Tushar Sugandhi Reviewed-by: Tyler Hicks --- Documentation/ABI/testing/ima_policy | 2 ++ security/integrity/ima/ima_policy.c | 37 +++++++++++++++++++++++++--- 2 files changed, 36 insertions(+), 3 deletions(-) diff --git a/Documentation/ABI/testing/ima_policy b/Documentation/ABI/testing/ima_policy index 6ec7daa87cba..54fe1c15ed50 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 + label:= [data_label] + data_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 96ba4273c4d0..2c9db2d0b434 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_LABEL 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 *label; /* Measure data grouped under this label */ struct ima_template_desc *template; }; @@ -479,7 +481,11 @@ static bool ima_match_rule_data(struct ima_rule_entry *rule, opt_list = rule->keyrings; break; case CRITICAL_DATA: - return true; + if (!rule->label) + return true; + + opt_list = rule->label; + break; default: return false; } @@ -924,7 +930,7 @@ 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_label, Opt_err }; static const match_table_t policy_tokens = { @@ -961,6 +967,7 @@ static const match_table_t policy_tokens = { {Opt_pcr, "pcr=%s"}, {Opt_template, "template=%s"}, {Opt_keyrings, "keyrings=%s"}, + {Opt_label, "label=%s"}, {Opt_err, NULL} }; @@ -1128,7 +1135,8 @@ static bool ima_validate_rule(struct ima_rule_entry *entry) if (entry->action & ~(MEASURE | DONT_MEASURE)) return false; - if (entry->flags & ~(IMA_FUNC | IMA_UID | IMA_PCR)) + if (entry->flags & ~(IMA_FUNC | IMA_UID | IMA_PCR | + IMA_LABEL)) return false; if (ima_rule_contains_lsm_cond(entry)) @@ -1338,6 +1346,23 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry) entry->flags |= IMA_KEYRINGS; break; + case Opt_label: + ima_log_string(ab, "label", args[0].from); + + if (entry->label) { + result = -EINVAL; + break; + } + + entry->label = ima_alloc_rule_opt_list(args); + if (IS_ERR(entry->label)) { + result = PTR_ERR(entry->label); + entry->label = NULL; + break; + } + + entry->flags |= IMA_LABEL; + break; case Opt_fsuuid: ima_log_string(ab, "fsuuid", args[0].from); @@ -1718,6 +1743,12 @@ int ima_policy_show(struct seq_file *m, void *v) seq_puts(m, " "); } + if (entry->flags & IMA_LABEL) { + seq_puts(m, "label="); + ima_show_rule_opt_list(m, entry->label); + seq_puts(m, " "); + } + if (entry->flags & IMA_PCR) { snprintf(tbuf, sizeof(tbuf), "%d", entry->pcr); seq_printf(m, pt(Opt_pcr), tbuf); From patchwork Fri Jan 8 04:07:06 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tushar Sugandhi X-Patchwork-Id: 12005643 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=-26.3 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 1BC6FC432C3 for ; Fri, 8 Jan 2021 04:09:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E4AFF23716 for ; Fri, 8 Jan 2021 04:09:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727474AbhAHEIq (ORCPT ); Thu, 7 Jan 2021 23:08:46 -0500 Received: from linux.microsoft.com ([13.77.154.182]:59246 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727453AbhAHEIp (ORCPT ); Thu, 7 Jan 2021 23:08:45 -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 892ED20B6C45; Thu, 7 Jan 2021 20:07:25 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 892ED20B6C45 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1610078846; bh=VIKMJbFu3cOL+5bOVp1iBn5J7QnndlyqYVvuPWOMxHo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nozqnuyNEh353Q4nxQavHSSiQ7vXvceqoXSVyr1uAummB94jPOYtDT6U5SsYsyeaK L7hvDb5jVEPaaWRENLP21XYYk66eUAKBJUxwwEnNHQKTyR5hi+0easlQIBDT1QZs0P fa89vIZd83MUi/1rBkXMn1dGQ+Qg6ViohLZd1g8E= 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 v10 6/8] IMA: extend critical data hook to limit the measurement based on a label Date: Thu, 7 Jan 2021 20:07:06 -0800 Message-Id: <20210108040708.8389-7-tusharsu@linux.microsoft.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20210108040708.8389-1-tusharsu@linux.microsoft.com> References: <20210108040708.8389-1-tusharsu@linux.microsoft.com> Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org 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 | 7 +++++-- security/integrity/ima/ima_main.c | 8 +++++--- 2 files changed, 10 insertions(+), 5 deletions(-) diff --git a/include/linux/ima.h b/include/linux/ima.h index 37a0727c1c31..6d00542de135 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_label, + const char *event_name, const void *buf, size_t buf_len, bool hash); @@ -126,9 +127,11 @@ 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_label, + const char *event_name, const void *buf, size_t buf_len, bool hash) {} + #endif /* CONFIG_IMA */ #ifndef CONFIG_IMA_KEXEC diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index ef37307e79dd..edfb1367a11d 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -915,6 +915,7 @@ void ima_kexec_cmdline(int kernel_fd, const void *buf, int size) /** * ima_measure_critical_data - measure kernel integrity critical data + * @event_label: unique event label for grouping and limiting critical data * @event_name: event name for the record in the IMA measurement list * @buf: pointer to buffer data * @buf_len: length of buffer data (in bytes) @@ -925,15 +926,16 @@ void ima_kexec_cmdline(int kernel_fd, const void *buf, int size) * structures, policies, and states stored in kernel memory that can * impact the integrity of the system. */ -void ima_measure_critical_data(const char *event_name, +void ima_measure_critical_data(const char *event_label, + const char *event_name, const void *buf, size_t buf_len, bool hash) { - if (!event_name || !buf || !buf_len) + if (!event_name || !event_label || !buf || !buf_len) return; process_buffer_measurement(NULL, buf, buf_len, event_name, - CRITICAL_DATA, 0, NULL, + CRITICAL_DATA, 0, event_label, hash); } From patchwork Fri Jan 8 04:07:07 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tushar Sugandhi X-Patchwork-Id: 12005641 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=-23.5 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 A4C40C43332 for ; Fri, 8 Jan 2021 04:09:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 84D7923715 for ; Fri, 8 Jan 2021 04:09:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727612AbhAHEIz (ORCPT ); Thu, 7 Jan 2021 23:08:55 -0500 Received: from linux.microsoft.com ([13.77.154.182]:59260 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727454AbhAHEIq (ORCPT ); Thu, 7 Jan 2021 23:08:46 -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 273D920B6C46; Thu, 7 Jan 2021 20:07:26 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 273D920B6C46 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1610078846; bh=NblfeM4gSvMTuDUnr/Ywi4/vYvY7tsPtE6p51c4jjrY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KTB1yGAbNVHfWJR6Tw/kNYwCDj3hdE5krKuPj5C0Oa9QiOhpDKgjTAdxK3p4WgctB mSavfFsrZhphARf9DfRA4Uxl2dtO2recLkn8EkoSltEOvBuOgPMO+hb++vE7ebbGrc 0oZNB2q722hUNtT2HzykKzKtltHC0O+2hnJrD84g= 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 v10 7/8] IMA: define a builtin critical data measurement policy Date: Thu, 7 Jan 2021 20:07:07 -0800 Message-Id: <20210108040708.8389-8-tusharsu@linux.microsoft.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20210108040708.8389-1-tusharsu@linux.microsoft.com> References: <20210108040708.8389-1-tusharsu@linux.microsoft.com> Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org 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. Update the documentation on kernel parameters to document the new critical data builtin policy. Signed-off-by: Lakshmi Ramasubramanian Reviewed-by: Tyler Hicks Reviewed-by: Mimi Zohar --- 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 2c9db2d0b434..9b45d064a87d 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 @@ -871,6 +878,11 @@ 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 Fri Jan 8 04:07:08 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tushar Sugandhi X-Patchwork-Id: 12005639 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=-26.3 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 235B2C43381 for ; Fri, 8 Jan 2021 04:09:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 048C423716 for ; Fri, 8 Jan 2021 04:09:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726869AbhAHEIs (ORCPT ); Thu, 7 Jan 2021 23:08:48 -0500 Received: from linux.microsoft.com ([13.77.154.182]:59258 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727455AbhAHEIr (ORCPT ); Thu, 7 Jan 2021 23:08:47 -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 B16DC20B6C47; Thu, 7 Jan 2021 20:07:26 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com B16DC20B6C47 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1610078847; bh=AgvYAJJjP1R66s0Ox9IE0VuR3xlSiEzYCYXqnGjJ/8U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QLv36zaq28Y7t/lSyM5Y79XKQ7tjLhsjhqsaBeIaR8Ja0sjKtILfSYB0W/5tLMuNY nK4j9LuuX5W9KtmjqwhwHfYx2Sgu7/i6jwJLIwROs9p9juXr/YaXGs6t3KulJnso15 zqvmuqBEXlGZQJD/OUgkx/zyrh0y0patvMKFnn2M= 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 v10 8/8] selinux: include a consumer of the new IMA critical data hook Date: Thu, 7 Jan 2021 20:07:08 -0800 Message-Id: <20210108040708.8389-9-tusharsu@linux.microsoft.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20210108040708.8389-1-tusharsu@linux.microsoft.com> References: <20210108040708.8389-1-tusharsu@linux.microsoft.com> Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org From: Lakshmi Ramasubramanian SELinux stores the active policy in memory, so the changes to this data at runtime would have an impact on the security guarantees provided by SELinux. Measuring in-memory SELinux policy through IMA subsystem provides a secure way for the attestation service to remotely validate the policy contents at runtime. 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. 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 label=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 Reviewed-by: Tyler Hicks Acked-by: Paul Moore --- Documentation/ABI/testing/ima_policy | 3 +- security/selinux/Makefile | 2 + security/selinux/ima.c | 64 ++++++++++++++++++++++++++++ security/selinux/include/ima.h | 24 +++++++++++ security/selinux/include/security.h | 3 +- security/selinux/ss/services.c | 64 ++++++++++++++++++++++++---- 6 files changed, 149 insertions(+), 11 deletions(-) create mode 100644 security/selinux/ima.c create mode 100644 security/selinux/include/ima.h diff --git a/Documentation/ABI/testing/ima_policy b/Documentation/ABI/testing/ima_policy index 54fe1c15ed50..8365596cb42b 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 - label:= [data_label] + label:= [selinux]|[data_label] data_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..776162444882 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-$(CONFIG_IMA) += ima.o + ccflags-y := -I$(srctree)/security/selinux -I$(srctree)/security/selinux/include $(addprefix $(obj)/,$(selinux-y)): $(obj)/flask.h diff --git a/security/selinux/ima.c b/security/selinux/ima.c new file mode 100644 index 000000000000..0b835bdc3aa9 --- /dev/null +++ b/security/selinux/ima.c @@ -0,0 +1,64 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (C) 2021 Microsoft Corporation + * + * Author: Lakshmi Ramasubramanian (nramas@linux.microsoft.com) + * + * Measure critical data structures maintainted by SELinux + * using IMA subsystem. + */ +#include +#include +#include +#include "security.h" +#include "ima.h" + +/* + * selinux_ima_measure_state - Measure hash of the SELinux policy + * + * @state: selinux state struct + * + * NOTE: This function must be called with policy_mutex held. + */ +void selinux_ima_measure_state(struct selinux_state *state) +{ + struct timespec64 cur_time; + void *policy = NULL; + char *policy_event_name = NULL; + size_t policy_len; + int rc = 0; + + /* + * Measure SELinux policy only after initialization is completed. + */ + if (!selinux_initialized(state)) + return; + + /* + * Pass a unique "event_name" to the IMA hook so that IMA subsystem + * will always measure the given data. + */ + ktime_get_real_ts64(&cur_time); + policy_event_name = kasprintf(GFP_KERNEL, "%s-%lld:%09ld", + "selinux-policy-hash", + cur_time.tv_sec, cur_time.tv_nsec); + if (!policy_event_name) { + pr_err("SELinux: %s: event name for policy not allocated.\n", + __func__); + goto out; + } + + rc = security_read_state_kernel(state, &policy, &policy_len); + if (rc) { + pr_err("SELinux: %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/include/ima.h b/security/selinux/include/ima.h new file mode 100644 index 000000000000..d69c36611423 --- /dev/null +++ b/security/selinux/include/ima.h @@ -0,0 +1,24 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * Copyright (C) 2021 Microsoft Corporation + * + * Author: Lakshmi Ramasubramanian (nramas@linux.microsoft.com) + * + * Measure critical data structures maintainted by SELinux + * using IMA subsystem. + */ + +#ifndef _SELINUX_IMA_H_ +#define _SELINUX_IMA_H_ + +#include "security.h" + +#ifdef CONFIG_IMA +extern void selinux_ima_measure_state(struct selinux_state *selinux_state); +#else +static inline void selinux_ima_measure_state(struct selinux_state *selinux_state) +{ +} +#endif + +#endif /* _SELINUX_IMA_H_ */ diff --git a/security/selinux/include/security.h b/security/selinux/include/security.h index 3cc8bab31ea8..29cae32d3fc5 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_state_kernel(struct selinux_state *state, + void **data, size_t *len); int security_policycap_supported(struct selinux_state *state, unsigned int req_cap); diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c index 9704c8a32303..cc8dbc4ed8db 100644 --- a/security/selinux/ss/services.c +++ b/security/selinux/ss/services.c @@ -65,6 +65,7 @@ #include "ebitmap.h" #include "audit.h" #include "policycap_names.h" +#include "ima.h" /* Forward declaration. */ static int context_struct_to_string(struct policydb *policydb, @@ -2180,6 +2181,7 @@ 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_ima_measure_state(state); } void selinux_policy_commit(struct selinux_state *state, @@ -3875,8 +3877,33 @@ int security_netlbl_sid_to_secattr(struct selinux_state *state, } #endif /* CONFIG_NETLABEL */ +/** + * __security_read_policy - read the policy. + * @policy: SELinux policy + * @data: binary policy data + * @len: length of data in bytes + * + */ +static int __security_read_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 +3912,6 @@ 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 +3923,35 @@ int security_read_policy(struct selinux_state *state, if (!*data) return -ENOMEM; - fp.data = *data; - fp.len = *len; + return __security_read_policy(policy, *data, len); +} - rc = policydb_write(&policy->policydb, &fp); - if (rc) - return rc; +/** + * security_read_state_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_state_kernel(struct selinux_state *state, + void **data, size_t *len) +{ + struct selinux_policy *policy; - *len = (unsigned long)fp.data - (unsigned long)*data; - return 0; + policy = rcu_dereference_protected( + state->policy, lockdep_is_held(&state->policy_mutex)); + if (!policy) + return -EINVAL; + + *len = policy->policydb.len; + *data = vmalloc(*len); + if (!*data) + return -ENOMEM; + return __security_read_policy(policy, *data, len); }