From patchwork Wed Jun 30 14:16:34 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roberto Sassu X-Patchwork-Id: 12352251 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 17DC2C11F68 for ; Wed, 30 Jun 2021 14:16:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 026986144C for ; Wed, 30 Jun 2021 14:16:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234851AbhF3OTY (ORCPT ); Wed, 30 Jun 2021 10:19:24 -0400 Received: from frasgout.his.huawei.com ([185.176.79.56]:3334 "EHLO frasgout.his.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234996AbhF3OTW (ORCPT ); Wed, 30 Jun 2021 10:19:22 -0400 Received: from fraeml714-chm.china.huawei.com (unknown [172.18.147.201]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4GFNW52ZFXz6H6ml; Wed, 30 Jun 2021 22:09:05 +0800 (CST) Received: from roberto-ThinkStation-P620.huawei.com (10.204.63.22) by fraeml714-chm.china.huawei.com (10.206.15.33) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Wed, 30 Jun 2021 16:16:50 +0200 From: Roberto Sassu To: , CC: , , , , , , , , Roberto Sassu Subject: [PATCH 2/3] ima: Return int in the functions to measure a buffer Date: Wed, 30 Jun 2021 16:16:34 +0200 Message-ID: <20210630141635.2862222-3-roberto.sassu@huawei.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210630141635.2862222-1-roberto.sassu@huawei.com> References: <20210630141635.2862222-1-roberto.sassu@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.204.63.22] X-ClientProxiedBy: lhreml754-chm.china.huawei.com (10.201.108.204) To fraeml714-chm.china.huawei.com (10.206.15.33) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: selinux@vger.kernel.org ima_measure_critical_data() and process_buffer_measurement() currently don't return a result. A caller wouldn't be able to know whether those functions were executed successfully. This patch modifies the return type from void to int, and returns 0 if the buffer has been successfully measured, a negative value otherwise. Also, this patch does not modify the behavior of existing callers by processing the returned value. Instead, the value is stored in a variable marked as __maybe_unused. Signed-off-by: Roberto Sassu --- include/linux/ima.h | 15 ++++--- security/integrity/ima/ima.h | 10 ++--- security/integrity/ima/ima_appraise.c | 4 +- security/integrity/ima/ima_asymmetric_keys.c | 4 +- security/integrity/ima/ima_init.c | 6 ++- security/integrity/ima/ima_main.c | 46 ++++++++++++-------- security/integrity/ima/ima_queue_keys.c | 15 ++++--- security/selinux/ima.c | 10 +++-- 8 files changed, 65 insertions(+), 45 deletions(-) diff --git a/include/linux/ima.h b/include/linux/ima.h index 81e830d01ced..60492263aa64 100644 --- a/include/linux/ima.h +++ b/include/linux/ima.h @@ -35,10 +35,10 @@ extern void ima_post_path_mknod(struct user_namespace *mnt_userns, extern int ima_file_hash(struct file *file, char *buf, size_t buf_size); extern int ima_inode_hash(struct inode *inode, 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_label, - const char *event_name, - const void *buf, size_t buf_len, - bool hash); +extern int ima_measure_critical_data(const char *event_label, + 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); @@ -144,10 +144,13 @@ static inline int ima_inode_hash(struct inode *inode, 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_label, +static inline int ima_measure_critical_data(const char *event_label, const char *event_name, const void *buf, size_t buf_len, - bool hash) {} + bool hash) +{ + return -ENOENT; +} #endif /* CONFIG_IMA */ diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index f0e448ed1f9f..03db221324c3 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -264,11 +264,11 @@ void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file, struct evm_ima_xattr_data *xattr_value, int xattr_len, const struct modsig *modsig, int pcr, struct ima_template_desc *template_desc); -void process_buffer_measurement(struct user_namespace *mnt_userns, - struct inode *inode, const void *buf, int size, - const char *eventname, enum ima_hooks func, - int pcr, const char *func_data, - bool buf_hash); +int process_buffer_measurement(struct user_namespace *mnt_userns, + struct inode *inode, const void *buf, int size, + const char *eventname, enum ima_hooks func, + 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 ef9dcfce45d4..275a2377743f 100644 --- a/security/integrity/ima/ima_appraise.c +++ b/security/integrity/ima/ima_appraise.c @@ -345,6 +345,7 @@ int ima_check_blacklist(struct integrity_iint_cache *iint, enum hash_algo hash_algo; const u8 *digest = NULL; u32 digestsize = 0; + int process_rc __maybe_unused; int rc = 0; if (!(iint->flags & IMA_CHECK_BLACKLIST)) @@ -355,7 +356,8 @@ int ima_check_blacklist(struct integrity_iint_cache *iint, rc = is_binary_blacklisted(digest, digestsize); if ((rc == -EPERM) && (iint->flags & IMA_MEASURE)) - process_buffer_measurement(&init_user_ns, NULL, digest, digestsize, + process_rc = process_buffer_measurement(&init_user_ns, + NULL, digest, digestsize, "blacklisted-hash", NONE, pcr, NULL, false); } diff --git a/security/integrity/ima/ima_asymmetric_keys.c b/security/integrity/ima/ima_asymmetric_keys.c index c985418698a4..910367cdd920 100644 --- a/security/integrity/ima/ima_asymmetric_keys.c +++ b/security/integrity/ima/ima_asymmetric_keys.c @@ -31,6 +31,7 @@ void ima_post_key_create_or_update(struct key *keyring, struct key *key, unsigned long flags, bool create) { bool queued = false; + int ret __maybe_unused; /* Only asymmetric keys are handled by this hook. */ if (key->type != &key_type_asymmetric) @@ -60,7 +61,8 @@ void ima_post_key_create_or_update(struct key *keyring, struct key *key, * if the IMA policy is configured to measure a key linked * to the given keyring. */ - process_buffer_measurement(&init_user_ns, NULL, payload, payload_len, + ret = process_buffer_measurement(&init_user_ns, NULL, + payload, payload_len, keyring->description, KEY_CHECK, 0, keyring->description, false); } diff --git a/security/integrity/ima/ima_init.c b/security/integrity/ima/ima_init.c index 5076a7d9d23e..6790eea88db8 100644 --- a/security/integrity/ima/ima_init.c +++ b/security/integrity/ima/ima_init.c @@ -118,6 +118,7 @@ void __init ima_load_x509(void) int __init ima_init(void) { + int measure_rc __maybe_unused; int rc; ima_tpm_chip = tpm_default_chip(); @@ -153,8 +154,9 @@ int __init ima_init(void) ima_init_key_queue(); - ima_measure_critical_data("kernel_info", "kernel_version", - UTS_RELEASE, strlen(UTS_RELEASE), false); + measure_rc = ima_measure_critical_data("kernel_info", "kernel_version", + UTS_RELEASE, strlen(UTS_RELEASE), + false); return rc; } diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index 8ef1fa357e0c..45e048899b2f 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -840,12 +840,15 @@ int ima_post_load_data(char *buf, loff_t size, * @buf_hash: measure buffer data hash * * Based on policy, either the buffer data or buffer data hash is measured + * + * Returns 0 if the buffer has been successfully measured, a negative value + * otherwise. */ -void process_buffer_measurement(struct user_namespace *mnt_userns, - struct inode *inode, const void *buf, int size, - const char *eventname, enum ima_hooks func, - int pcr, const char *func_data, - bool buf_hash) +int process_buffer_measurement(struct user_namespace *mnt_userns, + struct inode *inode, const void *buf, int size, + const char *eventname, enum ima_hooks func, + int pcr, const char *func_data, + bool buf_hash) { int ret = 0; const char *audit_cause = "ENOMEM"; @@ -867,7 +870,7 @@ void process_buffer_measurement(struct user_namespace *mnt_userns, u32 secid; if (!ima_policy_flag) - return; + return -ENOENT; template = ima_template_desc_buf(); if (!template) { @@ -889,7 +892,7 @@ void process_buffer_measurement(struct user_namespace *mnt_userns, secid, 0, func, &pcr, &template, func_data); if (!(action & IMA_MEASURE)) - return; + return -ENOENT; } if (!pcr) @@ -937,7 +940,7 @@ void process_buffer_measurement(struct user_namespace *mnt_userns, func_measure_str(func), audit_cause, ret, 0, ret); - return; + return ret; } /** @@ -951,6 +954,7 @@ void process_buffer_measurement(struct user_namespace *mnt_userns, void ima_kexec_cmdline(int kernel_fd, const void *buf, int size) { struct fd f; + int ret __maybe_unused; if (!buf || !size) return; @@ -959,9 +963,10 @@ void ima_kexec_cmdline(int kernel_fd, const void *buf, int size) if (!f.file) return; - process_buffer_measurement(file_mnt_user_ns(f.file), file_inode(f.file), - buf, size, "kexec-cmdline", KEXEC_CMDLINE, 0, - NULL, false); + ret = process_buffer_measurement(file_mnt_user_ns(f.file), + file_inode(f.file), buf, size, + "kexec-cmdline", KEXEC_CMDLINE, 0, + NULL, false); fdput(f); } @@ -977,18 +982,21 @@ void ima_kexec_cmdline(int kernel_fd, const void *buf, int size) * 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. + * + * Returns 0 if the buffer has been successfully measured, a negative value + * otherwise. */ -void ima_measure_critical_data(const char *event_label, - const char *event_name, - const void *buf, size_t buf_len, - bool hash) +int ima_measure_critical_data(const char *event_label, + const char *event_name, + const void *buf, size_t buf_len, + bool hash) { if (!event_name || !event_label || !buf || !buf_len) - return; + return -ENOPARAM; - process_buffer_measurement(&init_user_ns, NULL, buf, buf_len, event_name, - CRITICAL_DATA, 0, event_label, - hash); + return process_buffer_measurement(&init_user_ns, NULL, buf, buf_len, + event_name, CRITICAL_DATA, 0, + event_label, hash); } static int __init init_ima(void) diff --git a/security/integrity/ima/ima_queue_keys.c b/security/integrity/ima/ima_queue_keys.c index 979ef6c71f3d..e3047ce64f39 100644 --- a/security/integrity/ima/ima_queue_keys.c +++ b/security/integrity/ima/ima_queue_keys.c @@ -134,6 +134,7 @@ void ima_process_queued_keys(void) { struct ima_key_entry *entry, *tmp; bool process = false; + int ret __maybe_unused; if (ima_process_keys) return; @@ -159,13 +160,13 @@ void ima_process_queued_keys(void) list_for_each_entry_safe(entry, tmp, &ima_keys, list) { if (!timer_expired) - process_buffer_measurement(&init_user_ns, NULL, - entry->payload, - entry->payload_len, - entry->keyring_name, - KEY_CHECK, 0, - entry->keyring_name, - false); + ret = process_buffer_measurement(&init_user_ns, NULL, + entry->payload, + entry->payload_len, + entry->keyring_name, + KEY_CHECK, 0, + entry->keyring_name, + false); list_del(&entry->list); ima_free_key_entry(entry); } diff --git a/security/selinux/ima.c b/security/selinux/ima.c index 34d421861bfc..4db9fa211638 100644 --- a/security/selinux/ima.c +++ b/security/selinux/ima.c @@ -75,6 +75,7 @@ void selinux_ima_measure_state_locked(struct selinux_state *state) char *state_str = NULL; void *policy = NULL; size_t policy_len; + int measure_rc __maybe_unused; int rc = 0; WARN_ON(!mutex_is_locked(&state->policy_mutex)); @@ -85,8 +86,9 @@ void selinux_ima_measure_state_locked(struct selinux_state *state) return; } - ima_measure_critical_data("selinux", "selinux-state", - state_str, strlen(state_str), false); + measure_rc = ima_measure_critical_data("selinux", "selinux-state", + state_str, strlen(state_str), + false); kfree(state_str); @@ -102,8 +104,8 @@ void selinux_ima_measure_state_locked(struct selinux_state *state) return; } - ima_measure_critical_data("selinux", "selinux-policy-hash", - policy, policy_len, true); + measure_rc = ima_measure_critical_data("selinux", "selinux-policy-hash", + policy, policy_len, true); vfree(policy); }