From patchwork Wed Aug 12 19:31:00 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tushar Sugandhi X-Patchwork-Id: 11711253 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 4E9C4722 for ; Wed, 12 Aug 2020 19:31:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 36DA92087C for ; Wed, 12 Aug 2020 19:31:26 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="K7Q8VNbu" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726713AbgHLTbP (ORCPT ); Wed, 12 Aug 2020 15:31:15 -0400 Received: from linux.microsoft.com ([13.77.154.182]:51148 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726542AbgHLTbO (ORCPT ); Wed, 12 Aug 2020 15:31:14 -0400 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 A784720B490A; Wed, 12 Aug 2020 12:31:11 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com A784720B490A DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1597260672; bh=WM9TCg90Hx4MS02p/HtWcv3wL5+9NlYpMBox6b3iuJc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=K7Q8VNbuAGyAxFZ9fqRCpvzxgbpEeu9HHbXlSFgxinl+ReKQEQiRHhInJDVREr3wb eNZ3gntf+aaeZhVLl+a8vbAvOtU+fMGAOKj1FF0i2WLJkhqUZPA5Z/fyJ5McjwGVf/ YyQpC4Wxlp86oeXp6VJV7/gRVgYfYsfpojM1iMTA= From: Tushar Sugandhi To: zohar@linux.ibm.com, stephen.smalley.work@gmail.com, casey@schaufler-ca.com, gmazyland@gmail.com Cc: tyhicks@linux.microsoft.com, sashal@kernel.org, jmorris@namei.org, linux-integrity@vger.kernel.org, selinux@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, dm-devel@redhat.com, nramas@linux.microsoft.com Subject: [PATCH 1/3] IMA: generalize keyring specific measurement constructs Date: Wed, 12 Aug 2020 12:31:00 -0700 Message-Id: <20200812193102.18636-2-tusharsu@linux.microsoft.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200812193102.18636-1-tusharsu@linux.microsoft.com> References: <20200812193102.18636-1-tusharsu@linux.microsoft.com> Sender: linux-integrity-owner@vger.kernel.org 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 without code duplication. Refactor the keyring specific measurement constructs to be generic and reusable in other measurement scenarios. Rename the parameter "size" in process_buffer_measurement() to "buf_len" to indicate it is the length of the buffer pointed by the parameter "buf". Signed-off-by: Tushar Sugandhi --- security/integrity/ima/ima.h | 11 ++++---- security/integrity/ima/ima_api.c | 6 ++--- security/integrity/ima/ima_main.c | 17 ++++++------ security/integrity/ima/ima_policy.c | 40 +++++++++++++++++------------ 4 files changed, 41 insertions(+), 33 deletions(-) diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index 38043074ce5e..e2a151d6653d 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -255,7 +255,7 @@ 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, @@ -265,9 +265,10 @@ void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file, struct evm_ima_xattr_data *xattr_value, int xattr_len, const struct modsig *modsig, int pcr, struct ima_template_desc *template_desc); -void process_buffer_measurement(struct inode *inode, const void *buf, int size, - const char *eventname, enum ima_hooks func, - int pcr, const char *keyring); +void process_buffer_measurement(struct inode *inode, const void *buf, + int buf_len, const char *eventname, + enum ima_hooks func, 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, @@ -283,7 +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 8a91711ca79b..a8740b7ea417 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -728,17 +728,18 @@ int ima_load_data(enum kernel_load_data_id id) * process_buffer_measurement - Measure the buffer to ima log. * @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). + * @buf_len: length of buffer(in bytes). * @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) +void process_buffer_measurement(struct inode *inode, const void *buf, + int buf_len, const char *eventname, + enum ima_hooks func, int pcr, + const char *func_data) { int ret = 0; const char *audit_cause = "ENOMEM"; @@ -747,7 +748,7 @@ void process_buffer_measurement(struct inode *inode, const void *buf, int size, struct ima_event_data event_data = {.iint = &iint, .filename = eventname, .buf = buf, - .buf_len = size}; + .buf_len = buf_len}; struct ima_template_desc *template = NULL; struct { struct ima_digest_data hdr; @@ -770,7 +771,7 @@ 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; } @@ -795,7 +796,7 @@ void process_buffer_measurement(struct inode *inode, const void *buf, int size, iint.ima_hash->algo = ima_hash_algo; iint.ima_hash->length = hash_digest_size[ima_hash_algo]; - ret = ima_calc_buffer_hash(buf, size, iint.ima_hash); + ret = ima_calc_buffer_hash(buf, buf_len, iint.ima_hash); if (ret < 0) { audit_cause = "hashing_error"; goto out; diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index fe1df373c113..4efaf8956eb8 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -451,15 +451,21 @@ 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 + * @opt_list: rule data to match func_data against + * @func_data: data to match against the measure rule data + * @allow_empty_opt_list: If true matches all func_data * @cred: a pointer to a credentials structure for user validation * * Returns true if keyring 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 struct ima_rule_opt_list *opt_list, + const char *func_data, + bool allow_empty_opt_list, + const struct cred *cred) { bool matched = false; size_t i; @@ -467,14 +473,14 @@ static bool ima_match_keyring(struct ima_rule_entry *rule, if ((rule->flags & IMA_UID) && !rule->uid_op(cred->uid, rule->uid)) return false; - if (!rule->keyrings) - return true; + if (!opt_list) + return allow_empty_opt_list; - 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; } @@ -491,20 +497,21 @@ 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, rule->keyrings, func_data, + true, cred); } if ((rule->flags & IMA_FUNC) && (rule->func != func && func != POST_SETATTR)) @@ -608,8 +615,7 @@ 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. @@ -621,7 +627,7 @@ 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); @@ -636,7 +642,7 @@ 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 Aug 12 19:31:01 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tushar Sugandhi X-Patchwork-Id: 11711261 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 802BC1744 for ; Wed, 12 Aug 2020 19:31:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 66F4520774 for ; Wed, 12 Aug 2020 19:31:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="MIxMEJeI" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726651AbgHLTb1 (ORCPT ); Wed, 12 Aug 2020 15:31:27 -0400 Received: from linux.microsoft.com ([13.77.154.182]:51170 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726681AbgHLTbO (ORCPT ); Wed, 12 Aug 2020 15:31:14 -0400 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 3C4B120B490D; Wed, 12 Aug 2020 12:31:12 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 3C4B120B490D DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1597260672; bh=1JH4jChNS0fa5DFFMyXyCP3gvcSLfR3XN5s6YUWp8Eg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MIxMEJeISvTQ7NN5IisP4jWYFX4zFj3WHpvnd+9p1LDZgpMXGC+bckHZqRClUr+Nc PkHUFZMNpr92w7Aw0Xl258nJ9C9Be+thQmt+eyIUo9K5LrICU+WDKg59D7I6nKZvdI vY8c9rsHafodvjTnRv3J4EINhRMUu2+9wRaRHmpY= From: Tushar Sugandhi To: zohar@linux.ibm.com, stephen.smalley.work@gmail.com, casey@schaufler-ca.com, gmazyland@gmail.com Cc: tyhicks@linux.microsoft.com, sashal@kernel.org, jmorris@namei.org, linux-integrity@vger.kernel.org, selinux@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, dm-devel@redhat.com, nramas@linux.microsoft.com Subject: [PATCH 2/3] IMA: add policy to support measuring critical data from kernel components Date: Wed, 12 Aug 2020 12:31:01 -0700 Message-Id: <20200812193102.18636-3-tusharsu@linux.microsoft.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200812193102.18636-1-tusharsu@linux.microsoft.com> References: <20200812193102.18636-1-tusharsu@linux.microsoft.com> Sender: linux-integrity-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org There would be several candidate kernel components suitable for IMA measurement. Not all of them would be enlightened for IMA measurement. Also, system administrators may not want to measure data for all of them, even when they are enlightened for IMA measurements. An IMA policy specific to various kernel components is needed to measure their respective critical data. Add a new IMA policy CRITICAL_DATA+data_sources to support measuring various critical kernel components. This policy would enable the system administrators to limit the measurement to the components, if the components are enlightened for IMA measurement. Signed-off-by: Tushar Sugandhi --- Documentation/ABI/testing/ima_policy | 6 +- security/integrity/ima/ima.h | 1 + security/integrity/ima/ima_api.c | 2 +- security/integrity/ima/ima_policy.c | 84 ++++++++++++++++++++++------ 4 files changed, 74 insertions(+), 19 deletions(-) diff --git a/Documentation/ABI/testing/ima_policy b/Documentation/ABI/testing/ima_policy index cd572912c593..a0dd0f108555 100644 --- a/Documentation/ABI/testing/ima_policy +++ b/Documentation/ABI/testing/ima_policy @@ -29,7 +29,7 @@ Description: base: 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 @@ -125,3 +125,7 @@ Description: keys added to .builtin_trusted_keys or .ima keyring: measure func=KEY_CHECK keyrings=.builtin_trusted_keys|.ima + + Example of measure rule using CRITICAL_DATA to measure critical data + + measure func=CRITICAL_DATA data_sources=selinux|apparmor|dm-crypt diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index e2a151d6653d..99773dfa2541 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -200,6 +200,7 @@ 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_policy.c b/security/integrity/ima/ima_policy.c index 4efaf8956eb8..8451ccb2a775 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -22,17 +22,18 @@ #include "ima.h" /* flags definitions */ -#define IMA_FUNC 0x0001 -#define IMA_MASK 0x0002 -#define IMA_FSMAGIC 0x0004 -#define IMA_UID 0x0008 -#define IMA_FOWNER 0x0010 -#define IMA_FSUUID 0x0020 -#define IMA_INMASK 0x0040 -#define IMA_EUID 0x0080 -#define IMA_PCR 0x0100 -#define IMA_FSNAME 0x0200 -#define IMA_KEYRINGS 0x0400 +#define IMA_FUNC 0x0001 +#define IMA_MASK 0x0002 +#define IMA_FSMAGIC 0x0004 +#define IMA_UID 0x0008 +#define IMA_FOWNER 0x0010 +#define IMA_FSUUID 0x0020 +#define IMA_INMASK 0x0040 +#define IMA_EUID 0x0080 +#define IMA_PCR 0x0100 +#define IMA_FSNAME 0x0200 +#define IMA_KEYRINGS 0x0400 +#define IMA_DATA_SOURCES 0x0800 #define UNKNOWN 0 #define MEASURE 0x0001 /* same as IMA_MEASURE */ @@ -84,6 +85,7 @@ 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_sources; /* Measure data from these sources */ struct ima_template_desc *template; }; @@ -508,14 +510,23 @@ 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, rule->keyrings, func_data, - true, cred); - } if ((rule->flags & IMA_FUNC) && (rule->func != func && func != POST_SETATTR)) return false; + + switch (func) { + case KEY_CHECK: + return ((rule->func == func) && + ima_match_rule_data(rule, rule->keyrings, + func_data, true, cred)); + case CRITICAL_DATA: + return ((rule->func == func) && + ima_match_rule_data(rule, rule->data_sources, + func_data, false, cred)); + default: + break; + } + if ((rule->flags & IMA_MASK) && (rule->mask != mask && func != POST_SETATTR)) return false; @@ -911,7 +922,7 @@ 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_sources, Opt_err }; static const match_table_t policy_tokens = { @@ -948,6 +959,7 @@ static const match_table_t policy_tokens = { {Opt_pcr, "pcr=%s"}, {Opt_template, "template=%s"}, {Opt_keyrings, "keyrings=%s"}, + {Opt_data_sources, "data_sources=%s"}, {Opt_err, NULL} }; @@ -1110,6 +1122,19 @@ 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_SOURCES) || + (entry->flags & ~(IMA_FUNC | IMA_UID | IMA_PCR | + IMA_DATA_SOURCES))) + return false; + + if (ima_rule_contains_lsm_cond(entry)) + return false; + break; default: return false; @@ -1242,6 +1267,8 @@ 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) @@ -1312,6 +1339,23 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry) entry->flags |= IMA_KEYRINGS; break; + case Opt_data_sources: + ima_log_string(ab, "data_sources", args[0].from); + + if (entry->data_sources) { + result = -EINVAL; + break; + } + + entry->data_sources = ima_alloc_rule_opt_list(args); + if (IS_ERR(entry->data_sources)) { + result = PTR_ERR(entry->data_sources); + entry->data_sources = NULL; + break; + } + + entry->flags |= IMA_DATA_SOURCES; + break; case Opt_fsuuid: ima_log_string(ab, "fsuuid", args[0].from); @@ -1692,6 +1736,12 @@ int ima_policy_show(struct seq_file *m, void *v) seq_puts(m, " "); } + if (entry->flags & IMA_DATA_SOURCES) { + seq_puts(m, "data_sources="); + ima_show_rule_opt_list(m, entry->data_sources); + 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 Aug 12 19:31:02 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tushar Sugandhi X-Patchwork-Id: 11711249 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 11EBD138C for ; Wed, 12 Aug 2020 19:31:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E2C5620774 for ; Wed, 12 Aug 2020 19:31:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="DrpNiLGu" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726752AbgHLTbP (ORCPT ); Wed, 12 Aug 2020 15:31:15 -0400 Received: from linux.microsoft.com ([13.77.154.182]:51194 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726685AbgHLTbN (ORCPT ); Wed, 12 Aug 2020 15:31:13 -0400 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 AFB8F20B490F; Wed, 12 Aug 2020 12:31:12 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com AFB8F20B490F DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1597260673; bh=dl4AP1i8JV+YnqMmI4cnuYcfwZNhDk56gzoeOIvJWD4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DrpNiLGuE7CfnVRD0Etx2OffpwQ6uf7ETRYGWnRz9wmyl+EKPrMpQvdpJPz3+5xvk cdiuFpj/5KprQQGoCD0uWHKDlYBGFtjLuM5wN//i07/Lkxz7EndIorYaveZ3tuAV5X sZsaQHtFC62E+fQyxHj6/jUG0bEOIID/5sSFCC9Q= From: Tushar Sugandhi To: zohar@linux.ibm.com, stephen.smalley.work@gmail.com, casey@schaufler-ca.com, gmazyland@gmail.com Cc: tyhicks@linux.microsoft.com, sashal@kernel.org, jmorris@namei.org, linux-integrity@vger.kernel.org, selinux@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, dm-devel@redhat.com, nramas@linux.microsoft.com Subject: [PATCH 3/3] IMA: define IMA hook to measure critical data from kernel components Date: Wed, 12 Aug 2020 12:31:02 -0700 Message-Id: <20200812193102.18636-4-tusharsu@linux.microsoft.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200812193102.18636-1-tusharsu@linux.microsoft.com> References: <20200812193102.18636-1-tusharsu@linux.microsoft.com> Sender: linux-integrity-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org Currently, IMA does not provide a generic function to kernel components to measure their data. A generic function provided by IMA would enable various parts of the kernel with easier and faster on-boarding to use IMA infrastructure, would avoid code duplication, and consistent usage of IMA policy CRITICAL_DATA+data_sources across the kernel. Define a generic IMA function ima_measure_critical_data() to measure data from various kernel components. Limit the measurement to the components that are specified in the IMA policy - CRITICAL_DATA+data_sources. Update process_buffer_measurement() to return the status code of the operation. Signed-off-by: Tushar Sugandhi --- include/linux/ima.h | 9 ++++++++ security/integrity/ima/ima.h | 8 +++---- security/integrity/ima/ima_main.c | 37 ++++++++++++++++++++++++------- 3 files changed, 42 insertions(+), 12 deletions(-) diff --git a/include/linux/ima.h b/include/linux/ima.h index d15100de6cdd..865332ecedcb 100644 --- a/include/linux/ima.h +++ b/include/linux/ima.h @@ -26,6 +26,9 @@ 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 int ima_measure_critical_data(const char *event_name, + const char *event_data_source, + const void *buf, int buf_len); #ifdef CONFIG_IMA_KEXEC extern void ima_add_kexec_buffer(struct kimage *image); @@ -104,6 +107,12 @@ static inline int ima_file_hash(struct file *file, char *buf, size_t buf_size) } static inline void ima_kexec_cmdline(int kernel_fd, const void *buf, int size) {} +static inline int ima_measure_critical_data(const char *event_name, + const char *event_data_source, + const void *buf, int buf_len) +{ + return -EOPNOTSUPP; +} #endif /* CONFIG_IMA */ #ifndef CONFIG_IMA_KEXEC diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index 99773dfa2541..e65ab067e700 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -266,10 +266,10 @@ void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file, struct evm_ima_xattr_data *xattr_value, int xattr_len, const struct modsig *modsig, int pcr, struct ima_template_desc *template_desc); -void process_buffer_measurement(struct inode *inode, const void *buf, - int buf_len, const char *eventname, - enum ima_hooks func, int pcr, - const char *func_data); +int process_buffer_measurement(struct inode *inode, const void *buf, + int buf_len, const char *eventname, + enum ima_hooks func, 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, diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index a8740b7ea417..129bcaaf13e2 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -736,10 +736,11 @@ int ima_load_data(enum kernel_load_data_id id) * * Based on policy, the buffer is measured into the ima log. */ -void process_buffer_measurement(struct inode *inode, const void *buf, - int buf_len, const char *eventname, - enum ima_hooks func, int pcr, - const char *func_data) + +int process_buffer_measurement(struct inode *inode, const void *buf, + int buf_len, const char *eventname, + enum ima_hooks func, int pcr, + const char *func_data) { int ret = 0; const char *audit_cause = "ENOMEM"; @@ -759,7 +760,7 @@ void process_buffer_measurement(struct inode *inode, const void *buf, u32 secid; if (!ima_policy_flag) - return; + return 0; /* * Both LSM hooks and auxilary based buffer measurements are @@ -773,7 +774,7 @@ void process_buffer_measurement(struct inode *inode, const void *buf, action = ima_get_action(inode, current_cred(), secid, 0, func, &pcr, &template, func_data); if (!(action & IMA_MEASURE)) - return; + return 0; } if (!pcr) @@ -788,7 +789,7 @@ void process_buffer_measurement(struct inode *inode, const void *buf, pr_err("template %s init failed, result: %d\n", (strlen(template->name) ? template->name : template->fmt), ret); - return; + return ret; } } @@ -820,7 +821,7 @@ void process_buffer_measurement(struct inode *inode, const void *buf, func_measure_str(func), audit_cause, ret, 0, ret); - return; + return ret; } /** @@ -847,6 +848,26 @@ void ima_kexec_cmdline(int kernel_fd, const void *buf, int size) fdput(f); } +/** + * ima_measure_critical_data - measure critical data + * @event_name: name for the given data + * @event_data_source: name of the event data source + * @buf: pointer to buffer containing data to measure + * @size: Number of bytes in buf + * + * Buffers can only be measured, not appraised. + */ +int ima_measure_critical_data(const char *event_name, + const char *event_data_source, + const void *buf, int buf_len) +{ + if (!event_name || !event_data_source || !buf || !buf_len) + return -EINVAL; + + return process_buffer_measurement(NULL, buf, buf_len, event_name, + CRITICAL_DATA, 0, event_data_source); +} + static int __init init_ima(void) { int error;