[V4] IMA: support for per policy rule template formats

Message ID	20190618202428.10320-1-matthewgarrett@google.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <linux-integrity-owner@kernel.org> Date: Tue, 18 Jun 2019 13:24:28 -0700 Message-Id: <20190618202428.10320-1-matthewgarrett@google.com> Mime-Version: 1.0 Subject: [PATCH V4] IMA: support for per policy rule template formats From: Matthew Garrett <matthewgarrett@google.com> To: linux-integrity@vger.kernel.org Cc: zohar@linux.vnet.ibm.com, prsriva02@gmail.com, bauerman@linux.ibm.com, roberto.sassu@huawei.com, Matthew Garrett <matthewgarrett@google.com>, Matthew Garrett <mjg59@google.com>, Mimi Zohar <zohar@linux.ibm.com> Content-Type: text/plain; charset="UTF-8" Sender: linux-integrity-owner@vger.kernel.org Precedence: bulk
Series	[V4] IMA: support for per policy rule template formats \| expand [V4] IMA: support for per policy rule template formats

diff --git a/Documentation/ABI/testing/ima_policy b/Documentation/ABI/testing/ima_policy index 74c6702de74e..b383c1763610 100644 --- a/Documentation/ABI/testing/ima_policy +++ b/Documentation/ABI/testing/ima_policy @@ -24,8 +24,7 @@ Description: [euid=] [fowner=] [fsname=]] lsm: [[subj_user=] [subj_role=] [subj_type=] [obj_user=] [obj_role=] [obj_type=]] - option: [[appraise_type=]] [permit_directio] - + option: [[appraise_type=]] [template=] [permit_directio] base: func:= [BPRM_CHECK][MMAP_CHECK][CREDS_CHECK][FILE_CHECK][MODULE_CHECK] [FIRMWARE_CHECK] [KEXEC_KERNEL_CHECK] [KEXEC_INITRAMFS_CHECK] @@ -38,6 +37,8 @@ Description: fowner:= decimal value lsm: are LSM specific option: appraise_type:= [imasig] + template:= name of a defined IMA template type + (eg, ima-ng). Only valid when action is "measure". pcr:= decimal value default policy: diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index 2203451862d4..e7b9ea7732d9 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -146,7 +146,11 @@ void ima_add_violation(struct file *file, const unsigned char *filename, int ima_init_crypto(void); void ima_putc(struct seq_file *m, void *data, int datalen); void ima_print_digest(struct seq_file *m, u8 *digest, u32 size); +int template_desc_init_fields(const char *template_fmt, + const struct ima_template_field ***fields, + int *num_fields); struct ima_template_desc *ima_template_desc_current(void); +struct ima_template_desc *lookup_template_desc(const char *name); int ima_restore_measurement_entry(struct ima_template_entry *entry); int ima_restore_measurement_list(loff_t bufsize, void *buf); int ima_measurements_show(struct seq_file *m, void *v); @@ -195,7 +199,8 @@ enum ima_hooks { /* LIM API function definitions */ int ima_get_action(struct inode *inode, const struct cred *cred, u32 secid, - int mask, enum ima_hooks func, int *pcr); + int mask, enum ima_hooks func, int *pcr, + struct ima_template_desc **template_desc); 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, @@ -203,11 +208,13 @@ int ima_collect_measurement(struct integrity_iint_cache *iint, void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file, const unsigned char *filename, struct evm_ima_xattr_data *xattr_value, - int xattr_len, int pcr); + int xattr_len, int pcr, + struct ima_template_desc *template_desc); void ima_audit_measurement(struct integrity_iint_cache *iint, const unsigned char *filename); int ima_alloc_init_template(struct ima_event_data *event_data, - struct ima_template_entry **entry); + struct ima_template_entry **entry, + struct ima_template_desc *template_desc); int ima_store_template(struct ima_template_entry *entry, int violation, struct inode *inode, const unsigned char *filename, int pcr); @@ -216,7 +223,8 @@ const char *ima_d_path(const struct path *path, char **pathbuf, char *filename); /* IMA policy related functions */ int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid, - enum ima_hooks func, int mask, int flags, int *pcr); + enum ima_hooks func, int mask, int flags, int *pcr, + struct ima_template_desc **template_desc); 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 4aec6b035fe9..c0cf4bcfc82f 100644 --- a/security/integrity/ima/ima_api.c +++ b/security/integrity/ima/ima_api.c @@ -38,11 +38,17 @@ void ima_free_template_entry(struct ima_template_entry *entry) * ima_alloc_init_template - create and initialize a new template entry */ int ima_alloc_init_template(struct ima_event_data *event_data, - struct ima_template_entry **entry) + struct ima_template_entry **entry, + struct ima_template_desc *desc) { - struct ima_template_desc *template_desc = ima_template_desc_current(); + struct ima_template_desc *template_desc; int i, result = 0; + if (desc) + template_desc = desc; + else + template_desc = ima_template_desc_current(); + *entry = kzalloc(sizeof(**entry) + template_desc->num_fields * sizeof(struct ima_field_data), GFP_NOFS); if (!*entry) @@ -143,7 +149,7 @@ void ima_add_violation(struct file *file, const unsigned char *filename, /* can overflow, only indicator */ atomic_long_inc(&ima_htable.violations); - result = ima_alloc_init_template(&event_data, &entry); + result = ima_alloc_init_template(&event_data, &entry, NULL); if (result < 0) { result = -ENOMEM; goto err_out; @@ -166,6 +172,7 @@ void ima_add_violation(struct file *file, const unsigned char *filename, * MAY_APPEND) * @func: caller identifier * @pcr: pointer filled in if matched measure policy sets pcr= + * @template_desc: pointer filled in if matched measure policy sets template= * * The policy is defined in terms of keypairs: * subj=, obj=, type=, func=, mask=, fsmagic= @@ -178,13 +185,15 @@ 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) + int mask, enum ima_hooks func, int *pcr, + struct ima_template_desc **template_desc) { 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); + return ima_match_policy(inode, cred, secid, func, mask, flags, pcr, + template_desc); } /* @@ -279,7 +288,8 @@ int ima_collect_measurement(struct integrity_iint_cache *iint, void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file, const unsigned char *filename, struct evm_ima_xattr_data *xattr_value, - int xattr_len, int pcr) + int xattr_len, int pcr, + struct ima_template_desc *template_desc) { static const char op[] = "add_template_measure"; static const char audit_cause[] = "ENOMEM"; @@ -296,7 +306,7 @@ void ima_store_measurement(struct integrity_iint_cache *iint, if (iint->measured_pcrs & (0x1 << pcr)) return; - result = ima_alloc_init_template(&event_data, &entry); + result = ima_alloc_init_template(&event_data, &entry, template_desc); if (result < 0) { integrity_audit_msg(AUDIT_INTEGRITY_PCR, inode, filename, op, audit_cause, result, 0); diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c index 5fb7127bbe68..2f6536ab69e8 100644 --- a/security/integrity/ima/ima_appraise.c +++ b/security/integrity/ima/ima_appraise.c @@ -57,7 +57,7 @@ int ima_must_appraise(struct inode *inode, int mask, enum ima_hooks func) security_task_getsecid(current, &secid); return ima_match_policy(inode, current_cred(), secid, func, mask, - IMA_APPRAISE | IMA_HASH, NULL); + IMA_APPRAISE | IMA_HASH, NULL, NULL); } static int ima_fix_xattr(struct dentry *dentry, diff --git a/security/integrity/ima/ima_init.c b/security/integrity/ima/ima_init.c index ef6c3a26296e..368ef658a1cd 100644 --- a/security/integrity/ima/ima_init.c +++ b/security/integrity/ima/ima_init.c @@ -72,7 +72,7 @@ static int __init ima_add_boot_aggregate(void) } } - result = ima_alloc_init_template(&event_data, &entry); + result = ima_alloc_init_template(&event_data, &entry, NULL); if (result < 0) { audit_cause = "alloc_entry"; goto err_out; diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index 9e3ea8a3f2db..a7e7e2d7224c 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -199,7 +199,7 @@ static int process_measurement(struct file *file, const struct cred *cred, { struct inode *inode = file_inode(file); struct integrity_iint_cache *iint = NULL; - struct ima_template_desc *template_desc; + struct ima_template_desc *template_desc = NULL; char *pathbuf = NULL; char filename[NAME_MAX]; const char *pathname = NULL; @@ -217,7 +217,8 @@ static int process_measurement(struct file *file, const struct cred *cred, * bitmask based on the appraise/audit/measurement policy. * Included is the appraise submask. */ - action = ima_get_action(inode, cred, secid, mask, func, &pcr); + action = ima_get_action(inode, cred, secid, mask, func, &pcr, + &template_desc); violation_check = ((func == FILE_CHECK || func == MMAP_CHECK) && (ima_policy_flag & IMA_MEASURE)); if (!action && !violation_check) @@ -304,7 +305,6 @@ static int process_measurement(struct file *file, const struct cred *cred, goto out_locked; } - template_desc = ima_template_desc_current(); if ((action & IMA_APPRAISE_SUBMASK) || strcmp(template_desc->name, IMA_TEMPLATE_IMA_NAME) != 0) /* read 'security.ima' */ @@ -321,7 +321,8 @@ static int process_measurement(struct file *file, const struct cred *cred, if (action & IMA_MEASURE) ima_store_measurement(iint, file, pathname, - xattr_value, xattr_len, pcr); + xattr_value, xattr_len, pcr, + template_desc); if (rc == 0 && (action & IMA_APPRAISE_SUBMASK)) { inode_lock(inode); rc = ima_appraise_measurement(func, iint, file, pathname, diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index ec4efa8ea366..88ae36cfa69c 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -80,6 +80,7 @@ struct ima_rule_entry { int type; /* audit type */ } lsm[MAX_LSM_RULES]; char *fsname; + struct ima_template_desc *template; }; /* @@ -473,6 +474,7 @@ static int get_subaction(struct ima_rule_entry *rule, enum ima_hooks func) * @func: IMA hook identifier * @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 * * Measure decision based on func/mask/fsmagic and LSM(subj/obj/type) * conditions. @@ -482,7 +484,8 @@ static int get_subaction(struct ima_rule_entry *rule, enum ima_hooks func) * than writes so ima_match_policy() is classical RCU candidate. */ int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid, - enum ima_hooks func, int mask, int flags, int *pcr) + enum ima_hooks func, int mask, int flags, int *pcr, + struct ima_template_desc **template_desc) { struct ima_rule_entry *entry; int action = 0, actmask = flags | (flags << 1); @@ -514,6 +517,11 @@ int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid, if ((pcr) && (entry->flags & IMA_PCR)) *pcr = entry->pcr; + if (template_desc && entry->template) + *template_desc = entry->template; + else if (template_desc) + *template_desc = ima_template_desc_current(); + if (!actmask) break; } @@ -752,7 +760,7 @@ enum { Opt_uid_gt, Opt_euid_gt, Opt_fowner_gt, Opt_uid_lt, Opt_euid_lt, Opt_fowner_lt, Opt_appraise_type, Opt_permit_directio, - Opt_pcr, Opt_err + Opt_pcr, Opt_template, Opt_err }; static const match_table_t policy_tokens = { @@ -786,6 +794,7 @@ static const match_table_t policy_tokens = { {Opt_appraise_type, "appraise_type=%s"}, {Opt_permit_directio, "permit_directio"}, {Opt_pcr, "pcr=%s"}, + {Opt_template, "template=%s"}, {Opt_err, NULL} }; @@ -839,6 +848,7 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry) char *from; char *p; bool uid_token; + struct ima_template_desc *template_desc; int result = 0; ab = integrity_audit_log_start(audit_context(), GFP_KERNEL, @@ -1134,6 +1144,27 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry) else entry->flags |= IMA_PCR; + break; + case Opt_template: + ima_log_string(ab, "template", args[0].from); + if (entry->action != MEASURE) { + result = -EINVAL; + break; + } + template_desc = lookup_template_desc(args[0].from); + if (!template_desc || entry->template) { + result = -EINVAL; + } else { + /* + * template_desc_init_fields() does nothing + * if the template is already initialised, + * so it's safe to do this unconditionally + */ + template_desc_init_fields(template_desc->fmt, + &(template_desc->fields), + &(template_desc->num_fields)); + entry->template = template_desc; + } break; case Opt_err: ima_log_string(ab, "UNKNOWN", p); @@ -1410,6 +1441,8 @@ int ima_policy_show(struct seq_file *m, void *v) } } } + if (entry->template) + seq_printf(m, "template=%s ", entry->template->name); if (entry->flags & IMA_DIGSIG_REQUIRED) seq_puts(m, "appraise_type=imasig "); if (entry->flags & IMA_PERMIT_DIRECTIO) diff --git a/security/integrity/ima/ima_template.c b/security/integrity/ima/ima_template.c index b631b8bc7624..00dd5a434689 100644 --- a/security/integrity/ima/ima_template.c +++ b/security/integrity/ima/ima_template.c @@ -47,10 +47,6 @@ static const struct ima_template_field supported_fields[] = { #define MAX_TEMPLATE_NAME_LEN 15 static struct ima_template_desc *ima_template; -static struct ima_template_desc *lookup_template_desc(const char *name); -static int template_desc_init_fields(const char *template_fmt, - const struct ima_template_field ***fields, - int *num_fields); static int __init ima_template_setup(char *str) { @@ -108,7 +104,7 @@ static int __init ima_template_fmt_setup(char *str) } __setup("ima_template_fmt=", ima_template_fmt_setup); -static struct ima_template_desc *lookup_template_desc(const char *name) +struct ima_template_desc *lookup_template_desc(const char *name) { struct ima_template_desc *template_desc; int found = 0; @@ -153,9 +149,9 @@ static int template_fmt_size(const char *template_fmt) return j + 1; } -static int template_desc_init_fields(const char *template_fmt, - const struct ima_template_field ***fields, - int *num_fields) +int template_desc_init_fields(const char *template_fmt, + const struct ima_template_field ***fields, + int *num_fields) { const char *template_fmt_ptr; const struct ima_template_field *found_fields[IMA_TEMPLATE_NUM_FIELDS_MAX];

[V4] IMA: support for per policy rule template formats

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