diff options
Diffstat (limited to 'security/smack/smack_access.c')
| -rw-r--r-- | security/smack/smack_access.c | 127 |
1 files changed, 91 insertions, 36 deletions
diff --git a/security/smack/smack_access.c b/security/smack/smack_access.c index 9f3705e9271..c062e9467b6 100644 --- a/security/smack/smack_access.c +++ b/security/smack/smack_access.c @@ -84,6 +84,8 @@ int log_policy = SMACK_AUDIT_DENIED; * * Do the object check first because that is more * likely to differ. + * + * Allowing write access implies allowing locking. */ int smk_access_entry(char *subject_label, char *object_label, struct list_head *rule_list) @@ -93,18 +95,23 @@ int smk_access_entry(char *subject_label, char *object_label, list_for_each_entry_rcu(srp, rule_list, list) { if (srp->smk_object == object_label && - srp->smk_subject == subject_label) { + srp->smk_subject->smk_known == subject_label) { may = srp->smk_access; break; } } + /* + * MAY_WRITE implies MAY_LOCK. + */ + if ((may & MAY_WRITE) == MAY_WRITE) + may |= MAY_LOCK; return may; } /** * smk_access - determine if a subject has a specific access to an object - * @subject_label: a pointer to the subject's Smack label + * @subject_known: a pointer to the subject's Smack label entry * @object_label: a pointer to the object's Smack label * @request: the access requested, in "MAY" format * @a : a pointer to the audit data @@ -115,10 +122,9 @@ int smk_access_entry(char *subject_label, char *object_label, * * Smack labels are shared on smack_list */ -int smk_access(char *subject_label, char *object_label, int request, - struct smk_audit_info *a) +int smk_access(struct smack_known *subject_known, char *object_label, + int request, struct smk_audit_info *a) { - struct smack_known *skp; int may = MAY_NOT; int rc = 0; @@ -127,7 +133,7 @@ int smk_access(char *subject_label, char *object_label, int request, * * A star subject can't access any object. */ - if (subject_label == smack_known_star.smk_known) { + if (subject_known == &smack_known_star) { rc = -EACCES; goto out_audit; } @@ -137,7 +143,7 @@ int smk_access(char *subject_label, char *object_label, int request, * An internet subject can access any object. */ if (object_label == smack_known_web.smk_known || - subject_label == smack_known_web.smk_known) + subject_known == &smack_known_web) goto out_audit; /* * A star object can be accessed by any subject. @@ -148,7 +154,7 @@ int smk_access(char *subject_label, char *object_label, int request, * An object can be accessed in any way by a subject * with the same label. */ - if (subject_label == object_label) + if (subject_known->smk_known == object_label) goto out_audit; /* * A hat subject can read any object. @@ -157,7 +163,7 @@ int smk_access(char *subject_label, char *object_label, int request, if ((request & MAY_ANYREAD) == request) { if (object_label == smack_known_floor.smk_known) goto out_audit; - if (subject_label == smack_known_hat.smk_known) + if (subject_known == &smack_known_hat) goto out_audit; } /* @@ -167,9 +173,9 @@ int smk_access(char *subject_label, char *object_label, int request, * good. A negative response from smk_access_entry() * indicates there is no entry for this pair. */ - skp = smk_find_entry(subject_label); rcu_read_lock(); - may = smk_access_entry(subject_label, object_label, &skp->smk_rules); + may = smk_access_entry(subject_known->smk_known, object_label, + &subject_known->smk_rules); rcu_read_unlock(); if (may > 0 && (request & may) == request) @@ -179,39 +185,42 @@ int smk_access(char *subject_label, char *object_label, int request, out_audit: #ifdef CONFIG_AUDIT if (a) - smack_log(subject_label, object_label, request, rc, a); + smack_log(subject_known->smk_known, object_label, request, + rc, a); #endif return rc; } /** - * smk_curacc - determine if current has a specific access to an object + * smk_tskacc - determine if a task has a specific access to an object + * @tsp: a pointer to the subject task * @obj_label: a pointer to the object's Smack label * @mode: the access requested, in "MAY" format * @a : common audit data * - * This function checks the current subject label/object label pair + * This function checks the subject task's label/object label pair * in the access rule list and returns 0 if the access is permitted, - * non zero otherwise. It allows that current may have the capability + * non zero otherwise. It allows that the task may have the capability * to override the rules. */ -int smk_curacc(char *obj_label, u32 mode, struct smk_audit_info *a) +int smk_tskacc(struct task_smack *subject, char *obj_label, + u32 mode, struct smk_audit_info *a) { - struct task_smack *tsp = current_security(); - char *sp = smk_of_task(tsp); + struct smack_known *skp = smk_of_task(subject); int may; int rc; /* * Check the global rule list */ - rc = smk_access(sp, obj_label, mode, NULL); + rc = smk_access(skp, obj_label, mode, NULL); if (rc == 0) { /* * If there is an entry in the task's rule list * it can further restrict access. */ - may = smk_access_entry(sp, obj_label, &tsp->smk_rules); + may = smk_access_entry(skp->smk_known, obj_label, + &subject->smk_rules); if (may < 0) goto out_audit; if ((mode & may) == mode) @@ -220,24 +229,37 @@ int smk_curacc(char *obj_label, u32 mode, struct smk_audit_info *a) } /* - * Return if a specific label has been designated as the - * only one that gets privilege and current does not - * have that label. + * Allow for priviliged to override policy. */ - if (smack_onlycap != NULL && smack_onlycap != sp) - goto out_audit; - - if (capable(CAP_MAC_OVERRIDE)) + if (rc != 0 && smack_privileged(CAP_MAC_OVERRIDE)) rc = 0; out_audit: #ifdef CONFIG_AUDIT if (a) - smack_log(sp, obj_label, mode, rc, a); + smack_log(skp->smk_known, obj_label, mode, rc, a); #endif return rc; } +/** + * smk_curacc - determine if current has a specific access to an object + * @obj_label: a pointer to the object's Smack label + * @mode: the access requested, in "MAY" format + * @a : common audit data + * + * This function checks the current subject label/object label pair + * in the access rule list and returns 0 if the access is permitted, + * non zero otherwise. It allows that current may have the capability + * to override the rules. + */ +int smk_curacc(char *obj_label, u32 mode, struct smk_audit_info *a) +{ + struct task_smack *tsp = current_security(); + + return smk_tskacc(tsp, obj_label, mode, a); +} + #ifdef CONFIG_AUDIT /** * smack_str_from_perm : helper to transalate an int to a @@ -249,6 +271,7 @@ out_audit: static inline void smack_str_from_perm(char *string, int access) { int i = 0; + if (access & MAY_READ) string[i++] = 'r'; if (access & MAY_WRITE) @@ -257,6 +280,10 @@ static inline void smack_str_from_perm(char *string, int access) string[i++] = 'x'; if (access & MAY_APPEND) string[i++] = 'a'; + if (access & MAY_TRANSMUTE) + string[i++] = 't'; + if (access & MAY_LOCK) + string[i++] = 'l'; string[i] = '\0'; } /** @@ -277,7 +304,10 @@ static void smack_log_callback(struct audit_buffer *ab, void *a) audit_log_untrustedstring(ab, sad->subject); audit_log_format(ab, " object="); audit_log_untrustedstring(ab, sad->object); - audit_log_format(ab, " requested=%s", sad->request); + if (sad->request[0] == '\0') + audit_log_format(ab, " labels_differ"); + else + audit_log_format(ab, " requested=%s", sad->request); } /** @@ -327,6 +357,25 @@ void smack_log(char *subject_label, char *object_label, int request, DEFINE_MUTEX(smack_known_lock); +struct hlist_head smack_known_hash[SMACK_HASH_SLOTS]; + +/** + * smk_insert_entry - insert a smack label into a hash map, + * + * this function must be called under smack_known_lock + */ +void smk_insert_entry(struct smack_known *skp) +{ + unsigned int hash; + struct hlist_head *head; + + hash = full_name_hash(skp->smk_known, strlen(skp->smk_known)); + head = &smack_known_hash[hash & (SMACK_HASH_SLOTS - 1)]; + + hlist_add_head_rcu(&skp->smk_hashed, head); + list_add_rcu(&skp->list, &smack_known_list); +} + /** * smk_find_entry - find a label on the list, return the list entry * @string: a text string that might be a Smack label @@ -336,12 +385,16 @@ DEFINE_MUTEX(smack_known_lock); */ struct smack_known *smk_find_entry(const char *string) { + unsigned int hash; + struct hlist_head *head; struct smack_known *skp; - list_for_each_entry_rcu(skp, &smack_known_list, list) { + hash = full_name_hash(string, strlen(string)); + head = &smack_known_hash[hash & (SMACK_HASH_SLOTS - 1)]; + + hlist_for_each_entry_rcu(skp, head, smk_hashed) if (strcmp(skp->smk_known, string) == 0) return skp; - } return NULL; } @@ -405,6 +458,8 @@ int smk_netlbl_mls(int level, char *catset, struct netlbl_lsm_secattr *sap, sap->flags |= NETLBL_SECATTR_MLS_CAT; sap->attr.mls.lvl = level; sap->attr.mls.cat = netlbl_secattr_catmap_alloc(GFP_ATOMIC); + if (!sap->attr.mls.cat) + return -ENOMEM; sap->attr.mls.cat->startbit = 0; for (cat = 1, cp = catset, byte = 0; byte < len; cp++, byte++) @@ -475,7 +530,7 @@ struct smack_known *smk_import_entry(const char *string, int len) * Make sure that the entry is actually * filled before putting it on the list. */ - list_add_rcu(&skp->list, &smack_known_list); + smk_insert_entry(skp); goto unlockout; } /* @@ -516,10 +571,10 @@ char *smk_import(const char *string, int len) * smack_from_secid - find the Smack label associated with a secid * @secid: an integer that might be associated with a Smack label * - * Returns a pointer to the appropriate Smack label if there is one, + * Returns a pointer to the appropriate Smack label entry if there is one, * otherwise a pointer to the invalid Smack label. */ -char *smack_from_secid(const u32 secid) +struct smack_known *smack_from_secid(const u32 secid) { struct smack_known *skp; @@ -527,7 +582,7 @@ char *smack_from_secid(const u32 secid) list_for_each_entry_rcu(skp, &smack_known_list, list) { if (skp->smk_secid == secid) { rcu_read_unlock(); - return skp->smk_known; + return skp; } } @@ -536,7 +591,7 @@ char *smack_from_secid(const u32 secid) * of a secid that is not on the list. */ rcu_read_unlock(); - return smack_known_invalid.smk_known; + return &smack_known_invalid; } /** |