diff options
Diffstat (limited to 'security/smack/smack_access.c')
| -rw-r--r-- | security/smack/smack_access.c | 52 |
1 files changed, 34 insertions, 18 deletions
diff --git a/security/smack/smack_access.c b/security/smack/smack_access.c index 7ba8478..86453db 100644 --- a/security/smack/smack_access.c +++ b/security/smack/smack_access.c @@ -70,10 +70,11 @@ int log_policy = SMACK_AUDIT_DENIED; * smk_access_entry - look up matching access rule * @subject_label: a pointer to the subject's Smack label * @object_label: a pointer to the object's Smack label + * @rule_list: the list of rules to search * * This function looks up the subject/object pair in the - * access rule list and returns pointer to the matching rule if found, - * NULL otherwise. + * access rule list and returns the access mode. If no + * entry is found returns -ENOENT. * * NOTE: * Even though Smack labels are usually shared on smack_list @@ -85,13 +86,13 @@ int log_policy = SMACK_AUDIT_DENIED; * will be on the list, so checking the pointers may be a worthwhile * optimization. */ -int smk_access_entry(char *subject_label, char *object_label) +int smk_access_entry(char *subject_label, char *object_label, + struct list_head *rule_list) { - u32 may = MAY_NOT; + int may = -ENOENT; struct smack_rule *srp; - rcu_read_lock(); - list_for_each_entry_rcu(srp, &smack_rule_list, list) { + list_for_each_entry_rcu(srp, rule_list, list) { if (srp->smk_subject == subject_label || strcmp(srp->smk_subject, subject_label) == 0) { if (srp->smk_object == object_label || @@ -101,7 +102,6 @@ int smk_access_entry(char *subject_label, char *object_label) } } } - rcu_read_unlock(); return may; } @@ -129,7 +129,7 @@ int smk_access_entry(char *subject_label, char *object_label) int smk_access(char *subject_label, char *object_label, int request, struct smk_audit_info *a) { - u32 may = MAY_NOT; + int may = MAY_NOT; int rc = 0; /* @@ -181,13 +181,14 @@ int smk_access(char *subject_label, char *object_label, int request, * Beyond here an explicit relationship is required. * If the requested access is contained in the available * access (e.g. read is included in readwrite) it's - * good. - */ - may = smk_access_entry(subject_label, object_label); - /* - * This is a bit map operation. + * good. A negative response from smk_access_entry() + * indicates there is no entry for this pair. */ - if ((request & may) == request) + rcu_read_lock(); + may = smk_access_entry(subject_label, object_label, &smack_rule_list); + rcu_read_unlock(); + + if (may > 0 && (request & may) == request) goto out_audit; rc = -EACCES; @@ -212,12 +213,27 @@ out_audit: */ int smk_curacc(char *obj_label, u32 mode, struct smk_audit_info *a) { + struct task_smack *tsp = current_security(); + char *sp = smk_of_task(tsp); + int may; int rc; - char *sp = smk_of_current(); + /* + * Check the global rule list + */ rc = smk_access(sp, obj_label, mode, NULL); - if (rc == 0) - goto out_audit; + 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); + if (may < 0) + goto out_audit; + if ((mode & may) == mode) + goto out_audit; + rc = -EACCES; + } /* * Return if a specific label has been designated as the @@ -228,7 +244,7 @@ int smk_curacc(char *obj_label, u32 mode, struct smk_audit_info *a) goto out_audit; if (capable(CAP_MAC_OVERRIDE)) - return 0; + rc = 0; out_audit: #ifdef CONFIG_AUDIT |