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Diffstat (limited to 'security/smack/smack_access.c')
-rw-r--r--security/smack/smack_access.c52
1 files changed, 34 insertions, 18 deletions
diff --git a/security/smack/smack_access.c b/security/smack/smack_access.c
index 7ba8478f599e..86453db4333d 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