1 files changed, 127 insertions, 16 deletions

diff --git a/security/smack/smack_access.c b/security/smack/smack_access.c
index ac0a2707f6d4..513dc1aa16dd 100644
--- a/security/smack/smack_access.c
+++ b/security/smack/smack_access.c
@@ -59,11 +59,18 @@ LIST_HEAD(smack_known_list);
  */
 static u32 smack_next_secid = 10;
 
+/*
+ * what events do we log
+ * can be overwritten at run-time by /smack/logging
+ */
+int log_policy = SMACK_AUDIT_DENIED;
+
 /**
  * smk_access - determine if a subject has a specific access to an object
  * @subject_label: a pointer to the subject's Smack label
  * @object_label: a pointer to the object's Smack label
  * @request: the access requested, in "MAY" format
+ * @a : a pointer to the audit data
  *
  * This function looks up the subject/object pair in the
  * access rule list and returns 0 if the access is permitted,
@@ -78,10 +85,12 @@ static u32 smack_next_secid = 10;
  * will be on the list, so checking the pointers may be a worthwhile
  * optimization.
  */
-int smk_access(char *subject_label, char *object_label, int request)
+int smk_access(char *subject_label, char *object_label, int request,
+               struct smk_audit_info *a)
 {
         u32 may = MAY_NOT;
         struct smack_rule *srp;
+        int rc = 0;
 
         /*
          * Hardcoded comparisons.
@@ -89,8 +98,10 @@ 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 ||
-            strcmp(subject_label, smack_known_star.smk_known) == 0)
-                return -EACCES;
+            strcmp(subject_label, smack_known_star.smk_known) == 0) {
+                rc = -EACCES;
+                goto out_audit;
+        }
         /*
          * An internet object can be accessed by any subject.
          * Tasks cannot be assigned the internet label.
@@ -100,20 +111,20 @@ int smk_access(char *subject_label, char *object_label, int request)
             subject_label == smack_known_web.smk_known ||
             strcmp(object_label, smack_known_web.smk_known) == 0 ||
             strcmp(subject_label, smack_known_web.smk_known) == 0)
-                return 0;
+                goto out_audit;
         /*
          * A star object can be accessed by any subject.
          */
         if (object_label == smack_known_star.smk_known ||
             strcmp(object_label, smack_known_star.smk_known) == 0)
-                return 0;
+                goto out_audit;
         /*
          * An object can be accessed in any way by a subject
          * with the same label.
          */
         if (subject_label == object_label ||
             strcmp(subject_label, object_label) == 0)
-                return 0;
+                goto out_audit;
         /*
          * A hat subject can read any object.
          * A floor object can be read by any subject.
@@ -121,10 +132,10 @@ int smk_access(char *subject_label, char *object_label, int request)
         if ((request & MAY_ANYREAD) == request) {
                 if (object_label == smack_known_floor.smk_known ||
                     strcmp(object_label, smack_known_floor.smk_known) == 0)
-                        return 0;
+                        goto out_audit;
                 if (subject_label == smack_known_hat.smk_known ||
                     strcmp(subject_label, smack_known_hat.smk_known) == 0)
-                        return 0;
+                        goto out_audit;
         }
         /*
          * Beyond here an explicit relationship is required.
@@ -148,28 +159,36 @@ int smk_access(char *subject_label, char *object_label, int request)
          * This is a bit map operation.
          */
         if ((request & may) == request)
-                return 0;
-
-        return -EACCES;
+                goto out_audit;
+
+        rc = -EACCES;
+out_audit:
+#ifdef CONFIG_AUDIT
+        if (a)
+                smack_log(subject_label, object_label, request, 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)
+int smk_curacc(char *obj_label, u32 mode, struct smk_audit_info *a)
 {
         int rc;
+        char *sp = current_security();
 
-        rc = smk_access(current_security(), obj_label, mode);
+        rc = smk_access(sp, obj_label, mode, NULL);
         if (rc == 0)
-                return 0;
+                goto out_audit;
 
         /*
          * Return if a specific label has been designated as the
@@ -177,14 +196,105 @@ int smk_curacc(char *obj_label, u32 mode)
          * have that label.
          */
         if (smack_onlycap != NULL && smack_onlycap != current->cred->security)
-                return rc;
+                goto out_audit;
 
         if (capable(CAP_MAC_OVERRIDE))
                 return 0;
 
+out_audit:
+#ifdef CONFIG_AUDIT
+        if (a)
+                smack_log(sp, obj_label, mode, rc, a);
+#endif
         return rc;
 }
 
+#ifdef CONFIG_AUDIT
+/**
+ * smack_str_from_perm : helper to transalate an int to a
+ * readable string
+ * @string : the string to fill
+ * @access : the int
+ *
+ */
+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)
+                string[i++] = 'w';
+        if (access & MAY_EXEC)
+                string[i++] = 'x';
+        if (access & MAY_APPEND)
+                string[i++] = 'a';
+        string[i] = '\0';
+}
+/**
+ * smack_log_callback - SMACK specific information
+ * will be called by generic audit code
+ * @ab : the audit_buffer
+ * @a  : audit_data
+ *
+ */
+static void smack_log_callback(struct audit_buffer *ab, void *a)
+{
+        struct common_audit_data *ad = a;
+        struct smack_audit_data *sad = &ad->lsm_priv.smack_audit_data;
+        audit_log_format(ab, "lsm=SMACK fn=%s action=%s", ad->function,
+                         sad->result ? "denied" : "granted");
+        audit_log_format(ab, " subject=");
+        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);
+}
+
+/**
+ *  smack_log - Audit the granting or denial of permissions.
+ *  @subject_label : smack label of the requester
+ *  @object_label  : smack label of the object being accessed
+ *  @request: requested permissions
+ *  @result: result from smk_access
+ *  @a:  auxiliary audit data
+ *
+ * Audit the granting or denial of permissions in accordance
+ * with the policy.
+ */
+void smack_log(char *subject_label, char *object_label, int request,
+               int result, struct smk_audit_info *ad)
+{
+        char request_buffer[SMK_NUM_ACCESS_TYPE + 1];
+        struct smack_audit_data *sad;
+        struct common_audit_data *a = &ad->a;
+
+        /* check if we have to log the current event */
+        if (result != 0 && (log_policy & SMACK_AUDIT_DENIED) == 0)
+                return;
+        if (result == 0 && (log_policy & SMACK_AUDIT_ACCEPT) == 0)
+                return;
+
+        if (a->function == NULL)
+                a->function = "unknown";
+
+        /* end preparing the audit data */
+        sad = &a->lsm_priv.smack_audit_data;
+        smack_str_from_perm(request_buffer, request);
+        sad->subject = subject_label;
+        sad->object  = object_label;
+        sad->request = request_buffer;
+        sad->result  = result;
+        a->lsm_pre_audit = smack_log_callback;
+
+        common_lsm_audit(a);
+}
+#else /* #ifdef CONFIG_AUDIT */
+void smack_log(char *subject_label, char *object_label, int request,
+               int result, struct smk_audit_info *ad)
+{
+}
+#endif
+
 static DEFINE_MUTEX(smack_known_lock);
 
 /**
@@ -209,7 +319,8 @@ struct smack_known *smk_import_entry(const char *string, int len)
                 if (found)
                         smack[i] = '\0';
                 else if (i >= len || string[i] > '~' || string[i] <= ' ' ||
-                         string[i] == '/') {
+                         string[i] == '/' || string[i] == '"' ||
+                         string[i] == '\\' || string[i] == '\'') {
                         smack[i] = '\0';
                         found = 1;
                 } else