Merge branch 'master' into next

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