1668 CVE 2011-3508 (ldap format string issues)

@@ -19,10 +19,11 @@
  * CDDL HEADER END
  */
 
 /*
  * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
  */
 
 /*
  * native LDAP related utility routines
  */

@@ -145,15 +146,32 @@
 int
 merge_SSD_filter(const ns_ldap_search_desc_t *desc,
         char **realfilter, const void *userdata)
 {
         int     len;
+        char *checker;
+
         if (realfilter == NULL)
                 return (NS_LDAP_INVALID_PARAM);
         *realfilter = NULL;
         if (desc == NULL || desc->filter == NULL || userdata == NULL)
                 return (NS_LDAP_INVALID_PARAM);
+
+        /* Parameter check.  We only want one %s here, otherwise bail. */
+        len = 0;        /* Reuse 'len' as "Number of %s hits"... */
+        checker = (char *)userdata;
+        do {
+                checker = strchr(checker, '%');
+                if (checker != NULL) {
+                        if (len > 0 || *(checker + 1) != 's')
+                                return (NS_LDAP_INVALID_PARAM);
+                        len++;  /* Got our %s. */
+                        checker += 2;
+                } else if (len != 1)
+                        return (NS_LDAP_INVALID_PARAM);
+        } while (checker != NULL);
+
         len = strlen(userdata) + strlen(desc->filter) + 1;
         *realfilter = (char *)malloc(len);
         if (*realfilter == NULL)
                 return (NS_LDAP_MEMORY);
         (void) sprintf(*realfilter, (char *)userdata, desc->filter);