bugfix: address that strcat vulnerability in circuit.c

svn:r1273

src/or/circuit.c

@@ -790,29 +790,28 @@ void circuit_about_to_close_connection(connection_t *conn) {
 }
 
 void circuit_log_path(int severity, circuit_t *circ) {
-  static char b[1024];
+  char buf[1024];
+  char *s = buf;
   struct crypt_path_t *hop;
   char *states[] = {"closed", "waiting for keys", "open"};
   routerinfo_t *router;
   assert(circ->cpath);
 
-  sprintf(b,"circ (length %d, exit %s): ",
+  snprintf(s, sizeof(buf)-1, "circ (length %d, exit %s): ",
           circ->build_state->desired_path_len, circ->build_state->chosen_exit);
   hop=circ->cpath;
   do {
+    s = buf + strlen(buf);
     router = router_get_by_addr_port(hop->addr,hop->port);
     if(router) {
-      /* XXX strcat allows buffer overflow */
-      strcat(b,router->nickname);
-      strcat(b,"(");
-      strcat(b,states[hop->state]);
-      strcat(b,"),");
+      snprintf(s, sizeof(buf) - (s - buf), "%s(%s) ",
+               router->nickname, states[hop->state]);
     } else {
-      strcat(b,"UNKNOWN,");
+      snprintf(s, sizeof(buf) - (s - buf), "UNKNOWN ");
     }
     hop=hop->next;
   } while(hop!=circ->cpath);
-  log_fn(severity,"%s",b);
+  log_fn(severity,"%s",buf);
 }
 
 static void

src/or/config.c

@@ -345,7 +345,7 @@ static void print_usage(void) {
          );
 }
 
-int resolve_my_address(or_options_t *options) {
+static int resolve_my_address(or_options_t *options) {
   struct in_addr in;
   struct hostent *rent;
   char localhostname[256];
@@ -377,7 +377,7 @@ int resolve_my_address(or_options_t *options) {
   assert(rent->h_length == 4);
   memcpy(&in.s_addr, rent->h_addr,rent->h_length);
   if(is_internal_IP(in.s_addr)) {
-    log_fn(LOG_WARN,"Address '%s' resolves to '%s'. "
+    log_fn(LOG_WARN,"Address '%s' resolves to private IP '%s'. "
            "Please set the Address config option to be your public IP.",
            options->Address, inet_ntoa(in));
     return -1;

src/or/dirserv.c

@@ -341,7 +341,7 @@ list_running_servers(char **nicknames_out)
   for (i = 0; i<n; ++i) {
     if (i)
       strcat(cp, " ");
-    strcat(cp, nickname_lst[i]);
+    strcat(cp, nickname_lst[i]); /* can't overflow */
     while (*cp)
       ++cp;
   }

src/or/routerlist.c

@@ -1064,7 +1064,7 @@ router_add_exit_policy(routerinfo_t *router, directory_token_t *tok) {
     strcpy(newe->string, "accept ");
     newe->policy_type = EXIT_POLICY_ACCEPT;
   }
-  strcat(newe->string, arg);
+  strcat(newe->string, arg); /* can't overflow */
 
   address = arg;
   mask = strchr(arg,'/');