wpa_supplicant: Fix parsing errors on additional config file

If the -I<config> argument is used and the referenced configuration file
cannot be parsed, wpa_config_read() ended up freeing the main
configuration data structure and that resulted in use of freed memory in
such an error case. Fix this by not freeing the main config data and
handling the error case in the caller.

Signed-off-by: Jouni Malinen <j@w1.fi>

wpa_supplicant/config_file.c

@@ -464,7 +464,8 @@ struct wpa_config * wpa_config_read(const char *name, struct wpa_config *cfgp)
 
 #ifndef WPA_IGNORE_CONFIG_ERRORS
 	if (errors) {
-		wpa_config_free(config);
+		if (config != cfgp)
+			wpa_config_free(config);
 		config = NULL;
 		head = NULL;
 	}

wpa_supplicant/wpa_supplicant.c

@@ -1010,7 +1010,13 @@ int wpa_supplicant_reload_configuration(struct wpa_supplicant *wpa_s)
 			"file '%s' - exiting", wpa_s->confname);
 		return -1;
 	}
-	wpa_config_read(wpa_s->confanother, conf);
+	if (wpa_s->confanother &&
+	    !wpa_config_read(wpa_s->confanother, conf)) {
+		wpa_msg(wpa_s, MSG_ERROR,
+			"Failed to parse the configuration file '%s' - exiting",
+			wpa_s->confanother);
+		return -1;
+	}
 
 	conf->changed_parameters = (unsigned int) -1;
 
@@ -5219,7 +5225,13 @@ static int wpa_supplicant_init_iface(struct wpa_supplicant *wpa_s,
 			return -1;
 		}
 		wpa_s->confanother = os_rel2abs_path(iface->confanother);
-		wpa_config_read(wpa_s->confanother, wpa_s->conf);
+		if (wpa_s->confanother &&
+		    !wpa_config_read(wpa_s->confanother, wpa_s->conf)) {
+			wpa_printf(MSG_ERROR,
+				   "Failed to read or parse configuration '%s'.",
+				   wpa_s->confanother);
+			return -1;
+		}
 
 		/*
 		 * Override ctrl_interface and driver_param if set on command