From 94c3869941b0b92b9fe8c30a45848a64f78e6409 Mon Sep 17 00:00:00 2001
From: Felix Fietkau <nbd@nbd.name>
Date: Tue, 12 Aug 2025 19:47:53 +0200
Subject: [PATCH] interface: avoid memleaks on invalid interfaces

Free strings that were allocated with strdup in interface_alloc

Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
 config.c    |  2 +-
 interface.c | 19 ++++++++++++-------
 interface.h |  1 +
 3 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/config.c b/config.c
index f752da0..56943a3 100644
--- a/config.c
+++ b/config.c
@@ -193,7 +193,7 @@ config_parse_interface(struct uci_section *s, bool alias)
 error_free_config:
 	free(config);
 error:
-	free(iface);
+	interface_free(iface);
 }
 
 static void
diff --git a/interface.c b/interface.c
index 2ae94ae..3c9556a 100644
--- a/interface.c
+++ b/interface.c
@@ -702,14 +702,9 @@ interface_cleanup(struct interface *iface)
 	interface_cleanup_state(iface);
 }
 
-static void
-interface_do_free(struct interface *iface)
+void interface_free(struct interface *iface)
 {
-	interface_event(iface, IFEV_FREE);
-	interface_cleanup(iface);
 	free(iface->config);
-	netifd_ubus_remove_interface(iface);
-	avl_delete(&interfaces.avl, &iface->node.avl);
 	free(iface->zone);
 	free(iface->jail);
 	free(iface->jail_device);
@@ -717,6 +712,16 @@ interface_do_free(struct interface *iface)
 	free(iface);
 }
 
+static void
+interface_do_remove(struct interface *iface)
+{
+	interface_event(iface, IFEV_FREE);
+	interface_cleanup(iface);
+	netifd_ubus_remove_interface(iface);
+	avl_delete(&interfaces.avl, &iface->node.avl);
+	interface_free(iface);
+}
+
 static void
 interface_do_reload(struct interface *iface)
 {
@@ -739,7 +744,7 @@ interface_handle_config_change(struct interface *iface)
 		interface_do_reload(iface);
 		break;
 	case IFC_REMOVE:
-		interface_do_free(iface);
+		interface_do_remove(iface);
 		return;
 	}
 	if (iface->autostart)
diff --git a/interface.h b/interface.h
index c12a266..eef620c 100644
--- a/interface.h
+++ b/interface.h
@@ -184,6 +184,7 @@ extern struct vlist_tree interfaces;
 extern const struct uci_blob_param_list interface_attr_list;
 
 struct interface *interface_alloc(const char *name, struct blob_attr *config, bool dynamic);
+void interface_free(struct interface *iface);
 
 bool interface_add(struct interface *iface, struct blob_attr *config);
 bool interface_add_alias(struct interface *iface, struct blob_attr *config);
-- 
2.30.2