From: Guus Sliepen <guus@meshlink.io>
Date: Mon, 28 Oct 2019 20:14:17 +0000 (+0100)
Subject: Don't call terminate_connection() from meshlink_blacklist().
X-Git-Url: http://git.meshlink.io/?p=meshlink;a=commitdiff_plain;h=11662ed5b5c53be400f4de08ee715e461d491ec1

Don't call terminate_connection() from meshlink_blacklist().

If meshlink_blacklist() is called from a callback function, this can result
in a use-after-free bug. Instead, shut down the socket, so the event loop
will take care of it.
---

diff --git a/src/meshlink.c b/src/meshlink.c
index 98e02f7d..dd571190 100644
--- a/src/meshlink.c
+++ b/src/meshlink.c
@@ -2831,10 +2831,12 @@ void meshlink_blacklist(meshlink_handle_t *mesh, meshlink_node_t *node) {
 
 	logger(mesh, MESHLINK_DEBUG, "Blacklisted %s.\n", node->name);
 
-	//Immediately terminate any connections we have with the blacklisted node
+	/* Immediately shut down any connections we have with the blacklisted node.
+	 * We can't call terminate_connection(), because we might be called from a callback function.
+	 */
 	for list_each(connection_t, c, mesh->connections) {
 		if(c->node == n) {
-			terminate_connection(mesh, c, c->status.active);
+			shutdown(c->socket, SHUT_RDWR);
 		}
 	}
 
@@ -2846,10 +2848,6 @@ void meshlink_blacklist(meshlink_handle_t *mesh, meshlink_node_t *node) {
 	n->mtuprobes = 0;
 	n->status.udp_confirmed = false;
 
-	if(n->status.reachable) {
-		update_node_status(mesh, n);
-	}
-
 	pthread_mutex_unlock(&mesh->mutex);
 }