From 9f24fef5e91fb4df301242ede91ee7ac1b46b8a8 Mon Sep 17 00:00:00 2001
From: "Ondrej Zajicek (work)" <santiago@crfreenet.org>
Date: Wed, 20 Oct 2021 01:51:28 +0200
Subject: [PATCH] Conf: Fix crash during shutdown

BIRD implements shutdown by reconfiguring to fake empty configuration.
Such fake config structure is created from the last running config and
shares some data, including symbol table. This allows access to (removed)
routing tables and causes crash when 'show route' command is used during
shutdown.

Clean up symbol table, table list and links to default tables, so removed
routing tables cannot be accessed during shutdown.
---
 conf/conf.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/conf/conf.c b/conf/conf.c
index 58abcde1..a2b01667 100644
--- a/conf/conf.c
+++ b/conf/conf.c
@@ -520,6 +520,9 @@ order_shutdown(int gr)
   memcpy(c, config, sizeof(struct config));
   init_list(&c->protos);
   init_list(&c->tables);
+  init_list(&c->symbols);
+  memset(c->def_tables, 0, sizeof(c->def_tables));
+  HASH_INIT(c->sym_hash, c->pool, 4);
   c->shutdown = 1;
   c->gr_down = gr;