From c0e0202736f55195104dad9fec98c20d0d15df21 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Petr=20Men=C5=A1=C3=ADk?= <pemensik@redhat.com>
Date: Fri, 21 Apr 2023 17:04:53 +0200
Subject: [PATCH] Correct releasing of serv_domain

In case the server->serv_domain points to domain also when it is not the
last server used, ensure the reference to last_server is always reset.
Some records might reference the server_domain, but cannot ever become
last_server. Such as server=/example.com/#

Correct detection of used server_domains for standard resolvers case.
Mark domain used even in that case, so it is not freed during
resolv.conf reading or other nameservers change.
---
 src/network.c | 40 +++++++++++++++++++++++++++++++---------
 1 file changed, 31 insertions(+), 9 deletions(-)

diff --git a/src/network.c b/src/network.c
index cf2f2e2..8152cac 100644
--- a/src/network.c
+++ b/src/network.c
@@ -1511,7 +1511,18 @@ void mark_servers(int flag)
     }
 }
 
-static void server_domains_cleanup(void)
+static void server_domains_pre_cleanup(void)
+{
+  struct server_domain *sd;
+
+  /* reset removed last_server. */
+  for (sd = daemon->server_domains; sd; sd = sd->next)
+    if ((sd->flags & SERV_MARK) == 0 && sd->last_server &&
+	(sd->last_server->flags & SERV_MARK) != 0)
+      sd->last_server = NULL;
+}
+
+static void server_domains_post_cleanup(void)
 {
   struct server_domain *sd, *tmp, **up;
 
@@ -1528,8 +1539,6 @@ static void server_domains_cleanup(void)
        }
       else {
         up = &sd->next;
-        if (sd->last_server && (sd->last_server->flags & SERV_MARK))
-	  sd->last_server = NULL;
       }
     }
 }
@@ -1538,7 +1547,7 @@ void cleanup_servers(void)
 {
   struct server *serv, *tmp, **up;
 
-  server_domains_cleanup();
+  server_domains_pre_cleanup();
 
   /* unlink and free anything still marked. */
   for (serv = daemon->servers, up = &daemon->servers; serv; serv = tmp) 
@@ -1552,10 +1561,16 @@ void cleanup_servers(void)
 	   free(serv->domain);
 	 free(serv);
        }
-      else 
-       up = &serv->next;
+      else
+       {
+         up = &serv->next;
+         if (serv->serv_domain && (serv->serv_domain->flags & SERV_MARK) != 0)
+           serv->serv_domain = NULL;
+       }
     }
 
+  server_domains_post_cleanup();
+
 #ifdef HAVE_LOOP
   /* Now we have a new set of servers, test for loops. */
   loop_send_probes();
@@ -1699,7 +1714,11 @@ static void server_domain_check(struct server *serv)
   if (sd)
     sd->flags &= (~SERV_MARK); /* found domain, mark active */
   else
-    server_domain_new(serv);
+    {
+      sd = server_domain_find_domain(serv->domain);
+      if (!sd)
+	server_domain_new(serv);
+    }
 }
 
 void check_servers(void)
@@ -1808,8 +1827,11 @@ void check_servers(void)
 	      else if (strlen(serv->domain) == 0)
 		s1 = _("default"), s2 = "";
 	      else
-		s1 = _("domain"), s2 = serv->domain;
-	      
+		{
+		  s1 = _("domain"), s2 = serv->domain;
+		  server_domain_check(serv);
+		}
+
 	      if (serv->flags & SERV_NO_ADDR)
 		{
 		  count--;
-- 
2.39.2